---------------------------------------------------------- Europa-List Digest Archive --- Total Messages Posted Wed 04/30/08: 21 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 01:16 AM - Re: Fuel tank - bulges and leakage. (streamlinedrafting@iinet.net.au) 2. 01:19 AM - Re: Resin for mod 72 (Charlie Laverty) 3. 02:55 AM - Re: Resin for mod 72 (Paul Stewart) 4. 03:35 AM - Re: Resin for mod 72 (scudrunner) 5. 06:12 AM - Re: Fuel tank - bulges and leakage. (Gary Leinberger) 6. 06:31 AM - Re: Emailing: Tank bulge (Peter Zutrauen) 7. 06:50 AM - Re: Fuel tank - bulges and leakage. (Alan Burrows) 8. 08:31 AM - Re: Emailing: Tank bulge (William Daniell) 9. 10:43 AM - Fuel tank - bulges and leakage. (Fred Klein) 10. 12:02 PM - Re: Fuel tank - bulges and leakage. (Jeff B) 11. 01:34 PM - Re: Fuel tank - bulges and leakage. (Fred Klein) 12. 01:48 PM - Re: Fuel tank - bulges and leakage. (Sidsel & Svein Johnsen) 13. 02:08 PM - Re: Fuel tank - bulges and leakage. (Jeff B) 14. 03:48 PM - Re: Fuel tank - bulges and leakage. (Graham Singleton) 15. 04:41 PM - Re: Fuel tank - bulges and leakage. (Karl Heindl) 16. 05:41 PM - Re: Emailing: Tank bulge (Rob Housman) 17. 06:14 PM - Re: Fuel tank - bulges and leakage. () 18. 07:06 PM - Re: Fuel tank - bulges and leakage. (Robert Borger) 19. 07:55 PM - Re: Fuel tank - bulges and leakage. (Keith Hickling) 20. 08:22 PM - Fuel tank - bulges and leakage. (Fred Klein) 21. 10:22 PM - Re: Fuel tank - bulges and leakage. (Venu Rao) ________________________________ Message 1 _____________________________________ Time: 01:16:14 AM PST US From: "streamlinedrafting@iinet.net.au" Subject: RE: Europa-List: Fuel tank - bulges and leakage. Hi guys, I am just about to start on a part built Europa XS #374 fuselarge is still in 2 pieces so I'm very interested to here these problems with the fuel tank (although the cockpit module is in). I have also heard of a similar case in Western Australia where fuel (unleaded petrol) had been sitting in the tank for about 8 - 12 months I think. The tank split on the fuel line. Does any one know or heard of the SMP system, link attached? http://www.schuetz.net/schuetz/de/industry_services/service/downloads/brochure_smp_eng lish.pdf Regards Peter H WA >Melding > > >Arnold; > >A143 has been down for awhile while I am developing an aluminum tank for it. I got the leaks after draining gasoline from the tank. What happens is that the tank expands and I am told that if it is drained it shrinks back slightly. My crack developed right alonside one of the layup straps in the saddle area. Get a small mechanics mirror and start probing around. The bulges you are seeing in the spar aperature are only an example of what happens to all of the surfaces of the tank. When I cutmy tankout of the cockpit seatback the top of the tank was all rippled where it had expanded and was constrained by the top of the seat back. The back flat surface also exhibited thesame phenomenon it was just constrained by the cockpit section. > >Steve Hagar >N40 SH >Mesa AZ > > >----- Original Message ----- >From: Arnold Kr. Hansen >To: europa-list@matronics.com >Sent: 4/29/2008 1:26:26 PM >Subject: Europa-List: Fuel tank - bulges and leakage. > > >Hi, > >Shortlybeforestart of taxiing, it was discovered that fuel was coming out of the fuselage on my Europa XS trigear (LN-ABM), through the access holes below the tank. Draining of the tank was started and the leakage stopped when 20 - 25 litres were remaining in the tank. > >Two daysbefore I had drained the tank completely since the aircraft had been stationary (in a heated hangar) since 1. july 2006 with app. 35 litres of mogas in the tank. The day of start upI filled 18 litres and checked all hose connections. Started the engine and runned it for 5 minutes to check hose connections to the recently installed oil thermostat. Then filled another 36 litres of mogas and started the engine forthelocal flight. > >Removing the wings, it was revealed that the tank front facing the wing spars, had great bulges, bulges inwards and outwards, and the centre one touching the aileron cross tube, see attached picture. I have not yet localized the crack, but I suspect the saddle section just ahead of the fibreglass bracket. To me the in and out shape of the bulges indicate compression stresses due to material expansion (caused by the fuel applied, 95 octane mogas?). And I think the crack is caused by shear stresses just forward of the bracket mentioned. > >I will appreciate comments and advice. At present I do not trust the material, polyethylene, used in the tank. Has anybody applied metal tanks? > >Regards >Arnold Kr. Hansen >Europa XS trigear, Kit No.381 > > ________________________________ Message 2 _____________________________________ Time: 01:19:13 AM PST US From: "Charlie Laverty" Subject: Re: Europa-List: Resin for mod 72 Hi all West system epoxy is readily available from boatyard & chandlery outlets, its used extensively in marine repairs. Gillian King ( Laverty) and Charlie Laverty Forest Bank 19 Argyll Terrace Tobermory PA75 6PB Tel 01688 301264 gillian.king3@virgin.net charleslaverty@googlemail.com ----- Original Message ----- From: "Carl Pattinson" Sent: Tuesday, April 29, 2008 7:22 PM Subject: Fw: Europa-List: Resin for mod 72 > > > > I believe West System resin is approved and is available from CFS > fiberglass supplies. I use them frequently as they stock everything you > are > likely to need and very reasonably priced eg: 5l of acetone for 9. Their > service is excellent and I usually recieve everything within 48 hrs of > ordering. > > http://www.cfsnet.co.uk/acatalog/CFS_Catalogue__WEST_EPOXY_SYSTEM_3.html > > AFE, formerly RD aviation sells Scheufler resin, also approved > > http://www.afeonline.com/shop/product_info.php?products_id=1898 > Ampreg have an approved supplier in Southampton somewhere but even the > smallest pack works out expensive (mainly due to the carriage). > > Hope this helps. > > Carl Pattinson > G-LABS > >> ----- Original Message ----- >> From: "Paul Stewart" >> To: >> Sent: Monday, April 28, 2008 10:57 PM >> Subject: Europa-List: Resin for mod 72 >> >> >>> >>> >>> Anyone know of a source of suitable epoxy for Mod 72 in the UK? >>> >>> Regards >>> >>> Paul >>> >>> >>> >>> >>> >>> >>> >> > > > ________________________________ Message 3 _____________________________________ Time: 02:55:42 AM PST US From: Paul Stewart Subject: Re: Europa-List: Resin for mod 72 Thanks for all the responses about resin. Looks like the 500g West kit should do and relatively easy to get hold of Regards paul G-GIDY ________________________________ Message 4 _____________________________________ Time: 03:35:21 AM PST US Subject: Re: Europa-List: Resin for mod 72 From: "scudrunner" Just in case you want an alternative to West, try Southern Valley Sailplanes: www.svsp.co.uk. They supply the Scheufler L285 system and all the bits & pieces (cups, mixing sticks, flox, gloves etc) Howard G-BVOW Visit - www.EuropaOwners.org ________________________________ Message 5 _____________________________________ Time: 06:12:47 AM PST US Subject: RE: Europa-List: Fuel tank - bulges and leakage. From: "Gary Leinberger" Steve - if you get a tank developed I would like to get info on it - and if you (or who you have fabricate them) are interested in selling them please let me know. I am going to try this new tank I just installed but have little faith in it - Gary Leinberger A237 gleinberger@millersville.edu ________________________________ From: owner-europa-list-server@matronics.com [mailto:owner-europa-list-server@matronics.com] On Behalf Of Steve Hagar Sent: Tuesday, April 29, 2008 8:52 PM Subject: RE: Europa-List: Fuel tank - bulges and leakage. Arnold; A143 has been down for awhile while I am developing an aluminum tank for it. I got the leaks after draining gasoline from the tank. What happens is that the tank expands and I am told that if it is drained it shrinks back slightly. My crack developed right alonside one of the layup straps in the saddle area. Get a small mechanics mirror and start probing around. The bulges you are seeing in the spar aperature are only an example of what happens to all of the surfaces of the tank. When I cut my tank out of the cockpit seatback the top of the tank was all rippled where it had expanded and was constrained by the top of the seat back. The back flat surface also exhibited thesame phenomenon it was just constrained by the cockpit section. Steve Hagar N40 SH Mesa AZ ----- Original Message ----- From: Arnold Kr. Hansen To: europa-list@matronics.com Sent: 4/29/2008 1:26:26 PM Subject: Europa-List: Fuel tank - bulges and leakage. Hi, Shortly before start of taxiing, it was discovered that fuel was coming out of the fuselage on my Europa XS trigear (LN-ABM), through the access holes below the tank. Draining of the tank was started and the leakage stopped when 20 - 25 litres were remaining in the tank. Two days before I had drained the tank completely since the aircraft had been stationary (in a heated hangar) since 1. july 2006 with app. 35 litres of mogas in the tank. The day of start up I filled 18 litres and checked all hose connections. Started the engine and runned it for 5 minutes to check hose connections to the recently installed oil thermostat. Then filled another 36 litres of mogas and started the engine for the local flight. Removing the wings, it was revealed that the tank front facing the wing spars, had great bulges, bulges inwards and outwards, and the centre one touching the aileron cross tube, see attached picture. I have not yet localized the crack, but I suspect the saddle section just ahead of the fibreglass bracket. To me the in and out shape of the bulges indicate compression stresses due to material expansion (caused by the fuel applied, 95 octane mogas?). And I think the crack is caused by shear stresses just forward of the bracket mentioned. I will appreciate comments and advice. At present I do not trust the material, polyethylene, used in the tank. Has anybody applied metal tanks? Regards Arnold Kr. Hansen Europa XS trigear, Kit No.381 ________________________________ Message 6 _____________________________________ Time: 06:31:49 AM PST US From: "Peter Zutrauen" Subject: Re: Europa-List: Emailing: Tank bulge I I remember correctly a few years back there was a change in the tanks from the factory, basically flourinating them to avoid these problems. Are these problematic tanks older pre-flourinated ones? Or are the new tanks also chemically inadequate? I'd hate to hear how much $$ a custom welded Alum would cost (let alone all the probs associated with weld quality leaks). Cheers, Pete Z. A239 *still* a pile of parts. On 4/29/08, Jeff B wrote: > > > While Baby Blue is in for repairs and installation of her new altitude > hold, I had occasion to look over the tank area, thoroughly. Sure enough, I > found evidence of contact between the center push rod and the tank, right > where you gents are point to. No real damage to the tank, but it was > definitely touching. I applied a bit of Velcro loop to the tank area to > guard against against further wear. I plan to either reposition the push > rod, or extend the brace to push the tank back into it's intended shape. > I'll let everyone know what I come up with and supply a pic or two... > > BTW, my new exhaust down pipe, just arrived. I'll install it tomorrow. > Many thanks to John and Rodger for the prompt shipping. I ordered it one > week ago, yesterday... > > Jeff, > Baby Blue > > Steven Pitt wrote: > > > Following Arnold's picture I thought I would take one of my tank and the > > bulge therein. Very similar but without a leak so far (!!??) as I know. > > Steve Pitt > > Tank bulge > > > > e-mail security > > ------------------------------------------------------------------------ > > > > > > ------------------------------------------------------------------------ > > > > Checked by AVG. > > > > ________________________________ Message 7 _____________________________________ Time: 06:50:01 AM PST US From: "Alan Burrows" Subject: RE: Europa-List: Fuel tank - bulges and leakage. Hi Everyone As you may know from previous posts. I had a tank split on me last year after bringing my aircraft over to the USA from UK. The aircraft had been used for several years in UK without problem. The tank had sat empty for over two months before being refilled with unleaded fuel again (thanks to US customs). The split occurred on the inside of the tunnel and was very difficult to see even with the wings removed. Initially we tried to repair the damage by cutting off the top of the tank applying a sealant to the inside and refitting the top, which seemed easier than removing the whole thing. The repair lasted about a week and then started to leak again! So the only solution was to remove the tank and replace it. The reason I tell this story again is to hopefully avoid anyone else either leaving the tank empty after it having previously been filled with fuel (I am convinced that was the cause of the split) or trying to effect a repair. The only solution in my opinion is to simply cut it out and replace the thing. The bulges seem to appear after a time on almost every Europa I have seen so I wouldn't be too concerned about that Hope that helps. Kind regards from sunny Florida :-) Alan ________________________________ Message 8 _____________________________________ Time: 08:31:14 AM PST US From: "William Daniell" Subject: RE: Europa-List: Emailing: Tank bulge I would be interested to know how you take the tank out . Do you cut the top of the cockpit module out? And if so what is the recommendation for putting the bit you cut out back on? Will PS I am putting in my tri gear main sockets ' without the top on. How on earth did anyone put them in with the top on??! From: owner-europa-list-server@matronics.com [mailto:owner-europa-list-server@matronics.com] On Behalf Of Peter Zutrauen Sent: Wednesday, April 30, 2008 08:28 Subject: Re: Europa-List: Emailing: Tank bulge I I remember correctly a few years back there was a change in the tanks from the factory, basically flourinating them to avoid these problems. Are these problematic tanks older pre-flourinated ones? Or are the new tanks also chemically inadequate? I'd hate to hear how much $$ a custom welded Alum would cost (let alone all the probs associated with weld quality leaks). Cheers, Pete Z. A239 *still* a pile of parts. On 4/29/08, Jeff B wrote: "mailto:topglock@cox.net" \ntopglock@cox.net> While Baby Blue is in for repairs and installation of her new altitude hold, I had occasion to look over the tank area, thoroughly. Sure enough, I found evidence of contact between the center push rod and the tank, right where you gents are point to. No real damage to the tank, but it was definitely touching. I applied a bit of Velcro loop to the tank area to guard against against further wear. I plan to either reposition the push rod, or extend the brace to push the tank back into it's intended shape. I'll let everyone know what I come up with and supply a pic or two... BTW, my new exhaust down pipe, just arrived. I'll install it tomorrow. Many thanks to John and Rodger for the prompt shipping. I ordered it one week ago, yesterday... Jeff, Baby Blue Steven Pitt wrote: Following Arnold's picture I thought I would take one of my tank and the bulge therein. Very similar but without a leak so far (!!??) as I know. Steve Pitt Tank bulge e-mail security ------------------------------------------------------------------------ ------------------------------------------------------------------------ "http://www.matronics.com/Navigator?Europa-List"http://www.matronics.com/ Nav igator?Europa-List "http://forums.matronics.com"http://forums.matronics.com "http://www.matronics.com/contribution"http://www.matronics.com/contribut ion Checked by AVG. 27-Apr-08 09:39 Checked by AVG. 27-Apr-08 09:39 ________________________________ Message 9 _____________________________________ Time: 10:43:10 AM PST US Subject: Europa-List: Fuel tank - bulges and leakage. From: Fred Klein "Troubling" is the kindest word I can utter on this topic. Heretofore I have eased my mind with the notions that fuel tank failures have been the result of previously-filled tanks left empty for extended periods and subject to abnormally high ambient temperatures (say, an Arizona summer). Now it appears in Arnold Hansen's case that a partially filled tank...left untouched for 20 months (with no leaks) but not subject to extreme temp. changes...then drained for two days and partially re-filled...is subject to failure. And Jeff B has been flying the pants off of Baby Blue and finds bulges and distortion in tank shape sufficient to contact control rods. Sounds to me that we have a very serious issue on our hands. I have CM installed, top just clecoed, and will be checking on the feasibility of supplementing the plywood and aluminum angle spacers...with the intent of minimizing tank bulging and preventing interference w/ the control rods. I reason that maintaining the shape of the tank as much as possible should reduce crack-inducing stresses. Fred -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. ________________________________ Message 10 ____________________________________ Time: 12:02:30 PM PST US From: Jeff B Subject: Re: Europa-List: Fuel tank - bulges and leakage. Fred and all, That would be my approach, if I were to build again. Support the front of the tank with ply, or some such and possibly spray foam all other areas, to add support. Seems this would completely encase the tank and keep it relatively ridged. Any other ideas? As the fleet ages, there are bound to be unforeseen problems that pop up. We just have to deal with them as they appear and hopefully, spare the new builders the pain... :) Jeff - Baby Blue Exhaust fixed and ready to take to the air, once again... Fred Klein wrote: > > "Troubling" is the kindest word I can utter on this topic. > > Heretofore I have eased my mind with the notions that fuel tank failures > have been the result of previously-filled tanks left empty for extended > periods and subject to abnormally high ambient temperatures (say, an > Arizona summer). > > Now it appears in Arnold Hansen's case that a partially filled > tank...left untouched for 20 months (with no leaks) but not subject to > extreme temp. changes...then drained for two days and partially > re-filled...is subject to failure. > > And Jeff B has been flying the pants off of Baby Blue and finds bulges > and distortion in tank shape sufficient to contact control rods. > > Sounds to me that we have a very serious issue on our hands. > > I have CM installed, top just clecoed, and will be checking on the > feasibility of supplementing the plywood and aluminum angle > spacers...with the intent of minimizing tank bulging and preventing > interference w/ the control rods. I reason that maintaining the shape of > the tank as much as possible should reduce crack-inducing stresses. > > Fred > > ________________________________ Message 11 ____________________________________ Time: 01:34:27 PM PST US Subject: Re: Europa-List: Fuel tank - bulges and leakage. From: Fred Klein On Wednesday, Apr 30, 2008, at 12:00 US/Pacific, Jeff B wrote: > As the fleet ages, there are bound to be unforeseen problems that pop > up. We just have to deal with them as they appear and hopefully, > spare the new builders the pain... :) Jeff...just love your "can do" attitude...helps me persevere! :-) Fred do not archive -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. ________________________________ Message 12 ____________________________________ Time: 01:48:59 PM PST US From: "Sidsel & Svein Johnsen" Subject: Re: Europa-List: Fuel tank - bulges and leakage. All, Preventing the tank from bulging too much forward will of course prevent it touching any of the controls or the wing spar (in which case the strap on the left spar might catch on the bulge during withdrawal/installation). The inherent problem with high density polyetylene (HDPE) without any barrier layer (which automobile tanks have, and the newer Europa tanks may have - this is now being looked into) is that it is permeable and components of the fuel get into the material and causes it to swell (and some gets through the tak walls and gives the typical "Europa smell"). Where the material is thick, as in the edges between the bottom and sides, sides and top, and sides to sides, the swelling is apparently negligible. This swelling cannot be stopped as such, so if the tank is prevented from buckling forward at all, it will bulge only inwards. This will probably not be one single large bulge in each panel, but smaller "wrinkles" that another contributor reported yesterday from his findings along the top and the back (where outward bulging is restricted). The best, given this undesired but unavoidable swelling, would be if the tank were of a simpler shape (say like a box without indentations and the saddle) and if we had no spacers to keep it away from the controls. Typical hard points as the saddle and the outlets at the bottom appears to be where cracks are developing in some cases. Even though the fuel components entering the permeable material also acts like softeners, local faults in the material may cause overstressing (e.g. thinner than intended material due to the fabrication process; maybe insufficient heating during the moulding). The spacers installed according to the Builders Manual could be typical danger areas as far as cracks. However, both on Arnold's tank and mine (which shows far less bulging - yet), the wave form of the bulging across the width of the tank is such that there is an inward bulge right behind the spacers and a forward bulge on either side. It is easy to envisage the stress that would be introuced if a spacer were installed where the tank naturally wants to bulge forward. So, based on what I have observed and learned about the tank material in these last few days, I would carefully evaluate where to stop the tank's bulging. Newer tanks have a stiff rib or indentation running across the front, which should help (one such installation will be inspected shortly by another owner). As for those still in the appropriate build stage, I would shape the BM spacers differently: Build the plate of thicker material, oval instead of rectangular (with long axis horizontal) and shape its thickness markedly convex (thich in the center, thinning towards a well rounded circumference). I am in contact with a polymer expert at a central Norwegian scientific institute. His immediate comment is that HDPE does not "dry out" if the tank is left empty, but I am awaiting his further comments to a host of follow-up questions with relevance to our particular tanks and how we operate our airplanes. Temperature definitely plays a part in the swelling. The hotter, the faster it swells, but I am still awaiting to hear from him whether HDPE swell more (higher maximum swell elongation) in hot weather than in cold. He also mentioned that the particular fuel used may play a role. When a major fuel supplier here introduced unleaded 98 octane mogas several years ago, it was found to "attack" polymers more aggressively than the previously used auto fuel did (we use unleaded 95 octane mogas in our Europas here in Norway). What I really hate about this issue is not knowing whether I have spent 10% or 90% of my tank's safety margin with the present bulging, and what does say 5mm more bulging translate into as far as approaching a crack somewhere? Regards, Svein LN-SKJ ________________________________ Message 13 ____________________________________ Time: 02:08:12 PM PST US From: Jeff B Subject: Re: Europa-List: Fuel tank - bulges and leakage. So, what you're saying is that the tank "grows" as it swells and will do so inwardly if not allowed to, outwardly. Hmmmm, that's something I hadn't considered. I'll have to rethink my solution. Thanks for the information, Svein. Please keep us up to speed on any additional information you should get... Jeff - Baby Blue Sidsel & Svein Johnsen wrote: > > > All, > > Preventing the tank from bulging too much forward will of course prevent > it touching any of the controls or the wing spar (in which case the > strap on the left spar might catch on the bulge during > withdrawal/installation). > > The inherent problem with high density polyetylene (HDPE) without any > barrier layer (which automobile tanks have, and the newer Europa tanks > may have - this is now being looked into) is that it is permeable and > components of the fuel get into the material and causes it to swell (and > some gets through the tak walls and gives the typical "Europa smell"). > Where the material is thick, as in the edges between the bottom and > sides, sides and top, and sides to sides, the swelling is apparently > negligible. This swelling cannot be stopped as such, so if the tank is > prevented from buckling forward at all, it will bulge only inwards. > This will probably not be one single large bulge in each panel, but > smaller "wrinkles" that another contributor reported yesterday from his > findings along the top and the back (where outward bulging is restricted). > > The best, given this undesired but unavoidable swelling, would be if the > tank were of a simpler shape (say like a box without indentations and > the saddle) and if we had no spacers to keep it away from the controls. > Typical hard points as the saddle and the outlets at the bottom appears > to be where cracks are developing in some cases. Even though the fuel > components entering the permeable material also acts like softeners, > local faults in the material may cause overstressing (e.g. thinner than > intended material due to the fabrication process; maybe insufficient > heating during the moulding). > > The spacers installed according to the Builders Manual could be typical > danger areas as far as cracks. However, both on Arnold's tank and mine > (which shows far less bulging - yet), the wave form of the bulging > across the width of the tank is such that there is an inward bulge right > behind the spacers and a forward bulge on either side. It is easy to > envisage the stress that would be introuced if a spacer were installed > where the tank naturally wants to bulge forward. > > So, based on what I have observed and learned about the tank material in > these last few days, I would carefully evaluate where to stop the tank's > bulging. Newer tanks have a stiff rib or indentation running across the > front, which should help (one such installation will be inspected > shortly by another owner). > > As for those still in the appropriate build stage, I would shape the BM > spacers differently: Build the plate of thicker material, oval instead > of rectangular (with long axis horizontal) and shape its thickness > markedly convex (thich in the center, thinning towards a well rounded > circumference). > > I am in contact with a polymer expert at a central Norwegian scientific > institute. His immediate comment is that HDPE does not "dry out" if the > tank is left empty, but I am awaiting his further comments to a host of > follow-up questions with relevance to our particular tanks and how we > operate our airplanes. Temperature definitely plays a part in the > swelling. The hotter, the faster it swells, but I am still awaiting to > hear from him whether HDPE swell more (higher maximum swell elongation) > in hot weather than in cold. He also mentioned that the particular fuel > used may play a role. When a major fuel supplier here introduced > unleaded 98 octane mogas several years ago, it was found to "attack" > polymers more aggressively than the previously used auto fuel did (we > use unleaded 95 octane mogas in our Europas here in Norway). > > What I really hate about this issue is not knowing whether I have spent > 10% or 90% of my tank's safety margin with the present bulging, and what > does say 5mm more bulging translate into as far as approaching a crack > somewhere? > > Regards, > Svein > LN-SKJ > > > > > > > ________________________________ Message 14 ____________________________________ Time: 03:48:29 PM PST US From: Graham Singleton Subject: Re: Europa-List: Fuel tank - bulges and leakage. I tend to blame the oil companies for putting all sorts of stuff in the fuel without a word to anyone. Could be wrong I suppose Graham Fred Klein wrote: > > "Troubling" is the kindest word I can utter on this topic. > > Heretofore I have eased my mind with the notions that fuel tank failures > have been the result of previously-filled tanks left empty for extended > periods and subject to abnormally high ambient temperatures (say, an > Arizona summer). > > Now it appears in Arnold Hansen's case that a partially filled > tank...left untouched for 20 months (with no leaks) but not subject to > extreme temp. changes...then drained for two days and partially > re-filled...is subject to failure. > > And Jeff B has been flying the pants off of Baby Blue and finds bulges > and distortion in tank shape sufficient to contact control rods. > > Sounds to me that we have a very serious issue on our hands. > > I have CM installed, top just clecoed, and will be checking on the > feasibility of supplementing the plywood and aluminum angle > spacers...with the intent of minimizing tank bulging and preventing > interference w/ the control rods. I reason that maintaining the shape of > the tank as much as possible should reduce crack-inducing stresses. > > Fred > > -- Graham Singleton Tel: +441629820187 Mob: +447739582005 ________________________________ Message 15 ____________________________________ Time: 04:41:30 PM PST US From: Karl Heindl Subject: RE: Europa-List: Fuel tank - bulges and leakage. When I inspected my tank a couple of years ago I noticed that the back wall had buckled inward, probably reducing its capacity somewhat. This may well have happened on other Europas, but unless you have a large opening at the top you would never see it. I have an opening for the fuel level probe, which allows me to get my whole arm into the tank. I was considering constr ucting some sort of internal framing, but couldn't come up with a good solu tion. Karl lock@cox.net>> > So, what you're saying is that the tank "grows" as it swel ls and will do > so inwardly if not allowed to, outwardly. Hmmmm, that's so mething I > hadn't considered. I'll have to rethink my solution. Thanks for the > information, Svein. Please keep us up to speed on any additional > i nformation you should get...> > Jeff - Baby Blue> > Sidsel & Svein Johnsen sidsel.svein@oslo.online.no>> > > > All,> > > > Preventing the tank from bu lging too much forward will of course prevent > > it touching any of the co ntrols or the wing spar (in which case the > > strap on the left spar might catch on the bulge during > > withdrawal/installation).> > > > The inheren t problem with high density polyetylene (HDPE) without any > > barrier laye r (which automobile tanks have, and the newer Europa tanks > > may have - t his is now being looked into) is that it is permeable and > > components of the fuel get into the material and causes it to swell (and > > some gets t hrough the tak walls and gives the typical "Europa smell"). > > Where the m aterial is thick, as in the edges between the bottom and > > sides, sides a nd top, and sides to sides, the swelling is apparently > > negligible. This swelling cannot be stopped as such, so if the tank is > > prevented from b uckling forward at all, it will bulge only inwards. > > This will probably not be one single large bulge in each panel, but > > smaller "wrinkles" tha t another contributor reported yesterday from his > > findings along the to p and the back (where outward bulging is restricted).> > > > The best, give n this undesired but unavoidable swelling, would be if the > > tank were of a simpler shape (say like a box without indentations and > > the saddle) a nd if we had no spacers to keep it away from the controls. > > Typical hard points as the saddle and the outlets at the bottom appears > > to be where cracks are developing in some cases. Even though the fuel > > components e ntering the permeable material also acts like softeners, > > local faults i n the material may cause overstressing (e.g. thinner than > > intended mate rial due to the fabrication process; maybe insufficient > > heating during the moulding).> > > > The spacers installed according to the Builders Manua l could be typical > > danger areas as far as cracks. However, both on Arno ld's tank and mine > > (which shows far less bulging - yet), the wave form of the bulging > > across the width of the tank is such that there is an in ward bulge right > > behind the spacers and a forward bulge on either side. It is easy to > > envisage the stress that would be introuced if a spacer were installed > > where the tank naturally wants to bulge forward.> > > > So, based on what I have observed and learned about the tank material in > > these last few days, I would carefully evaluate where to stop the tank's > > bulging. Newer tanks have a stiff rib or indentation running across the > > front, which should help (one such installation will be inspected > > shortly by another owner).> > > > As for those still in the appropriate bui ld stage, I would shape the BM > > spacers differently: Build the plate of thicker material, oval instead > > of rectangular (with long axis horizonta l) and shape its thickness > > markedly convex (thich in the center, thinni ng towards a well rounded > > circumference).> > > > I am in contact with a polymer expert at a central Norwegian scientific > > institute. His immedi ate comment is that HDPE does not "dry out" if the > > tank is left empty, but I am awaiting his further comments to a host of > > follow-up questions with relevance to our particular tanks and how we > > operate our airplane s. Temperature definitely plays a part in the > > swelling. The hotter, the faster it swells, but I am still awaiting to > > hear from him whether HDP E swell more (higher maximum swell elongation) > > in hot weather than in c old. He also mentioned that the particular fuel > > used may play a role. W hen a major fuel supplier here introduced > > unleaded 98 octane mogas seve ral years ago, it was found to "attack" > > polymers more aggressively than the previously used auto fuel did (we > > use unleaded 95 octane mogas in our Europas here in Norway).> > > > What I really hate about this issue is not knowing whether I have spent > > 10% or 90% of my tank's safety margin with the present bulging, and what > > does say 5mm more bulging translate into as far as approaching a crack > > somewhere?> > > > Regards,> > Svein> ===============> > > ________________________________ Message 16 ____________________________________ Time: 05:41:17 PM PST US From: "Rob Housman" Subject: RE: Europa-List: Emailing: Tank bulge In re: Tri-Gear main sockets One cusses for several hours and hopes the neighbors do not complain about the foul language. This was where I decided that the factory considered the Tri-Gear to be the ugly step child in the family. Best regards, Rob Housman Irvine, CA Europa XS Tri-Gear A070 Airframe complete From: owner-europa-list-server@matronics.com [mailto:owner-europa-list-server@matronics.com] On Behalf Of William Daniell Sent: Wednesday, April 30, 2008 8:26 AM Subject: RE: Europa-List: Emailing: Tank bulge I would be interested to know how you take the tank out . Do you cut the top of the cockpit module out? And if so what is the recommendation for putting the bit you cut out back on? Will PS I am putting in my tri gear main sockets - without the top on. How on earth did anyone put them in with the top on??! From: owner-europa-list-server@matronics.com [mailto:owner-europa-list-server@matronics.com] On Behalf Of Peter Zutrauen Sent: Wednesday, April 30, 2008 08:28 Subject: Re: Europa-List: Emailing: Tank bulge I I remember correctly a few years back there was a change in the tanks from the factory, basically flourinating them to avoid these problems. Are these problematic tanks older pre-flourinated ones? Or are the new tanks also chemically inadequate? I'd hate to hear how much $$ a custom welded Alum would cost (let alone all the probs associated with weld quality leaks). Cheers, Pete Z. A239 *still* a pile of parts. On 4/29/08, Jeff B wrote: While Baby Blue is in for repairs and installation of her new altitude hold, I had occasion to look over the tank area, thoroughly. Sure enough, I found evidence of contact between the center push rod and the tank, right where you gents are point to. No real damage to the tank, but it was definitely touching. I applied a bit of Velcro loop to the tank area to guard against against further wear. I plan to either reposition the push rod, or extend the brace to push the tank back into it's intended shape. I'll let everyone know what I come up with and supply a pic or two... BTW, my new exhaust down pipe, just arrived. I'll install it tomorrow. Many thanks to John and Rodger for the prompt shipping. I ordered it one week ago, yesterday... Jeff, Baby Blue Steven Pitt wrote: Following Arnold's picture I thought I would take one of my tank and the bulge therein. Very similar but without a leak so far (!!??) as I know. Steve Pitt Tank bulge e-mail security ------------------------------------------------------------------------ ------------------------------------------------------------------------ http://www.matronics.com/Navigator?Europa-List http://forums.matronics.com http://www.matronics.com/contribution Checked by AVG. 27-Apr-08 09:39 Checked by AVG. 27-Apr-08 09:39 ________________________________ Message 17 ____________________________________ Time: 06:14:34 PM PST US Subject: Re: Europa-List: Fuel tank - bulges and leakage. From: If anyone is interested, here is what we did to "Say "NO" to Crack (in fuel tank)": http://www.europaowners.org/modules.php?set_albumName=album233&op=modload&name=gallery&file=index&include=view_album.php Our CPM was in but top was off, but with a little effort you could drop the pushrod and do layup of tunnel from rear. Use plastic and BID, easy to polk BID flat from bottom of aeroplane, 2 person job though. Foam very dooable on completed plane. Ron Parigoris ________________________________ Message 18 ____________________________________ Time: 07:06:39 PM PST US From: Robert Borger Subject: Re: Europa-List: Fuel tank - bulges and leakage. Graham, There are so many ancillary ingredients added to MoGas it would be difficult to list them all on the side of the pump. According to the Wisconsin State Government, there are over 150 separate chemical in gasoline. There are detergents, solvents, oxidents, octane increasers and many other things beside C5 - C12 hydrocarbons. And it varies from Regular to Super Premium. Some of them are mandated by the government. Others are there to keep your carb or fuel injectors, etc., neat and tidy. Most of them change on a seasonal basis to provide fuel which meets Federal standards on emissions. Here in the U.S.A., there are even regional formulations. Fuels that provide the minimum emissions for the temperature/humidity ranges of the area. Fuels that are OK in Minnesota are verboten in Texas and vice-versa. Though, I bet if you wrote to your favorite oil company you could get a listing of ingredients. I doubt there are any "secret" ingredients. Check their website for information and contacts. You can also do a Google search on Gasoline Additives or start with the Wikipedia and ask about gasoline and/or gasoline additives. All provide good starter information. AvGas on the other hand is almost devoid of additives other than tetraethyl lead for antiknock. This is why AvGas stores well and MoGas doesn't. All those MoGas additives are volatile and will evaporate out of MoGas surprisingly quickly. Certainly there are no insidious reasons for the oil companies to hide what goes in their gas. It's just that most folks wouldn't know what 2,4-dimethyl-6-tert-butylphenol or methylcyclopentadienyl manganese tricarbonyl are or what they do in any case. Just some thoughts from a fellow who has been in "da o'l bidness" (as they used to say in Louisiana) for 30+ years. Check six, Bob Borger Europa Kit #A221 N914XL, XS Mono, Intercooled 914, Airmaster C/S http://www.europaowners.org/N914XL (95% done 95% to go) tail kit done, wings closed, cockpit module installed, pitch system in, landing gear complete, rudder system in with Singleton Mod, outrigger mod in, Fuselage Top on, lift/drag/flap pins in, wing incidence set, tie bar in, flap drive in, baggage bay in. Fuel system complete. Rotax and Airmaster installed. Mods 62, 66, 70 & 72 done. Completed the instrument panel install. Europa interior kit being installed. Installed windows. Working in - 25 Electrical, 28 Flaps, 30 Fuel System, 32 Tail, 34 Door Latches & 35 Doors, 37 Finishing. Mostly finishing these days. 3705 Lynchburg Dr. Corinth, TX 76208 Home: 940-497-2123 Cel: 817-992-1117 On Apr 30, 2008, at 17:47, Graham Singleton wrote: > > > > I tend to blame the oil companies for putting all sorts of stuff in > the fuel without a word to anyone. > Could be wrong I suppose > Graham ________________________________ Message 19 ____________________________________ Time: 07:55:00 PM PST US From: Keith Hickling Subject: Re: Europa-List: Fuel tank - bulges and leakage. Thanks for that Bob. So is the problem of cracks and bulges limited to the use of mogas? Has anyone using Avgas had bulges or cracks in the tank? For those of us who have not yet had fuel in the tank, would avgas be better? Keith Hickling, New Zealand. ----- Original Message ----- From: "Robert Borger" Sent: Thursday, May 01, 2008 2:03 PM Subject: Re: Europa-List: Fuel tank - bulges and leakage. > > Graham, > > There are so many ancillary ingredients added to MoGas it would be > difficult to list them all on the side of the pump. According to the > Wisconsin State Government, there are over 150 separate chemical in > gasoline. There are detergents, solvents, oxidents, octane increasers > and many other things beside C5 - C12 hydrocarbons. And it varies from > Regular to Super Premium. Some of them are mandated by the government. > Others are there to keep your carb or fuel injectors, etc., neat and > tidy. Most of them change on a seasonal basis to provide fuel which > meets Federal standards on emissions. Here in the U.S.A., there are even > regional formulations. Fuels that provide the minimum emissions for the > temperature/humidity ranges of the area. Fuels that are OK in Minnesota > are verboten in Texas and vice-versa. > > Though, I bet if you wrote to your favorite oil company you could get a > listing of ingredients. I doubt there are any "secret" ingredients. > Check their website for information and contacts. You can also do a > Google search on Gasoline Additives or start with the Wikipedia and ask > about gasoline and/or gasoline additives. All provide good starter > information. > > AvGas on the other hand is almost devoid of additives other than > tetraethyl lead for antiknock. This is why AvGas stores well and MoGas > doesn't. All those MoGas additives are volatile and will evaporate out > of MoGas surprisingly quickly. > > Certainly there are no insidious reasons for the oil companies to hide > what goes in their gas. It's just that most folks wouldn't know what > 2,4-dimethyl-6-tert-butylphenol or methylcyclopentadienyl manganese > tricarbonyl are or what they do in any case. > > Just some thoughts from a fellow who has been in "da o'l bidness" (as > they used to say in Louisiana) for 30+ years. > > Check six, > Bob Borger > Europa Kit #A221 N914XL, XS Mono, Intercooled 914, Airmaster C/S > http://www.europaowners.org/N914XL > (95% done 95% to go) tail kit done, wings closed, cockpit module > installed, pitch system in, landing gear complete, rudder system in with > Singleton Mod, outrigger mod in, Fuselage Top on, lift/drag/flap pins in, > wing incidence set, tie bar in, flap drive in, baggage bay in. Fuel > system complete. Rotax and Airmaster installed. Mods 62, 66, 70 & 72 > done. Completed the instrument panel install. Europa interior kit > being installed. Installed windows. Working in - 25 Electrical, 28 > Flaps, 30 Fuel System, 32 Tail, 34 Door Latches & 35 Doors, 37 Finishing. > Mostly finishing these days. > 3705 Lynchburg Dr. > Corinth, TX 76208 > Home: 940-497-2123 > Cel: 817-992-1117 > > > On Apr 30, 2008, at 17:47, Graham Singleton wrote: > >> > > >> >> I tend to blame the oil companies for putting all sorts of stuff in the >> fuel without a word to anyone. >> Could be wrong I suppose >> Graham > > > ________________________________ Message 20 ____________________________________ Time: 08:22:02 PM PST US Subject: Europa-List: Fuel tank - bulges and leakage. From: Fred Klein On Wednesday, Apr 30, 2008, at 13:46 US/Pacific, Sidsel & Svein Johnsen wrote: > > > All, > > Preventing the tank from bulging too much forward will of course > prevent it touching any of the controls or the wing spar (in which > case the strap on the left spar might catch on the bulge during > withdrawal/installation). Before getting Svein's thoughtful and informative post (thank you Svein!), I spent some time looking for a solution to potential bulging in my tank (which came w/ kit # A194, shipped from the factory in fall, 2000). In order to "contain" the (outward) bulging, I reset my spacers (which have generous curves at the corners of the specified lay up) to ensure a gap between tank (dry and never filled w/ anything) of between 1/8" and 1/4" and maintaining 1/4" clearance from the aileron control rod, I was planning to do the following: Insert a piece of 1/8" thick plywood, 6.25" x 34", w/ 1 layer of bid each side between the spacers and the front face of the tank, cushioning the plywood w/ 1/8" thick "sill sealer" (I believe it is a closed cell polypropylene foam available in 6" rolls at any building supply) between the plywood and the forward face of the tank. Prior to insertion, I would add a 3/4" x 2" x 34" foam stiffener w/ 2 layers bid on the forward face of the plywood. The plywood would be held in place w/ a 2 ply bid 2" wide tape which laps onto the underside of the FG "shelf" (previously installed as per manual). In doing this, my goal would be to resist "bulging" of the forward face of the tank. Having reviewed Svein's post, I will not be doing anything until we have more information, hopefully in answer to Svein's questions on the nature of the HDPE used in our tanks. I do appreciate so much the value of this forum as we attempt to address this insidious problem. Fred -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. ________________________________ Message 21 ____________________________________ Time: 10:22:50 PM PST US From: Venu Rao Subject: Re: Europa-List: Fuel tank - bulges and leakage. I'm rather concerned about this too. Going to have a look at my tank for signs of bulging. Almost certain I'm converting the mono to a conventional through Bob Berube. Just need to price it out. Do you know if the tank can be replaced easily? This forum is invaluable! Hope all's well. Cheers Venu Cell: (512) 771-3286 On Apr 30, 2008, at 22:18, Fred Klein wrote: > > On Wednesday, Apr 30, 2008, at 13:46 US/Pacific, Sidsel & Svein > Johnsen wrote: > >> > >> >> All, >> >> Preventing the tank from bulging too much forward will of course >> prevent it touching any of the controls or the wing spar (in which >> case the strap on the left spar might catch on the bulge during >> withdrawal/installation). > > Before getting Svein's thoughtful and informative post (thank you > Svein!), I spent some time looking for a solution to potential > bulging in my tank (which came w/ kit # A194, shipped from the > factory in fall, 2000). > > In order to "contain" the (outward) bulging, I reset my spacers > (which have generous curves at the corners of the specified lay up) > to ensure a gap between tank (dry and never filled w/ anything) of > between 1/8" and 1/4" and maintaining 1/4" clearance from the > aileron control rod, I was planning to do the following: > > Insert a piece of 1/8" thick plywood, 6.25" x 34", w/ 1 layer of > bid each side between the spacers and the front face of the tank, > cushioning the plywood w/ 1/8" thick "sill sealer" (I believe it is > a closed cell polypropylene foam available in 6" rolls at any > building supply) between the plywood and the forward face of the > tank. Prior to insertion, I would add a 3/4" x 2" x 34" foam > stiffener w/ 2 layers bid on the forward face of the plywood. The > plywood would be held in place w/ a 2 ply bid 2" wide tape which > laps onto the underside of the FG "shelf" (previously installed as > per manual). In doing this, my goal would be to resist "bulging" of > the forward face of the tank. > > Having reviewed Svein's post, I will not be doing anything until we > have more information, hopefully in answer to Svein's questions on > the nature of the HDPE used in our tanks. > > I do appreciate so much the value of this forum as we attempt to > address this insidious problem. > > Fred > > > -- > This message has been scanned for viruses and > dangerous content by MailScanner, and is > believed to be clean. > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message europa-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Europa-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/europa-list Browse Digests http://www.matronics.com/digest/europa-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.