---------------------------------------------------------- Pietenpol-List Digest Archive --- Total Messages Posted Mon 12/03/07: 19 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:04 AM - Re: Assembly Milestone (Phillips, Jack) 2. 06:00 AM - Re: final rigging (Phillips, Jack) 3. 06:22 AM - Re: Assembly Milestone (Jack T. Textor) 4. 07:01 AM - Re: Digital Scale (MikeD) 5. 07:17 AM - Re: Re: Vi Kaplers hinges (Bill Church) 6. 07:32 AM - Re: Re: Vi Kaplers hinges (Scott Knowlton) 7. 07:38 AM - Re: Assembly Milestone (HelsperSew@aol.com) 8. 08:05 AM - Assembly milestone (santiago morete) 9. 08:38 AM - Re: Re: Digital Scale (Bill Church) 10. 09:21 AM - Re: Digital Scale (Glenn Thomas) 11. 09:54 AM - mixing T88 (Oscar Zuniga) 12. 10:00 AM - Re: Re: Vi Kaplers hinges (Ryan Michals) 13. 10:21 AM - Re: Re: Vi Kaplers hinges (Ryan Michals) 14. 11:04 AM - Re: mixing T88 (Dave Abramson) 15. 11:09 AM - Re: Re: Digital Scale (Brian Kraut) 16. 11:09 AM - Re: Re: Digital Scale (Brian Kraut) 17. 11:35 AM - Re: Re: Vi Kaplers hinges (Jack T. Textor) 18. 02:30 PM - Re: Assembly milestone (Patrick Panzera) 19. 08:39 PM - Re: Assembly milestone (gcardinal) ________________________________ Message 1 _____________________________________ Time: 05:04:35 AM PST US Subject: RE: Pietenpol-List: Assembly Milestone From: "Phillips, Jack" Dan, Your Pietenpol looks great! Looks like you are about ready for cover now, and that was perhaps the most satisfying part of the whole project to me, where you transform a bare framework into a flying machine. Unless you are a real magician, I would doubt if you will have it ready for Brodhead this year (for me, covering and painting took the better part of a year, but I'm a notoriously slow worker). Much as I'd like to see it at Brodhead this year, please don't push it. The RV-10 community recently had their first fatal accident of an RV-10 and from the preliminary post-mortem it appears that a number of short cuts were made in order for the plane to make it to Oshkosh this year (it appears that the 40 hour flyoff was "pencil whipped" and the plane had less than 7 hours on it when it took off for OSH). Mods continued to be made to the airplane on almost every flight and apparently one of them went bad, killing the owner/builder. If necessary, a bunch of us can stop in at Poplar Grove on the way to or from Brodhead to see your project. Jack Phillips NX899JP _____ From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of HelsperSew@aol.com Sent: Sunday, December 02, 2007 8:16 PM Subject: Pietenpol-List: Assembly Milestone Group, Thanks to all who responded to my notice of progress. I really appreciate it, as it really means a lot to me. At this point I have a whole host of avenues to work on, not knowing which to take. There have been so many things that have hinged on this event. More FUN!!! Dan Helsper Poplar Grove, IL. _____ hottest products and top money wasters of 2007. _________________________________________________ This message is for the designated recipient only and may contain privilege d, proprietary or otherwise private information. If you have received it in error, please notify the sender immediately and delete the original. Any other use of the email by you is p rohibited. Dansk - Deutsch - Espanol - Francais - Italiano - Japanese - Nederlands - N orsk - Portuguese ________________________________ Message 2 _____________________________________ Time: 06:00:53 AM PST US Subject: RE: Pietenpol-List: final rigging From: "Phillips, Jack" Good luck, Rob. We need photos! Jack Phillips NX899JP Raleigh, NC _____ From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of RBush96589@aol.com Sent: Friday, November 30, 2007 7:54 PM Subject: Pietenpol-List: final rigging thanks for the input on my rigging question everyone. I am going to try to get it together this weekend, weather permitting.Jack and Gene if everything goes OK in the next couple of weekends,and I can get comfortable flying this thing by the time you get ready to make the trip to Brodhead I would be interested in making the trip with you. I live between Jackson and Lexington. Robert Bush _____ and top money wasters of 2007. _________________________________________________ This message is for the designated recipient only and may contain privilege d, proprietary or otherwise private information. If you have received it in error, please notify the sender immediately and delete the original. Any other use of the email by you is p rohibited. Dansk - Deutsch - Espanol - Francais - Italiano - Japanese - Nederlands - N orsk - Portuguese ________________________________ Message 3 _____________________________________ Time: 06:22:07 AM PST US Subject: RE: Pietenpol-List: Assembly Milestone From: "Jack T. Textor" Very good thoughts Jack. I had not heard about the 10, sad news. Jack www.textors.com do not archive ________________________________ Message 4 _____________________________________ Time: 07:01:07 AM PST US Subject: Pietenpol-List: Re: Digital Scale From: "MikeD" Glenn Thomas wrote: > I used it when making ribs to measure out one part of the T-88. One of the parts has a higher mass per volume so you have to measure the volume of the other part visually. It was good for getting the right amount to start with. T-88 instructions say to mix 2 parts of equal volume. When I was ready to mix by equal mass I could see that the volumes where different so the scale didn't really end up giving me the precision I was hoping for. I think you can get pretty good precision using identical translucent plastic containers and a block of wood or straight edge behind them as a reference point. > Having spent quite a few years in R&D which involved formulating a variety of potions and substances, including epoxy adhesive systems, I should point out something for informative purposes. The one major problem with your "discovery", is that volume ratios are not the gospel. Mass ratios are. Mixing by proper mass ratio is required to achieve a stoichiometric balance between the two components. Volume ratio takes second chair to mixing in the proper ratio of mass. Epoxies such as T-88 are formulated so that you can achieve a reasonably accurate A:B blend when mixing by volume, which is what most people leans towards as it is convenient and does not require a scale or balance to do so. If you are off a bit on either side of ideal the properties are not adversely affected, but there are limits to that. You will note the caution on the data sheet regardng addition of extra hardener for example - that is a complete no-no. In the world of epoxies and curatives, and in other adhesive chemistries as well, the raw material data contains a figure known as "equivalent weight" - which in simple terms is the mass (= weight on a scale) of one material that contains a known amount of reactive sites on the molecule. In order for each "A" site to react with a matching "B" site on the curative, you need an equal number of reactive sites on each side. When you have the equivalent weights of the materials, this is easy, and the two are mixed in proportion according to the equivalent weights, giving an equal number of "A" and "B" parts. Volume is in fact completely irrelevant and no more than a secondary parameter, and is only accounted for in the formulation and provided as a convenient method of mixing. Yes to one possible burning question: if the specific gravities of two materials are known, you can theoretically mix them correctly by volume. However, think of the things that could throw you off: (1) air bubbles in either material (2) tapered weighing vessels (3) human error (4) misreading due to the meniscus (the curve at the side of some liquid materials) (5) material stuck to the side of the weighing vessel (6) a combination of any of the above or other issues not listed None of which apply when mixing by weight! Don't be fooled by the manufacturer's listed 1:1 ratio by volume - there is a bag of tricks available to the formulator to allow them to adjust each side so that 1:1 volume gives the right mix ratio. However, they do this with prior knowledge of the correct mass ratios. A good rule to follow is, anytime you have access to two things - (1) a reasonably accurate scale, and (b) the A:B mass ratio specified by the manufacturer of the epoxy system - you should mix by mass versus by volume. In the long run your mixes will be more consistent and therefore by inference will be closer to the maximum properties of the adhesive system. In essence, you can bypass the secondary method of volume mixing and it's potential flwas, and go right to the horse's mouth by using a scale. In simple terms, while volumetric mixing is "good enough" in most cases, when you have the choice, would you not err towards the knowledge that you have not made a volume interpretation error and use the mass ratios instead? To me I can't do something in a less accurate manner when the better way is available and has far fewer caveats. For the cost of a scale good enough to do the job, which can be measured in tens of dollars and is therefore insignificant compared to the investment in time and money on a homebuilt, why piddle around? Hey, just my "$0.02".. [Wink] Mike D. -------- Piet-builder-who-hopes-to-be-flying-next-summer Read this topic online here: http://forums.matronics.com/viewtopic.php?p=150169#150169 ________________________________ Message 5 _____________________________________ Time: 07:17:51 AM PST US Subject: RE: Pietenpol-List: Re: Vi Kaplers hinges From: "Bill Church" Carson, I don't have Vi's hinges, so this isn't speaking from personal experience with them, but... BHP's plans show the empennage hinges to be mounted with #8 screws. Let's make the very safe assumption that these will be sufficient to carry the load (based on a total of four screws per hinge assembly - two for each component). Based on the dimension you have given, the holes in your hinges are .156" (5/32" diameter holes). Don't know the precision of your measurement (measured with a caliper or a ruler). In any case, the screw size closest to that hole is a #8 screw (.164" diameter). If I were you, I would go with #8-32 hardware (length to suit your particular build conditions - depending whether you recess the hinges into the wood or not). See if the screws will fit in the holes as-is. If necessary, open the holes in the hinges with a 11/64" drill (11/64" = .171", which will give you a nice .007" clearance). As I understand it, Vi's hinges are made of cast aluminum, so it wouldn't be a surprise at all if the holes were not perfect. If anyone out there with first-hand experience with Vi's hinges disagrees with anything I have just written, please let the list know. Bill C. ________________________________ Message 6 _____________________________________ Time: 07:32:06 AM PST US From: Scott Knowlton Subject: RE: Pietenpol-List: Re: Vi Kaplers hinges Gents I purchased Vi's hinges three years ago at Broadhead. Bill is correct abou t the # 8 screws. I purchased 8-32 x 11/2 machine screws from Leavens Avia tion in Toronto (ANM MS24693558) along with self locking nuts and washers. The countersink holes of Vi's hinges accept the machine screws heads perfe ctly. My two bits... Scott Knowlton Subject: RE: Pietenpol-List: Re: Vi Kaplers hingesDate: Mon, 3 Dec 2007 10: 17:19 -0500From: eng@canadianrogers.comTo: pietenpol-list@matronics.com Carson, I don't have Vi's hinges, so this isn't speaking from personal experience w ith them, but... BHP's plans show the empennage hinges to be mounted with #8 screws. Let's m ake the very safe assumption that these will be sufficient to carry the loa d (based on a total of four screws per hinge assembly - two for each compon ent). Based on the dimension you have given, the holes in your hinges are .156" ( 5/32" diameter holes). Don't know the precision of your measurement (measur ed with a caliper or a ruler). In any case, the screw size closest to that hole is a #8 screw (.164" diameter). If I were you, I would go with #8-32 h ardware (length to suit your particular build conditions - depending whethe r you recess the hinges into the wood or not). See if the screws will fit i n the holes as-is. If necessary, open the holes in the hinges with a 11/64" drill (11/64" = .171", which will give you a nice .007" clearance). As I understand it, Vi's hinges are made of cast aluminum, so it wouldn't be a surprise at all if the holes were not perfect. If anyone out there with first-hand experience with Vi's hinges disagrees w ith anything I have just written, please let the list know. Bill C. _________________________________________________________________ Introducing the City @ Live! Take a tour! http://getyourliveid.ca/?icid=LIVEIDENCA006 ________________________________ Message 7 _____________________________________ Time: 07:38:37 AM PST US From: HelsperSew@aol.com Subject: Re: Pietenpol-List: Assembly Milestone Hi Jack, Thank you for your kind words. That's good advice about not rushing. I still have much work to do before I start the covering, such as making the fuel lines and cowling. There is no way I can get it done for 2008, but Lord willing I should be there at Brodhead in '08. Dan Helsper Poplar Grove, IL. **************************************Check out AOL's list of 2007's hottest products. (http://money.aol.com/special/hot-products-2007?NCID=aoltop00030000000001) ________________________________ Message 8 _____________________________________ Time: 08:05:17 AM PST US From: santiago morete Subject: Pietenpol-List: Assembly milestone Congratulations Dan!!! Beautiful work. Thanks for the pictures! Saludos Santiago --------------------------------- Compart video en la ventana de tus mensajes y tambin tus fotos de Flickr. Usel Nuevo Yahoo! Messenger versin Beta. Visit http://ar.beta.messenger.yahoo.com/ ________________________________ Message 9 _____________________________________ Time: 08:38:18 AM PST US Subject: RE: Pietenpol-List: Re: Digital Scale From: "Bill Church" Like Einstein said, "Things should be made as simple as possible, but not any simpler." So, when it comes to mixing epoxy, which of the following is simpler: Mix equal parts (by volume) of Part A and Part B. Or Mix (by mass) Parts A and B in a ratio of 100 to 83. (or is that 83 to 100)? Human nature being what it is, one time or another, someone is going to do it the wrong way around,and instead of being off by a few percent (due to normal human error), they're going to be off by about 40%. And how many guys are going to forget to reset the scale (or deduct the mass of the cup)? I'm pretty sure that when they formulated T88 (or any similar structural epoxy like it) they intentionally made it so there was a one-to-one ratio by volume, because that's the simplest way to measure liquids. That's probably why they say to mix it that way on the bottles. It's easier for the builder, and it's probably better (liability-wise) for the epoxy formulator. So, if the instructions say to mix equal parts by volume, why not do that? When mixing my epoxy, I use the same clear graduated plastic cups that Clif recommended (Lee Valley # 56Z82.02). Yes, the cups are tapered, but they have multiple graduations in ounces, millilitres and drams - take your pick. I also leave the unused portion of my mix in the cup, which I label with the date, to keep a record of my mixes. There is no transfer of material from one cup to another - it's all done in the one cup. Fill up to the mark for 3/8 of an ounce with Part A, and let it settle, and all air bubbles rise. Re-check after settling, to make sure the volume is right. Then add Part B almost up to the mark for 3/4 of an ounce, let that settle, and add a little bit more (if necessary) to get the total volume to 3/4 of an ounce. Mix thoroughly for several minutes non-stop, then let it sit for ten minutes, for the tiny air bubbles to dissipate, and apply. Works like a charm. <> I also use their glue spreaders (Lee valley #99K50.10) to mix and apply the epoxy. After the epoxy has hardened, it flakes off, and the spreader can be re-used over and over again. <> Personally, I think the average builder is waaaaaay more likely to screw up measuring by mass in a ratio of .83 to 1 than by measuring by volume in a ratio of 1 to 1. Why make life more complicated? My $.02 (Canadian) Bill C. ________________________________ Message 10 ____________________________________ Time: 09:21:38 AM PST US Subject: Pietenpol-List: Re: Digital Scale From: "Glenn Thomas" Resin 100 parts / Hardener 83 parts BY WEIGHT - From a call to System 3 No problem with my "discovery". I got the mfr ration by weighing what I visually compared. If you take your time, take your project seriously and measure carefully, you will be fine. I agree with every point Bill made and have been using same type of mixing process as he has and don't think new builders should have cause for concern if they have been measuring visually by equal volume and doing it carefully. -------- Glenn Thomas N????? http://www.flyingwood.com Read this topic online here: http://forums.matronics.com/viewtopic.php?p=150202#150202 ________________________________ Message 11 ____________________________________ Time: 09:54:42 AM PST US From: Oscar Zuniga Subject: Pietenpol-List: mixing T88 I'm no expert on adhesives or epoxies and I don't want anyone hurt, injured, damaged, or offended. With that said- I'm going to come clean and say that when I first started building my "Flying Squirrel" I got disposable syringes and clear plastic mixing cups and all of that and it didn't last one building session. Too much sticky mess, hassle, and I couldn't see that it was needed so I started mixing my T88 by eye in the small Dixie cups (unwaxed) with wooden tongue depressors and that's the only way I've ever done it since. I never need or mix large batches and I always leave the stick (actually half a stick... I cut them in half and use the other half next batch; cheapskate) standing in the cup. Next day, the stick is always solidly glued to the cup and the epoxy is rock-hard. May my soul rest in peace when they recover my body from the unglued airframe of my Squirrel or the repairs I've made on the Piet, but so far I have never used scales or syringes when measuring or mixing T88 and have always found my wood joints to be strong and complete using moderate clamping pressure and good squeeze-out at the joints. I pour what appear to be equal puddles of resin and hardener in the cup, mix thoroughly, and either I've been lucky or the stuff is pretty flexible on the ratio because it works just fine. If I were to need a larger batch I would use postal scales, which my buddy has in the hangar (the Pelouze that was mentioned here before). Do not archive and please do not follow my example either, but that's the simple truth for what's worked for me for years now. Oscar Zuniga San Antonio, TX mailto: taildrags@hotmail.com website at http://www.flysquirrel.net ________________________________ Message 12 ____________________________________ Time: 10:00:06 AM PST US From: Ryan Michals Subject: RE: Pietenpol-List: Re: Vi Kaplers hinges Does anyone know who was selling the machined hinges adjacent to the Vi's hinges at Brodhead '08? I purchased the hinges but he had some other products I am interested in. Ryan M Scott Knowlton wrote: .hmmessage P { margin:0px; padding:0px } body.hmmessage { FONT-SIZE: 10pt; FONT-FAMILY:Tahoma } Gents I purchased Vi's hinges three years ago at Broadhead. Bill is correct about the # 8 screws. I purchased 8-32 x 11/2 machine screws from Leavens Aviation in Toronto (ANM MS24693558) along with self locking nuts and washers. The countersink holes of Vi's hinges accept the machine screws heads perfectly. My two bits... Scott Knowlton --------------------------------- Subject: RE: Pietenpol-List: Re: Vi Kaplers hinges From: eng@canadianrogers.com Carson, I don't have Vi's hinges, so this isn't speaking from personal experience with them, but... BHP's plans show the empennage hinges to be mounted with #8 screws. Let's make the very safe assumption that these will be sufficient to carry the load (based on a total of four screws per hinge assembly - two for each component). Based on the dimension you have given, the holes in your hinges are .156" (5/32" diameter holes). Don't know the precision of your measurement (measured with a caliper or a ruler). In any case, the screw size closest to that hole is a #8 screw (.164" diameter). If I were you, I would go with #8-32 hardware (length to suit your particular build conditions - depending whether you recess the hinges into the wood or not). See if the screws will fit in the holes as-is. If necessary, open the holes in the hinges with a 11/64" drill (11/64" = .171", which will give you a nice .007" clearance). As I understand it, Vi's hinges are made of cast aluminum, so it wouldn't be a surprise at all if the holes were not perfect. If anyone out there with first-hand experience with Vi's hinges disagrees with anything I have just written, please let the list know. Bill C. blank>http://www.matronics.com/contribution " target=_blank>http://www.matronics.com/Navigator?Pietenpol-List p://forums.matronics.com --------------------------------- HO HO HO, if you've been naughty this year, email Santa! Visit asksanta.ca to learn more! --------------------------------- Be a better sports nut! Let your teams follow you with Yahoo Mobile. Try it now. ________________________________ Message 13 ____________________________________ Time: 10:21:26 AM PST US From: Ryan Michals Subject: RE: Pietenpol-List: Re: Vi Kaplers hinges I am getting a little ahead of myself. I meant Brodhead '07. do not archive Ryan Michals wrote: Does anyone know who was selling the machined hinges adjacent to the Vi's hinges at Brodhead '08? I purchased the hinges but he had some other products I am interested in. Ryan M Scott Knowlton wrote: .hmmessage P { margin:0px; padding:0px } body.hmmessage { FONT-SIZE: 10pt; FONT-FAMILY:Tahoma } Gents I purchased Vi's hinges three years ago at Broadhead. Bill is correct about the # 8 screws. I purchased 8-32 x 11/2 machine screws from Leavens Aviation in Toronto (ANM MS24693558) along with self locking nuts and washers. The countersink holes of Vi's hinges accept the machine screws heads perfectly. My two bits... Scott Knowlton --------------------------------- Subject: RE: Pietenpol-List: Re: Vi Kaplers hinges From: eng@canadianrogers.com Carson, I don't have Vi's hinges, so this isn't speaking from personal experience with them, but... BHP's plans show the empennage hinges to be mounted with #8 screws. Let's make the very safe assumption that these will be sufficient to carry the load (based on a total of four screws per hinge assembly - two for each component). Based on the dimension you have given, the holes in your hinges are .156" (5/32" diameter holes). Don't know the precision of your measurement (measured with a caliper or a ruler). In any case, the screw size closest to that hole is a #8 screw (.164" diameter). If I were you, I would go with #8-32 hardware (length to suit your particular build conditions - depending whether you recess the hinges into the wood or not). See if the screws will fit in the holes as-is. If necessary, open the holes in the hinges with a 11/64" drill (11/64" = .171", which will give you a nice .007" clearance). As I understand it, Vi's hinges are made of cast aluminum, so it wouldn't be a surprise at all if the holes were not perfect. If --------------------------------- Be a better sports nut! Let your teams follow you ">Try it now. --------------------------------- Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. ________________________________ Message 14 ____________________________________ Time: 11:04:07 AM PST US From: "Dave Abramson" Subject: RE: Pietenpol-List: mixing T88 Ditto! I have been just eye-balling as well...... Has always cured hard as a rock! I do not think T-88 is not real critical to the amount. It just needs to be "close". My 2 cents......... Dave 2 years and still building......... But, flying my 140! -----Original Message----- From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com]On Behalf Of Oscar Zuniga Sent: Monday, December 03, 2007 9:54 AM Subject: Pietenpol-List: mixing T88 I'm no expert on adhesives or epoxies and I don't want anyone hurt, injured, damaged, or offended. With that said- I'm going to come clean and say that when I first started building my "Flying Squirrel" I got disposable syringes and clear plastic mixing cups and all of that and it didn't last one building session. Too much sticky mess, hassle, and I couldn't see that it was needed so I started mixing my T88 by eye in the small Dixie cups (unwaxed) with wooden tongue depressors and that's the only way I've ever done it since. I never need or mix large batches and I always leave the stick (actually half a stick... I cut them in half and use the other half next batch; cheapskate) standing in the cup. Next day, the stick is always solidly glued to the cup and the epoxy is rock-hard. May my soul rest in peace when they recover my body from the unglued airframe of my Squirrel or the repairs I've made on the Piet, but so far I have never used scales or syringes when measuring or mixing T88 and have always found my wood joints to be strong and complete using moderate clamping pressure and good squeeze-out at the joints. I pour what appear to be equal puddles of resin and hardener in the cup, mix thoroughly, and either I've been lucky or the stuff is pretty flexible on the ratio because it works just fine. If I were to need a larger batch I would use postal scales, which my buddy has in the hangar (the Pelouze that was mentioned here before). Do not archive and please do not follow my example either, but that's the simple truth for what's worked for me for years now. Oscar Zuniga San Antonio, TX mailto: taildrags@hotmail.com website at http://www.flysquirrel.net ________________________________ Message 15 ____________________________________ Time: 11:09:05 AM PST US From: "Brian Kraut" Subject: RE: Pietenpol-List: Re: Digital Scale RE: Pietenpol-List: Re: Digital ScaleOh, and one other thing. I take a Sharpie and write "100" one one bottle and "83" on the other as soon as I get more T-88. Keeps down the confusion when mixing and chances for error. Brian Kraut Engineering Alternatives, Inc. www.engalt.com ________________________________ Message 16 ____________________________________ Time: 11:09:06 AM PST US From: "Brian Kraut" Subject: RE: Pietenpol-List: Re: Digital Scale Mixing by weight also has a some other advantages. One I like a lot is that if I did not mix enough I can throw the same mixing cup with the mixing stick and leftover epoxy on the sides of the cup back on the scale and hit the tare button. Then I can start a fresh batch in the same cup. There is also a lot less waste when you are not using separate syringes or something for your measuring. Brian Kraut Engineering Alternatives, Inc. www.engalt.com -----Original Message----- From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com]On Behalf Of MikeD Sent: Monday, December 03, 2007 10:01 AM Subject: Pietenpol-List: Re: Digital Scale Glenn Thomas wrote: > I used it when making ribs to measure out one part of the T-88. One of the parts has a higher mass per volume so you have to measure the volume of the other part visually. It was good for getting the right amount to start with. T-88 instructions say to mix 2 parts of equal volume. When I was ready to mix by equal mass I could see that the volumes where different so the scale didn't really end up giving me the precision I was hoping for. I think you can get pretty good precision using identical translucent plastic containers and a block of wood or straight edge behind them as a reference point. > Having spent quite a few years in R&D which involved formulating a variety of potions and substances, including epoxy adhesive systems, I should point out something for informative purposes. The one major problem with your "discovery", is that volume ratios are not the gospel. Mass ratios are. Mixing by proper mass ratio is required to achieve a stoichiometric balance between the two components. Volume ratio takes second chair to mixing in the proper ratio of mass. Epoxies such as T-88 are formulated so that you can achieve a reasonably accurate A:B blend when mixing by volume, which is what most people leans towards as it is convenient and does not require a scale or balance to do so. If you are off a bit on either side of ideal the properties are not adversely affected, but there are limits to that. You will note the caution on the data sheet regardng addition of extra hardener for example - that is a complete no-no. In the world of epoxies and curatives, and in other adhesive chemistries as well, the raw material data contains a figure known as "equivalent weight" - which in simple terms is the mass (= weight on a scale) of one material that contains a known amount of reactive sites on the molecule. In order for each "A" site to react with a matching "B" site on the curative, you need an equal number of reactive sites on each side. When you have the equivalent weights of the materials, this is easy, and the two are mixed in proportion according to the equivalent weights, giving an equal number of "A" and "B" parts. Volume is in fact completely irrelevant and no more than a secondary parameter, and is only accounted for in the formulation and provided as a convenient method of mixing. Yes to one possible burning question: if the specific gravities of two materials are known, you can theoretically mix them correctly by volume. However, think of the things that could throw you off: (1) air bubbles in either material (2) tapered weighing vessels (3) human error (4) misreading due to the meniscus (the curve at the side of some liquid materials) (5) material stuck to the side of the weighing vessel (6) a combination of any of the above or other issues not listed None of which apply when mixing by weight! Don't be fooled by the manufacturer's listed 1:1 ratio by volume - there is a bag of tricks available to the formulator to allow them to adjust each side so that 1:1 volume gives the right mix ratio. However, they do this with prior knowledge of the correct mass ratios. A good rule to follow is, anytime you have access to two things - (1) a reasonably accurate scale, and (b) the A:B mass ratio specified by the manufacturer of the epoxy system - you should mix by mass versus by volume. In the long run your mixes will be more consistent and therefore by inference will be closer to the maximum properties of the adhesive system. In essence, you can bypass the secondary method of volume mixing and it's potential flwas, and go right to the horse's mouth by using a scale. In simple terms, while volumetric mixing is "good enough" in most cases, when you have the choice, would you not err towards the knowledge that you have not made a volume interpretation error and use the mass ratios instead? To me I can't do something in a less accurate manner when the better way is available and has far fewer caveats. For the cost of a scale good enough to do the job, which can be measured in tens of dollars and is therefore insignificant compared to the investment in time and money on a homebuilt, why piddle around? Hey, just my "$0.02".. [Wink] Mike D. -------- Piet-builder-who-hopes-to-be-flying-next-summer Read this topic online here: http://forums.matronics.com/viewtopic.php?p=150169#150169 ________________________________ Message 17 ____________________________________ Time: 11:35:20 AM PST US Subject: RE: Pietenpol-List: Re: Vi Kaplers hinges From: "Jack T. Textor" Ryan, I'm not sure who that was. If it was the fellow selling laser cut parts I believe many of the items he had were cut from stock that was to thin. Jack www.textors.com ________________________________ Message 18 ____________________________________ Time: 02:30:12 PM PST US From: "Patrick Panzera" Subject: RE: Pietenpol-List: Assembly milestone Beautiful job Dan, thanks for sharing. Gang, In the current issue of CONTACT! Magazine, our very own Oscar Zuniga presented an entertaining and well received article that explores the idea of building a Henderson Longster as a part 103 legal ultralight. Although our magazine usually doesn't delve into ultralights, I received a lot of mail asking for more "low and slow" and antique style aircraft, like what we use to get in To Fly. So with that, and motivated by Dan's inspirational photos, I'd like to ask the group to help me put together several Pietenpol articles that might help to showcase the gambit of creativity and craftsmanship spread throughout this community. I'm sure if I ask nicely, OZ can help spearhead this effort, and with that, maybe we can expand the scope of CONTACT! to include a regular presentation representing open cockpits and flying wires. I would most likely want to feature a minimum of three-four aircraft/projects. Unlike most magazines that think featuring something incomplete is taboo, we feel that our readers break down to the kind of "mechanics" (for a lack of a better word) that would love nothing more than spending an afternoon in a fellow builder's hanger, proposing over the work in progress. but I digress. I'd like to feature a 100% bone stock version of something that could have easily been hand-crafted by Bernard himself, back in the 30's. Of course since he pioneered the Corvair for use in experimental aviation, I'd like to see a Corvair powered version too. I'd also like to feature the most outrageous version available, maybe something with a turbo Sube, constant speed prop, glass cockpit, what ever. a "modern" version if you will. And then I'd like to feature something middle of the road; kinda like what Bernard would design/build today (and still be an Aircamper). hydraulic brakes, transponder, liberal use of composites or other modern materials, etc. or something that represents the current builder that's not 100% concerned about keeping to the plans. Thanks!!! Pat Panzera Editor@ContactMagazine.com _____ From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of HelsperSew@aol.com Sent: Saturday, December 01, 2007 10:41 AM Subject: Pietenpol-List: Assembly milestone Guys, I have reached a milestone today. I was finally able to bring down my one-piece wing from the wall and assemble it to the fuselage. Boy does it feel good. Here are some pics to spur on the others behind me. Dan Helsper Poplar Grove, IL. ________________________________ Message 19 ____________________________________ Time: 08:39:53 PM PST US From: "gcardinal" Subject: Re: Pietenpol-List: Assembly milestone Hi Pat, I will forward this request to Greg Bacon. Greg is the current owner of Mountain Piet, the turbo-Subaru powered Piet that is undergoing a wing reconstruction after a landing mishap. Greg Cardinal ----- Original Message ----- From: Patrick Panzera To: pietenpol-list@matronics.com Sent: Monday, December 03, 2007 4:27 PM Subject: RE: Pietenpol-List: Assembly milestone Beautiful job Dan, thanks for sharing. Gang, In the current issue of CONTACT! Magazine, our very own Oscar Zuniga presented an entertaining and well received article that explores the idea of building a Henderson Longster as a part 103 legal ultralight. Although our magazine usually doesn't delve into ultralights, I received a lot of mail asking for more "low and slow" and antique style aircraft, like what we use to get in To Fly. So with that, and motivated by Dan's inspirational photos, I'd like to ask the group to help me put together several Pietenpol articles that might help to showcase the gambit of creativity and craftsmanship spread throughout this community. I'm sure if I ask nicely, OZ can help spearhead this effort, and with that, maybe we can expand the scope of CONTACT! to include a regular presentation representing open cockpits and flying wires. I would most likely want to feature a minimum of three-four aircraft/projects. Unlike most magazines that think featuring something incomplete is taboo, we feel that our readers break down to the kind of "mechanics" (for a lack of a better word) that would love nothing more than spending an afternoon in a fellow builder's hanger, proposing over the work in progress. but I digress. I'd like to feature a 100% bone stock version of something that could have easily been hand-crafted by Bernard himself, back in the 30's. Of course since he pioneered the Corvair for use in experimental aviation, I'd like to see a Corvair powered version too. I'd also like to feature the most outrageous version available, maybe something with a turbo Sube, constant speed prop, glass cockpit, what ever. a "modern" version if you will. And then I'd like to feature something middle of the road; kinda like what Bernard would design/build today (and still be an Aircamper). hydraulic brakes, transponder, liberal use of composites or other modern materials, etc. or something that represents the current builder that's not 100% concerned about keeping to the plans. Thanks!!! Pat Panzera Editor@ContactMagazine.com ------------------------------------------------------------------------- ----- From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of HelsperSew@aol.com Sent: Saturday, December 01, 2007 10:41 AM To: pietenpol-list@matronics.com Subject: Pietenpol-List: Assembly milestone Guys, I have reached a milestone today. I was finally able to bring down my one-piece wing from the wall and assemble it to the fuselage. Boy does it feel good. Here are some pics to spur on the others behind me. Dan Helsper Poplar Grove, IL. ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message pietenpol-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Pietenpol-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/pietenpol-list Browse Digests http://www.matronics.com/digest/pietenpol-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.