Today's Message Index:
----------------------
1. 12:14 AM - Re: Composites and mold work (WurlyBird)
2. 02:53 AM - Re: Kitfox-List Digest: 8 Msgs - 01/22/11 (great bear)
3. 03:48 AM - Re: Re: Composites and mold work (Lynn Matteson)
4. 06:37 AM - Re: Re: Composites and mold work (Lynn Matteson)
5. 06:49 AM - Re: Re: Composites and mold work (Noel Loveys)
6. 07:03 AM - Re: Re: Composites and mold work (Noel Loveys)
7. 07:27 AM - Re: Re: Composites and mold work (Lynn Matteson)
8. 08:39 AM - Re: Composites and mold work (Guy Buchanan)
9. 09:03 AM - Re: Re: Composites and mold work (Patrick Reilly)
10. 10:10 AM - Re: Re: Composites and mold work (Lynn Matteson)
11. 10:17 AM - Re: Re: Composites and mold work (Michael Logan)
12. 10:25 AM - Re: Composites and mold work (Lynn Matteson)
13. 02:55 PM - Re: Kitfox-List Digest: 8 Msgs - 01/22/11 (EMAproducts@aol.com)
14. 03:35 PM - Re: Re: Composites and mold work (Noel Loveys)
15. 04:13 PM - Re: Re: Composites and mold work (Noel Loveys)
16. 04:51 PM - Re: bleed problem (jridgway)
17. 06:48 PM - Re: Re: Composites and mold work (Lynn Matteson)
18. 08:22 PM - 582 throttle cable (369PL)
19. 09:04 PM - Re: Re: Kitfox-List Digest: 8 Msgs - 01/22/11 (Lowell Fitt)
Message 1
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| Subject: | Re: Composites and mold work |
Good point Guy, I completely forgot to mention the TOOL factor (not me, the actual
tools). I am always collecting more tools, it drives my wife crazy. I always
claim I can build something for less then it can be bought, of course I never
factor in all the tools I don't yet have to that cost. One day though, I
will have all the tools I need :D
--------
James
Kitfox 3 / 582 / 70" IVO 2 blade GA
50 hrs on the Fox in between deployments,
now she lies in wait
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=327979#327979
Message 2
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| Subject: | Re: Kitfox-List Digest: 8 Msgs - 01/22/11 |
A followup on vacuum bagging and heating fiberglassfor curing...There is a lot
of structural work in building a Glasair...I never vacuum bagged any
part...everything was hand layed two or three layers at a time...as long as the
room temps was close to 60- 70 degrees the glass would cure to sandable over
night so there was no need to heat anything if ambient was close to that
range....most builders (including myself) would wait for a cool day ( 45-50) to
layup big stuff like the wing spars and major assemblies so that the working
time and pot life would be long enough to make adjustments, but keep in mind the
cure time would be days for those parts under those conditions but the bond
would be just as strong..and heat the room...not the parts if you must...it
seems like there is many approaches to this subject but I definitely agree that
vacuum bagging parts is a waste of material and time for the projects we are
doing...if you were building one of rutans space planes or 50 foot windmill
props I could see a reason....but fuel tanks and speedcuffs, cowling..little
fairings....not worth the time and extra material..west epoxy is almost clear so
it works great if your going to leave parts natural..best stuff I have used so
far...I didnt start out with that system but once I found out about it I wouldnt
recommend anything else so far.......Gary ..,,,,,KF5 Outback.0-200 at
80%....Glasair 1TD flying... and Cessna 170A (My daily driver)
Message 3
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| Subject: | Re: Composites and mold work |
OK, if the part being built is a flat instrument panel, then no bag
is required. Just lay out your shape on a plate of glass. The glass
side will be the outside of the panel. You probably won't even have
to wax it. By the way, I bought and used the mold release wax, and
the spray-on release compound, and they both work fine, but so did
the Johnson's Paste Wax that I have used prior to buying the
"professional mold releases"...and a lot cheaper, too. A friend of
mine made a very nice clip board using carbon fiber which he laid out
on glass and it came out looking super...very smooth, because he
squeeged the excess resin off the layup, and used the glass side as
the front surface....a sheet of nylon or plastic works too.
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062
Sensenich 62"x 55.5 Wood (winter) until the Prince prop arrives
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying...1078+ hrs (since 3-27-2006)
On Jan 22, 2011, at 2:23 PM, WurlyBird wrote:
> <james.t.trizzino@us.army.mil>
>
>
> Lynn Matteson wrote:
>> see if you really need to "bag
>> it" or if it just sounds like a really cool thing to do....like I
>> did. : )
>
>
> C'mon, we are talking about not structural parts for a Kitfox. It
> is not necessary to use composites at all much less vacuum
> bagging. It is definitely because it sounds like the cool thing to
> do. :D I have a tendency to have visions of grandeur with my
> projects, especially sitting here in a crappy country dreaming
> about it for a year! I have been interested in vacuum bagging for
> as long as I have understood what composites are good for. I keep
> adding to my "wish list" at Aircraft Spruce and it certainly costs
> noticeably more to bag anything. I am also trying to figure out
> how much I will actually use the system as it is only NEEDED for
> one idea I have right now and all I have come up with besides
> making the occasional part is using it to instantly marinate
> meats. I can hear it now;
>
> friend- "What is James doing in the garage?"
> wife- "Marinating the chicken."
> now confused friend- "With an air compressor?!?!"
>
> [Shocked]
>
> --------
> James
> Kitfox 3 / 582 / 70" IVO 2 blade GA
> 50 hrs on the Fox in between deployments,
> now she lies in wait
Message 4
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| Subject: | Re: Composites and mold work |
I can NEVER pass up a new tool...especially if it's high on the "cool
tool" barometer. : ) Hell, I've got some cool tools that are so
beyond my personal (used once) usage, that I have to use them on my
CFI' s airplanes just to *justify* their purchase.
By the way, when I was waiting for the air compressor-powered vacuum
bagging kit to arrive, I made do with a vacuum cleaner just to run a
test sample of bagging. It worked, but who wants to listen to the
vacuum cleaner run for hours...certainly not the dog! : )
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062
Sensenich 62"x 55.5 Wood (winter) until the Prince prop arrives
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying...1078+ hrs (since 3-27-2006)
do not archive
On Jan 22, 2011, at 11:48 PM, Guy Buchanan wrote:
>
> On 1/22/2011 9:59 AM, Lynn Matteson wrote:
>> By the way, I bought my kit when I was thinking of using it to
>> make a pair of skis, then went in another direction. I will finish
>> the vacuum pump one of these days, and then actually use it, but
>> the cost of the supplies that are scrapped during its use should
>> justify the use. If you can make the part light without bagging,
>> that part will be a lot cheaper.
>
> HAHAHAHAHA! C'mon Lynn. When did ANYTHING in aviation get justified
> on a cost basis. We do it because it's COOL. Way COOL. (Besides,
> who can pass up an opportunity to get more tools.)
>
> Guy Buchanan
> Ramona, CA
> Kitfox IV-1200 / 592-C / Warp 3cs / 500 hrs. and grounded
>
>
Message 5
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| Subject: | Re: Composites and mold work |
Most if not all commercial parts are cured in an autoclave. They use vacuum
inside the bagging and pressure outside with of course heat. The heat is
required to make the Layup cloths cure. Without the heat the cloth can
actually never properly cure.
Noel
-----Original Message-----
From: owner-kitfox-list-server@matronics.com
[mailto:owner-kitfox-list-server@matronics.com] On Behalf Of Guy Buchanan
Sent: January 22, 2011 12:28 PM
Subject: Re: Kitfox-List: Re: Composites and mold work
On 1/21/2011 9:51 PM, WurlyBird wrote:
> Does heating the resin while it is curing cause it to more thoroughly
cure? From the way you phrased it it sounds like if you expect your part to
be exposed to 200 deg in use then it should be baked at a minimum of 200 deg
during build up, is this about right?
Perfect.
> Joe Woodworker has designed and has free plans for venturi style vacuum
press and vennersupplies sells the kit. This set up has the benefit of
having a vacuum reservoir that can easily be made a little larger and even
as published should be great for dash sized projects.
>
I did the verturi thing once and it required an ENORMOUS amount of air
which I didn't have. I got a surplus vacuum pump instead.
Guy Buchanan
Ramona, CA
Kitfox IV-1200 / 592-C / Warp 3cs / 500 hrs. and grounded
Message 6
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| Subject: | Re: Composites and mold work |
Vacuum bagging results in very strong light parts when done properly. There
is another problem with bagging and that is the possibility of voids inside
the part which you can only find with ultrasound or industrial X-ray. Even
the commercial composite companies spend a lot of time checking each and
every part they make looking for weaknesses and voids.
For repair work there is a machine available, called a Hot Shot, which comes
in a suitcase. It has hoses, sniffers and a heat blanket in the case to
cure Pre-Preg cloth. Don't ask how much!
Noel
-----Original Message-----
From: owner-kitfox-list-server@matronics.com
[mailto:owner-kitfox-list-server@matronics.com] On Behalf Of Lynn Matteson
Sent: January 22, 2011 2:29 PM
Subject: Re: Kitfox-List: Re: Composites and mold work
I bought the air compressor-powered vacuum bagging kit and have yet
to finish the completion of the pump. I got mine over a year ago,
after seeing one that a friend built from one of He likes the way it
works, but cautioned me that using the bagging system....any bagging
system....is very costly in materials. He said that the raw materials
used up and thrown away counts up, and he found that he doesn't use
his bagging method as much since he discovered that. Just be aware of
the cost of doing vacuum bagging, and see if you really need to "bag
it" or if it just sounds like a really cool thing to do....like I
did. : )
By the way, I bought my kit when I was thinking of using it to make a
pair of skis, then went in another direction. I will finish the
vacuum pump one of these days, and then actually use it, but the
cost of the supplies that are scrapped during its use should justify
the use. If you can make the part light without bagging, that part
will be a lot cheaper.
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062
Sensenich 62"x 55.5 Wood (winter) until the Prince prop arrives
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying...1078+ hrs (since 3-27-2006)
On Jan 22, 2011, at 12:51 AM, WurlyBird wrote:
> <james.t.trizzino@us.army.mil>
>
> Thanks for the great information. Here is the first followup
> question.
>
> What does baking a composite part do to the build up?
>
> Does heating the resin while it is curing cause it to more
> thoroughly cure? From the way you phrased it it sounds like if you
> expect your part to be exposed to 200 deg in use then it should be
> baked at a minimum of 200 deg during build up, is this about right?
>
> I do plan on leaving some of the parts natural. If I get the HKS
> when I get home I am going to need a new instrument panel and I
> figure it might as well be carbon or carbon/kevlar. Light,
> functional, and sexy, you cant beat it. With the Kitfox being as
> low tech and old school as it is, I anticipate that the carbon on
> the dash will look a little out of place so there will need to be a
> little carbon here and a little there just to balance it out
> aesthetically. I am conceiving a part that will be a LOT of sharp
> corners but I plan on getting into bagging and maybe even
> infusion. If the part I have in my head works out I will be
> telling you all about it, until then it is hush hush.
>
> In case anyone else has been toying with the idea of bagging but
> can not find a reasonable set up, check this out:
>
> http://www.veneersupplies.com/
> http://www.joewoodworker.com/
>
> Joe Woodworker has designed and has free plans for venturi style
> vacuum press and vennersupplies sells the kit. This set up has the
> benefit of having a vacuum reservoir that can easily be made a
> little larger and even as published should be great for dash sized
> projects.
>
> --------
> James
> Kitfox 3 / 582 / 70" IVO 2 blade GA
> 50 hrs on the Fox in between deployments,
> now she lies in wait
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=327856#327856
>
>
Message 7
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| Subject: | Re: Composites and mold work |
Noel-
Using the terms "layup cloths" and "the cloth can never properly
cure" sounds like you're referring to "pre-pegs", right? I just never
figured the pre-pegs were in my league for the parts that I was
looking to make, let alone an autoclave.
By the way, the ski "spats" that I just made (to keep the snow off
the airplane's skis) were laid up over Poly-fiber fabric, which was
painted with a spray can (just to seal the weave of the fabric, waxed
with mold release wax, then sprayed with PVA release film. I applied
the Polyfiber fabric over the skis, tightened it down, painted it and
went to work with the fiberglass....e-glass, that is. Two layers of
this came out to 28-32 thousandths thick, and strong. The resulting
spats weigh about 20 ounces each. I just wish the skis were
relatively light as well....that'll come next.
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062
Sensenich 62"x 55.5 Wood (winter) until the Prince prop arrives
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying...1078+ hrs (since 3-27-2006)
On Jan 23, 2011, at 9:39 AM, Noel Loveys wrote:
>
> Most if not all commercial parts are cured in an autoclave. They
> use vacuum
> inside the bagging and pressure outside with of course heat. The
> heat is
> required to make the Layup cloths cure. Without the heat the cloth
> can
> actually never properly cure.
>
> Noel
>
> -----Original Message-----
> From: owner-kitfox-list-server@matronics.com
> [mailto:owner-kitfox-list-server@matronics.com] On Behalf Of Guy
> Buchanan
> Sent: January 22, 2011 12:28 PM
> To: kitfox-list@matronics.com
> Subject: Re: Kitfox-List: Re: Composites and mold work
>
>
> On 1/21/2011 9:51 PM, WurlyBird wrote:
>> Does heating the resin while it is curing cause it to more thoroughly
> cure? From the way you phrased it it sounds like if you expect
> your part to
> be exposed to 200 deg in use then it should be baked at a minimum
> of 200 deg
> during build up, is this about right?
> Perfect.
>> Joe Woodworker has designed and has free plans for venturi style
>> vacuum
> press and vennersupplies sells the kit. This set up has the
> benefit of
> having a vacuum reservoir that can easily be made a little larger
> and even
> as published should be great for dash sized projects.
>>
> I did the verturi thing once and it required an ENORMOUS amount of air
> which I didn't have. I got a surplus vacuum pump instead.
>
> Guy Buchanan
> Ramona, CA
> Kitfox IV-1200 / 592-C / Warp 3cs / 500 hrs. and grounded
>
>
Message 8
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| Subject: | Re: Composites and mold work |
On 1/23/2011 2:51 AM, great bear wrote:
> I definitely agree that
> vacuum bagging parts is a waste of material and time for the projects we are
> doing...if you were building one of rutans space planes or 50 foot windmill
> props I could see a reason....but fuel tanks and speedcuffs, cowling..little
> fairings....not worth the time and extra material..
Hi. Would you please put your full name, location and aircraft type /
status in your signature line? We, the moderators, find it makes for a
much more congenial atmosphere. Thanks.
Regarding vacuum bagging. It is far more expensive but I recommended it
based on a suggestion of sharp corners in the part. There's no way to
get female corners sharp in a contact laminate, and male corners are
deucedly hard. (Though it can be done with some crude tooling.) Glasairs
and Lancairs and most other composite kit aircraft were designed very
carefully to avoid vacuum bagging, with all the sharp corners in the
provided kit parts.
Guy Buchanan - List moderator
Ramona, CA
Kitfox IV-1200 / 592-C / Warp 3cs / 500 hrs. and grounded
Message 9
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| Subject: | Re: Composites and mold work |
James, The problem is once you have that many tools you either can't find
them or can't remember if you have a specific tool. Hell, I got divorced 11
years ago, and sold virtually all my tools at that time. In the last 6 years
I once again have accumulated a hanger and a garage full of tools, often
duplicated because if I need it at home the tool is at the hanger and visa
versa. By the way has anybody got an auto lift for sale. When I buy the
hanger next to mine I have it figured out how I can install it and still get
2 planes in. I have a stick welder, wire welder and acyletlene set up.
But, I still need a TIG unit if you have one you aren't using.....HA It's
an addiction! But, I have been able to resist ever buying vaccume bagging
equipment. And researching what vaccume bagging takes, I'll stick with West
System products and hand layup.
Pat Reilly
Mod 3 582 Rebuilt
Rockford, IL
On Sun, Jan 23, 2011 at 2:12 AM, WurlyBird <james.t.trizzino@us.army.mil>wrote:
> james.t.trizzino@us.army.mil>
>
> Good point Guy, I completely forgot to mention the TOOL factor (not me, the
> actual tools). I am always collecting more tools, it drives my wife crazy.
> I always claim I can build something for less then it can be bought, of
> course I never factor in all the tools I don't yet have to that cost. One
> day though, I will have all the tools I need :D
>
> --------
> James
> Kitfox 3 / 582 / 70" IVO 2 blade GA
> 50 hrs on the Fox in between deployments,
> now she lies in wait
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=327979#327979
>
>
--
Pat Reilly
Mod 3 582 Rebuild
Rockford,IL
Message 10
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| Subject: | Re: Composites and mold work |
The West System 5:1 pumps are great, too...IF that's what the ratio
needs to be....but I use a way to make less than the 1-ounce of mix
that one stroke of the pumps puts out. It's no big deal, but if you
need, say, a partial ounce to finish up a job, or just a small job
that will need less than an ounce, just use two equal-size cups on
the balance scales...one on each side...and put a 10-32 nut in one
cup and *carefully* pump hardener until the scales balance again.
Then add 5 nuts of the same size and pump the resin until the scales
balance again...simple math/physics, and you've cheated the waste
basket of some otherwise wasted epoxy.
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062
Sensenich 62"x 55.5 Wood (winter) until the Prince prop arrives
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying...1078+ hrs (since 3-27-2006)
On Jan 23, 2011, at 11:54 AM, Patrick Reilly wrote:
> James, The problem is once you have that many tools you either
> can't find them or can't remember if you have a specific tool.
> Hell, I got divorced 11 years ago, and sold virtually all my tools
> at that time. In the last 6 years I once again have accumulated a
> hanger and a garage full of tools, often duplicated because if I
> need it at home the tool is at the hanger and visa versa. By the
> way has anybody got an auto lift for sale. When I buy the hanger
> next to mine I have it figured out how I can install it and still
> get 2 planes in. I have a stick welder, wire welder and acyletlene
> set up. But, I still need a TIG unit if you have one you aren't
> using.....HA It's an addiction! But, I have been able to resist
> ever buying vaccume bagging equipment. And researching what vaccume
> bagging takes, I'll stick with West System products and hand layup.
>
> Pat Reilly
> Mod 3 582 Rebuilt
> Rockford, IL
>
Message 11
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| Subject: | Re: Composites and mold work |
Chrissi and Randi of the Cozy Girrrls
(http://www.cozygirrrl.com/menupage.htm) have developed a low cost vacuum
bagging process that is pretty cool and does not cost much in wasted
materials. I watched them makes some pieces at Sun-n-Fun last year and it
really works.
Mike Logan
Series 5 RAM EA81
-----Original Message-----
From: owner-kitfox-list-server@matronics.com
[mailto:owner-kitfox-list-server@matronics.com] On Behalf Of Guy Buchanan
Sent: Saturday, January 22, 2011 11:49 PM
Subject: Re: Kitfox-List: Re: Composites and mold work
On 1/22/2011 9:59 AM, Lynn Matteson wrote:
> By the way, I bought my kit when I was thinking of using it to make a
> pair of skis, then went in another direction. I will finish the vacuum
> pump one of these days, and then actually use it, but the cost of the
> supplies that are scrapped during its use should justify the use. If
> you can make the part light without bagging, that part will be a lot
> cheaper.
HAHAHAHAHA! C'mon Lynn. When did ANYTHING in aviation get justified on a
cost basis. We do it because it's COOL. Way COOL. (Besides, who can pass
up an opportunity to get more tools.)
Guy Buchanan
Ramona, CA
Kitfox IV-1200 / 592-C / Warp 3cs / 500 hrs. and grounded
Message 12
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| Subject: | Re: Composites and mold work |
I made a slight mistake in buying a DVD of a fiberglass project that
some students were doing. One of the best points that I took away
from viewing this DVD was that the *most* important element of
building a mold, or making a product, was the design of the product/
mold. You cannot have negative draft and expect to get the part out
of a one-piece mold. These guys were trying to get a spherical-shaped
part out of a mold, and later realized that the mold must be split at
the widest part of the part, thus eliminating any negative draft in
either of the two parts of the mold. Maybe the male/female corners
could be done this way, eh?
I was taught in Fiberglass 101 (actually an EAA weekend course) to
make up a slurry of resin and filler (filler type depending on the
application) to use in sharp corners....sometimes after the part was
laid up and cured.
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062
Sensenich 62"x 55.5 Wood (winter) until the Prince prop arrives
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying...1078+ hrs (since 3-27-2006)
On Jan 23, 2011, at 11:21 AM, Guy Buchanan wrote:
>
> On 1/23/2011 2:51 AM, great bear wrote:
>> I definitely agree that
>> vacuum bagging parts is a waste of material and time for the
>> projects we are
>> doing...if you were building one of rutans space planes or 50 foot
>> windmill
>> props I could see a reason....but fuel tanks and speedcuffs,
>> cowling..little
>> fairings....not worth the time and extra material..
> Hi. Would you please put your full name, location and aircraft
> type / status in your signature line? We, the moderators, find it
> makes for a much more congenial atmosphere. Thanks.
>
> Regarding vacuum bagging. It is far more expensive but I
> recommended it based on a suggestion of sharp corners in the part.
> There's no way to get female corners sharp in a contact laminate,
> and male corners are deucedly hard. (Though it can be done with
> some crude tooling.) Glasairs and Lancairs and most other composite
> kit aircraft were designed very carefully to avoid vacuum bagging,
> with all the sharp corners in the provided kit parts.
>
> Guy Buchanan - List moderator
> Ramona, CA
> Kitfox IV-1200 / 592-C / Warp 3cs / 500 hrs. and grounded
>
>
Message 13
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| Subject: | Re: Kitfox-List Digest: 8 Msgs - 01/22/11 |
Subject: Re: Kitfox-List: Re: Composites and mold work
About 20 years I was doing some composite work and looking for a low cost
vacuum pump. An old auto air conditioner compressor with a electric motor
to turn it, hook to the inlet line with a gauge & relief valve and your
vacuum is limited to the size of the electric motor driving it! I made lots
of NASA inlets using it. has been over 30 years don't remember vacuum or
anything else.
Message 14
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| Subject: | Re: Composites and mold work |
You're right Lynn. However not all resins will cure at room temperature.
The same resins in Pre-preg are available for wet layup. They will require
heat even if applied locally to cure properly. When filling cloth with
resin for the greatest strength and least weight there is a ratio of cloth
to resin by weight which should not be exceeded. Because the stiffness is
caused by the resin and the strength is actually in the cloth too much resin
or too little resin makes for a weaker part.
The process I use is to fill my cloth with resin. I generally weigh the
cloth and the mixed resins. Then I sandwich the cloth in clear plastic and
squeegee out any excess resin. (usually not very much) Then I can put the
cloth "sandwich" rolled up in a refrigerator while making more "sandwiches".
When I have all the cloth I think I'll need in the sandwich from (plastic on
both sides) I then start my lay up... rolling each layer of cloth into the
previous layer. Doing it that way more or less insures me of two things...
an efficient amount of resin in the final product and I can easily see voids
as I do the layup and roll them out.
When we trained in composites we generally used uni-directional cloth but we
also followed a bagging schedule which laid out the direction the warp of
each layer ran. Some bagging schedules had many layers of cloth. Following
the schedule religiously ensured good strength in all directions. You would
be amazed at the strength of a piece of composite glass or graphite two
inches long and 1/8 in thick(in both directions)
There is a problem with vacuum bagged composites which comes up from time to
time. That is it is porous. A small insignificant nick in the finish of say
a 777 cowl can be very dangerous as rain water can seep into the material
through a scratch. At altitude the water freezes and the cowl can be
internally forced apart by the expansion of the freezing water. A slight
rub by a forklift brushing an aluminium cowl may not be of any concern. The
same damage to a composite will ground the aircraft until the cowl is
replaced.... bring MONEY!
The crown who were specializing in composite repair (not me) used to make
forms to mould on. Those Forms (plugs) were made of straw wet with some
kind of plaster for the rough shape then finished with plaster of paris
which can be sanded to final shape and then waxed.
Noel
-----Original Message-----
From: owner-kitfox-list-server@matronics.com
[mailto:owner-kitfox-list-server@matronics.com] On Behalf Of Lynn Matteson
Sent: January 23, 2011 11:50 AM
Subject: Re: Kitfox-List: Re: Composites and mold work
Noel-
Using the terms "layup cloths" and "the cloth can never properly
cure" sounds like you're referring to "pre-pegs", right? I just never
figured the pre-pegs were in my league for the parts that I was
looking to make, let alone an autoclave.
By the way, the ski "spats" that I just made (to keep the snow off
the airplane's skis) were laid up over Poly-fiber fabric, which was
painted with a spray can (just to seal the weave of the fabric, waxed
with mold release wax, then sprayed with PVA release film. I applied
the Polyfiber fabric over the skis, tightened it down, painted it and
went to work with the fiberglass....e-glass, that is. Two layers of
this came out to 28-32 thousandths thick, and strong. The resulting
spats weigh about 20 ounces each. I just wish the skis were
relatively light as well....that'll come next.
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062
Sensenich 62"x 55.5 Wood (winter) until the Prince prop arrives
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying...1078+ hrs (since 3-27-2006)
On Jan 23, 2011, at 9:39 AM, Noel Loveys wrote:
>
> Most if not all commercial parts are cured in an autoclave. They
> use vacuum
> inside the bagging and pressure outside with of course heat. The
> heat is
> required to make the Layup cloths cure. Without the heat the cloth
> can
> actually never properly cure.
>
> Noel
>
> -----Original Message-----
> From: owner-kitfox-list-server@matronics.com
> [mailto:owner-kitfox-list-server@matronics.com] On Behalf Of Guy
> Buchanan
> Sent: January 22, 2011 12:28 PM
> To: kitfox-list@matronics.com
> Subject: Re: Kitfox-List: Re: Composites and mold work
>
>
> On 1/21/2011 9:51 PM, WurlyBird wrote:
>> Does heating the resin while it is curing cause it to more thoroughly
> cure? From the way you phrased it it sounds like if you expect
> your part to
> be exposed to 200 deg in use then it should be baked at a minimum
> of 200 deg
> during build up, is this about right?
> Perfect.
>> Joe Woodworker has designed and has free plans for venturi style
>> vacuum
> press and vennersupplies sells the kit. This set up has the
> benefit of
> having a vacuum reservoir that can easily be made a little larger
> and even
> as published should be great for dash sized projects.
>>
> I did the verturi thing once and it required an ENORMOUS amount of air
> which I didn't have. I got a surplus vacuum pump instead.
>
> Guy Buchanan
> Ramona, CA
> Kitfox IV-1200 / 592-C / Warp 3cs / 500 hrs. and grounded
>
>
Message 15
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| Subject: | Re: Composites and mold work |
I gotta love that idea!
Noel
-----Original Message-----
From: owner-kitfox-list-server@matronics.com
[mailto:owner-kitfox-list-server@matronics.com] On Behalf Of Lynn Matteson
Sent: January 23, 2011 2:38 PM
Subject: Re: Kitfox-List: Re: Composites and mold work
The West System 5:1 pumps are great, too...IF that's what the ratio
needs to be....but I use a way to make less than the 1-ounce of mix
that one stroke of the pumps puts out. It's no big deal, but if you
need, say, a partial ounce to finish up a job, or just a small job
that will need less than an ounce, just use two equal-size cups on
the balance scales...one on each side...and put a 10-32 nut in one
cup and *carefully* pump hardener until the scales balance again.
Then add 5 nuts of the same size and pump the resin until the scales
balance again...simple math/physics, and you've cheated the waste
basket of some otherwise wasted epoxy.
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062
Sensenich 62"x 55.5 Wood (winter) until the Prince prop arrives
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying...1078+ hrs (since 3-27-2006)
On Jan 23, 2011, at 11:54 AM, Patrick Reilly wrote:
> James, The problem is once you have that many tools you either
> can't find them or can't remember if you have a specific tool.
> Hell, I got divorced 11 years ago, and sold virtually all my tools
> at that time. In the last 6 years I once again have accumulated a
> hanger and a garage full of tools, often duplicated because if I
> need it at home the tool is at the hanger and visa versa. By the
> way has anybody got an auto lift for sale. When I buy the hanger
> next to mine I have it figured out how I can install it and still
> get 2 planes in. I have a stick welder, wire welder and acyletlene
> set up. But, I still need a TIG unit if you have one you aren't
> using.....HA It's an addiction! But, I have been able to resist
> ever buying vaccume bagging equipment. And researching what vaccume
> bagging takes, I'll stick with West System products and hand layup.
>
> Pat Reilly
> Mod 3 582 Rebuilt
> Rockford, IL
>
Message 16
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| Subject: | Re: bleed problem |
GOOD LUCK...jack
I FOUND THE MATCO FOLKS VERY HELPFUL.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=328119#328119
Message 17
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| Subject: | Re: Composites and mold work |
I bought the publication "Moldless Composite Sandwich Aircraft
Construction" by the Rutan Aircraft Factory, and in it there is an
exercise where you make three different pads of fiberglass, each one
to measure 8" x 8". You make one too wet, one too dry and one "just
right", by squeegeeing with many light strokes. After curing, each is
cut to a size of 7" x 7", then weighed and compared. They say the
correct weight should be 2.25 ounces. If the heavy one weighs 2.55
ounces, it will add 35 pounds to the finished VariEze, if this heavy
construction is used throughout the building of the plane. I'm sure
we can guess what happens if the light method is followed.
When I recently made spats for my skis, I did the 8" x 8" pads, but I
was more interested in how thick and how strong 2 plies, versus 3
plies, versus 4 plies would be. I settled on the 2 plies for my
project....the 4 plies (of E-glass) would have been almost strong
enough to make the ski bottoms from....it was stiff!
I've never given any thought to the pre-pregs...how do you "kick off"
the curing activity? There must be something added to the pre-pregged
cloths, isn't there? That technology just seems a bit out of my
league. : )
I used bi-directional E-glass cloth for my spats, because I was
limited by the amount of angle that I could get by using material
that was only 50 inches wide. My method was probably not going to
meet aircraft-building standards, but I feel that it was good enough
for the task of keeping snow off my skis.
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062
Sensenich 62"x 55.5 Wood (winter) until the Prince prop arrives
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying...1080+ hrs (since 3-27-2006)
On Jan 23, 2011, at 6:29 PM, Noel Loveys wrote:
>
> You're right Lynn. However not all resins will cure at room
> temperature.
> The same resins in Pre-preg are available for wet layup. They will
> require
> heat even if applied locally to cure properly. When filling cloth
> with
> resin for the greatest strength and least weight there is a ratio
> of cloth
> to resin by weight which should not be exceeded. Because the
> stiffness is
> caused by the resin and the strength is actually in the cloth too
> much resin
> or too little resin makes for a weaker part.
>
> The process I use is to fill my cloth with resin. I generally weigh
> the
> cloth and the mixed resins. Then I sandwich the cloth in clear
> plastic and
> squeegee out any excess resin. (usually not very much) Then I can
> put the
> cloth "sandwich" rolled up in a refrigerator while making more
> "sandwiches".
> When I have all the cloth I think I'll need in the sandwich from
> (plastic on
> both sides) I then start my lay up... rolling each layer of cloth
> into the
> previous layer. Doing it that way more or less insures me of two
> things...
> an efficient amount of resin in the final product and I can easily
> see voids
> as I do the layup and roll them out.
>
> When we trained in composites we generally used uni-directional
> cloth but we
> also followed a bagging schedule which laid out the direction the
> warp of
> each layer ran. Some bagging schedules had many layers of cloth.
> Following
> the schedule religiously ensured good strength in all directions.
> You would
> be amazed at the strength of a piece of composite glass or graphite
> two
> inches long and 1/8 in thick(in both directions)
>
> There is a problem with vacuum bagged composites which comes up
> from time to
> time. That is it is porous. A small insignificant nick in the
> finish of say
> a 777 cowl can be very dangerous as rain water can seep into the
> material
> through a scratch. At altitude the water freezes and the cowl can be
> internally forced apart by the expansion of the freezing water. A
> slight
> rub by a forklift brushing an aluminium cowl may not be of any
> concern. The
> same damage to a composite will ground the aircraft until the cowl is
> replaced.... bring MONEY!
>
> The crown who were specializing in composite repair (not me) used
> to make
> forms to mould on. Those Forms (plugs) were made of straw wet with
> some
> kind of plaster for the rough shape then finished with plaster of
> paris
> which can be sanded to final shape and then waxed.
>
> Noel
Message 18
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| Subject: | 582 throttle cable |
Just had my 582 rebuilt. Was in the process of doing the Rotax breakin procedure.
Pushed throttle in for the first high rpm blast. Engine rpm dropped out. Thought
it was a major problem. Turned out cable broke at the mixer. Has anybody
else had this to happen? :(
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=328162#328162
Message 19
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| Subject: | Re: Kitfox-List Digest: 8 Msgs - 01/22/11 |
I am enjoying this discussion. It is informative and nice to see that there
are those that like trying new things and willing to share experiences.
The Lancair I spend a year and a half on was was pretty much built from
vacuum bagged skins - everything carbon fiber, except rudder. Vacuum
bagging was pretty obvious as the outer skin was slick and the inner was
covered by peel-ply. sandwiched in were foam stiffiners. We did wet
lay-ups, but it was mostly as doublers under Hysol bonded joggle joints or
fitting bulkheads. We used the squeegee between plastic mostly.
I also made gap seal cuffs in the horizontal and vertical tails of my
current Model IV project. I vacuum bagged them for the same reason the
Lancair folks did theirs - weight reduction. Also they had complex shapes
and since much of it would be on a visible surface, it was the only way to
get a really nice adaptation and surface. I figure that the cuffs plus the
electric trim tabs in both rudder and elevator added about six pounds. At
the eleven foot arm that far back, I think the vacuum bagging saved me
significant weight. I mention this because there are good reasons for
vacuum bagging on our little low tech airplanes. If you are making wing
strut fairings which will be right under the CG, probably not an issue
except for empty weight considerations, but I didn't want extra weight way
back there.
One further thought. I usually only put the bagging film on one side. I
would use a sheet of aluminum or one of the white laminated shelve boards
available from Lowes or Home Depot as the sealing tape stuck fine to that
and it didn't leak. I also found that by pulling the bagging film off with
a quick jerk, it would often separate from the tape and the tape could be
used again. for the next part. Being that I was making the gap seal cuffs
and all parts had basically the same outside dimension, the board and repeat
use of the tape saved some money.
A couple of notes regarding recent posts. My vacuum pump - for vacuum
investing for lost wax casting - was pricey even in its day. Along with the
auto air conditioner compressor, I once used a compressor out of an old
refrigerator, plumbed backward, they can suck a real vacuum. And the
refrigerator compressor has a motor attached. Also, I always mix in less
than two ounce mixes and use an electronic gram scale for proportioning.
Place the cup on the scale and zero out the cup weight and go from there. I
use a 4:1 mix so 40 grams resin equals a 50 gram mix.
Lowell
--------------------------------------------------
From: "great bear" <av8r2488@yahoo.com>
Sent: Sunday, January 23, 2011 2:51 AM
Subject: Kitfox-List: Re: Kitfox-List Digest: 8 Msgs - 01/22/11
>
> A followup on vacuum bagging and heating fiberglass for curing...There is
> a lot
> of structural work in building a Glasair...I never vacuum bagged any
> part...everything was hand layed two or three layers at a time...as long
> as the
> room temps was close to 60- 70 degrees the glass would cure to sandable
> over
> night so there was no need to heat anything if ambient was close to that
> range....most builders (including myself) would wait for a cool day (
> 45-50) to
> layup big stuff like the wing spars and major assemblies so that the
> working
> time and pot life would be long enough to make adjustments, but keep in
> mind the
> cure time would be days for those parts under those conditions but the
> bond
> would be just as strong..and heat the room...not the parts if you
> must...it
> seems like there is many approaches to this subject but I definitely agree
> that
> vacuum bagging parts is a waste of material and time for the projects we
> are
> doing...if you were building one of rutans space planes or 50 foot
> windmill
> props I could see a reason....but fuel tanks and speedcuffs,
> cowling..little
> fairings....not worth the time and extra material..west epoxy is almost
> clear so
> it works great if your going to leave parts natural..best stuff I have
> used so
> far...I didnt start out with that system but once I found out about it I
> wouldnt
> recommend anything else so far.......Gary ..,,,,,KF5 Outback.0-200 at
> 80%....Glasair 1TD flying... and Cessna 170A (My daily driver)
>
>
>
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