Which epoxy?
Jim Conlin
Between us, we'll use 50+ gallons in the next year. It's similar in
requirements to homebuilt aircraft building with wet layups, some bagging,
foam, wood, glass, carbon, etc. Concerns re mechanical properties,
temperature tolerance
Which resin can we buy in drum quantities that will suit these needs?
richar...@riley.net
wrote:
The one you don't address is pot life. I'm guessing that you're doing
BIG layups, and you'll want a long pot life?
Any epoxy you want can be had in drums. (OK, maybe not JB Weld, but
any laminating epoxy).
Look at the ProSet line from Gougeon Bros. 125 resin with their
longest cure hardner (237?) might work for you, but it needs to be
heated to reach it's ultimate strength. If you can give up working
time their 229 hardner would work for you.
Epoxycal and PTM&W also have long pot life resins in drum quants, but
I don't know their numbers off hand. Again, the longer the pot life,
the more likely you'll need a boat size oven to cure it in.
If I'm wrong and you have small layups, the same sources have faster
cure resins by the truckload.
You probably already know that 55 gal drums are extraordinarily
expensive. Count on spending at least a couple of thousand per drum.
Jim Conlin
cost.
Richard Lamb
Mechanically superior to West,
no MDAs (methyl diethel amines (??))
good wet out characteristics.
--
Richard Lamb
email: lam...@flash.net
web: http://www.flash.net/~lamb01
highflyer
Talk to the Gougeon Brothers. Their epoxy system is tops for both boats
and airplanes.
--
HighFlyer
Highflight Aviation Services
Speng Gorgon
is very popular I've been. For boats that is.
Bruce A. Frank
On Sat, 14 Apr 2001, Jim Conlin wrote:
> Some friends and I are engaged in boatbuilding projects using epoxy resin.
> Between us, we'll use 50+ gallons in the next year. It's similar in
> requirements to homebuilt aircraft building with wet layups, some bagging,
> foam, wood, glass, carbon, etc. Concerns re mechanical properties,
> temperature tolerance
>
> Which resin can we buy in drum quantities that will suit these needs?
It is hard to beat the West system, designed specifically for wood and
boat building. Check with them for advise on bonding those other
materials.
http://www.westsystem.com/
--
Bruce A. Frank, Editor "Ford 3.8L Engine and V-6 STOL
BAF...@worldnet.att.net Homebuilt Aircraft Newsletter"
| Publishing interesting material|
| on all aspects of alternative |
| engines and homebuilt aircraft.|
*------------------------------**----*
\(-o-)/ AIRCRAFT PROJECTS CO.
\___/ Manufacturing parts & pieces
/ \ for homebuilt aircraft, TIG
welding
0 0
Richard Lamb
and yes, you can laminate glass with it (done it myself).
Sure, ask West about West resins.
But there are many OTHER resins for laminating.
Try DOW chemical and ask about West resins. ;)
And for fuel tanks, there are other resins.
Like Vinal-esters?
But NOT Poly-esters!
Use the Right Stuff!
Bruce A. Frank
it (gallons, not drums) when working as a model maker. Then it was one
of the least expensive on the market.
--
NGMessinger
would be System Three. With both one gets outstanding support, a product
made with boats in mind, consistancy from batch to batch, reliability at the
margines, etc. There are cheaper epoxies which receive raves from some boat
builders but I'm inclined to think a builder gets what they pay for.
Those are my personal biases based on experience with the Long EZ I built
and the 20' gaff rigged cutter I'm building now.
I'd invite anyone with questions about epoxy use in boat building to visit
the builders forum at www.woodenboat.com .
--Norm
O Goodwin
read the manual) might be for liability reasons. The Falco guys seem to
like it, and the tests run by one of their builders claim it to be equal to
or slightly superior to T88. I have been using it on my SAL mustang and
find it to work fine, and the test blocks I've made fracture the wood just
like they should.
One of the things I like in particular is the measuring pump system. It
saves lots of time and material, without shelling out for the more expensive
devices.
"Richard Riley" <richard*NOSPAM*@riley.net> wrote in message
news:klkndto7cqk5li12b...@4ax.com...
> On Tue, 17 Apr 2001 03:37:34 GMT, Richard Lamb <lam...@flash.net>
> wrote:
>
> >Yes, West is popular the wood,
> >and yes, you can laminate glass with it (done it myself).
> >
> >Sure, ask West about West resins.
> >But there are many OTHER resins for laminating.
> >Try DOW chemical and ask about West resins. ;)
> >
> >And for fuel tanks, there are other resins.
> >Like Vinal-esters?
> >But NOT Poly-esters!
> >
> >Use the Right Stuff!
>
> WEST does a very good job on fuel tanks. They have 20 year immersion
> data. Strangely, 205 does a *tiny* bit better than 206.
>
> WEST is great (I use it all the time) but Gougeon doesn't recommend it
> for laminating primary structure, only for secondary attachments.
> That's why they have ProSet.
O Goodwin
a primary structure. I had heard that West was softer than desired for
laminate of glass, etc.
"Richard Riley" <richard*NOSPAM*@riley.net> wrote in message
news:i7krdtg76cvumfb8u...@4ax.com...
> On 18 Apr 2001 17:02:20 GMT, "O Goodwin" <ogoo...@concentric.net>
> wrote:
>
> >I wonder if the disclaimer by West (I haven't personally seen it, and I
did
> >read the manual) might be for liability reasons. The Falco guys seem to
> >like it, and the tests run by one of their builders claim it to be equal
to
> >or slightly superior to T88. I have been using it on my SAL mustang and
> >find it to work fine, and the test blocks I've made fracture the wood
just
> >like they should.
>
> Two competely different jobs. When you glue wood (or anything else)
> together they consider that a secondary attachment. In that case the
> weak point is the adhesion of the epoxy to the wood, in this case, and
> WEST does a terrific job. But when you make something out of epoxy -
> laminate glass into a spar, for example - the strength of the cured
> resin (tensile and compression) determines the strentgh of the part.
> West is actually pretty soft. Proset, and all the laminating resins
> I've worked with, are much harder, but it don't stick quite as well.
> So when the Falco guys use West to assemble parts made of wood they're
> using it for what it does best.
>
> >
> >One of the things I like in particular is the measuring pump system. It
> >saves lots of time and material, without shelling out for the more
expensive
> >devices.
>
> That's actually one of the things I DON'T like :) They're great in
> concept but the resin pumps always loose their seal after a week and
> start sucking air.
Sean trost
30gal kit = 995.00
RAKA.com
All the best.
Sean Trost
Bruce A. Frank
Richard Riley wrote:
> >
> >One of the things I like in particular is the measuring pump system. It
> >saves lots of time and material, without shelling out for the more expensive
> >devices.
>
> That's actually one of the things I DON'T like :) They're great in
> concept but the resin pumps always loose their seal after a week and
> start sucking air.
When the can pump starts to suck air, sort of looses its prime, I make a
pump into a discard jar to prime everything then make my measured pumps.
Keep the discard jar capped and aid it back to the can about once a
week(if the can lasts that long when working). When ordering I have
asked for extra pumps and received them for free. Don't know what the
standard policy is, you may have to pay for extra can pumps.
--
Bruce A. Frank
Doug Hoffman
that I used. I believe that the West epoxies have relatively
low transitions temperatures, which is okay for boats but
worrisome for airplanes. My information shows the West epoxy
has about a 120 degree F transition temperature.
But Aeropoxy has a glass transition temperature closer to
200 degrees F.
I use Aeropoxy.
-Doug
In article <qPgD6.9115$6j1.1...@news1.rdc1.ne.home.com> NGMessinger,
RobertR237
<dhof...@oakland-info.com> writes:
>
>I would worry about the glass transition temperature of any epoxy
>that I used. I believe that the West epoxies have relatively
>low transitions temperatures, which is okay for boats but
>worrisome for airplanes. My information shows the West epoxy
>has about a 120 degree F transition temperature.
>
>But Aeropoxy has a glass transition temperature closer to
>200 degrees F.
>
>I use Aeropoxy.
>
>-Doug
>
Excellent point Doug, and one which should be closely looked at before you pick
any epoxy. I will also add that each of the epoxy makers offers multiple
formulations with varying transition temperatures, working times, pot life,
wetting capabilities, peel strength, compression strength, and so on. The
important part is to learn a bit about them and make your choice according to
need, especially if you are thinking of using anything besides the one
specified by the plans or kit manufacturer.
There are quite literally hundreds of different adheasive, epoxy, and glue
formulations / products available today. They are absolutely remarkable in the
various capabilities offered but can blow your mind in trying to determine
which to use for a given application or process. I have spent many hours
digging through the spec sheets and comparisons. The result is more confusion
than anything but some knowledge is slowly sinking in.
Bob Reed
http://robertr237.virtualave.net/ (KIS Project)
KIS Cruiser in progress...2001 Oshkosh Odessy ;-) (I can hope!)
"Ladies and Gentlemen, take my advice, pull down your pants and Slide on the
Ice!"
(M.A.S.H. Sidney Freidman)
KernHend
>I would worry about the glass transition temperature of any epoxy
>that I used. I believe that the West epoxies have relatively
>low transitions temperatures, which is okay for boats but
>worrisome for airplanes. My information shows the West epoxy
>has about a 120 degree F transition temperature.
>
>But Aeropoxy has a glass transition temperature closer to
>200 degrees F.
___________________________________
Well, sir you are correct to be concerned about glass transition temperatures
(Tg) but your information is incorrect. The Heat Defection Temperature of West
System epoxy is about 123F. Tg runs about 20-25F higher than HDT and, indeed,
the Tg of West System epoxy is about 148F. But, you will never see an actual
Tg of 148F in ANY epoxy capable of having this Tg UNLESS is is cured (or post
cured) at temperatures approaching the Tg. In the case of West System epoxy
you'd have to do a post cure of about 125F for a couple of hours to hit the
148F Tg. Likewise the Aeropoxy *may* be capable of having a Tg as high as 200F
but you will NEVER get this unless you cure it at least at 180F+. It is
doubtful that polystyrene foam will take these temperatures without deformation
or otherwise irreversable effects.
One should NEVER use a high Tg epoxy unless one expects to cure (or post cure)
at elevated temperatures. While these materials may well harden at room
temperature they will never fully cure and are apt to be quite brittle without
the post cure. Furthermore, once they start to see any decent elevated
temperatures they will begin to soften before chemical crosslinking makes them
rigid again.
W. Kern Hendricks
System Three Resins, Inc.
3500 West Valley Highway, N Suite 105
Auburn, WA 98001-2436
Technical Support: 253/333-8118
Orders Only: 800/333-5514
www.systemthree.com
Doug Hoffman
Aeropoxy people describes their product as "having particularly
good flexural strengths and high heat resistance with a
R.T. cure." Are they lying to me?
Perhaps you don't sell Aeropoxy?
-Doug
In article <20010420124546...@ng-fo1.aol.com> KernHend,
KernHend
>Well now you have me confused. My specifications sheet from the
>Aeropoxy people describes their product as "having particularly
>good flexural strengths and high heat resistance with a
>R.T. cure." Are they lying to me?
>
>Perhaps you don't sell Aeropoxy?
________________________________
We don't sell Aeropoxy but it doesn't matter anyway. The rules are the rules
no matter who is doing the formulating. If the data sheets says you can get a
200F Tg with an RT cure then you are being lied to. If it says "high heat
resistance with a RT cure" then it depends on the following definitions:
What is meant by "high heat" and what is meant by "resistance".
The rule is this: You can't get a Tg too much higher than the cure temperature
and then the particular formulation has to have the capacity to develop a Tg at
or slightly above the cure temperature in order for you to get a Tg as high as
the cure temperature.
You won't get a Tg much higher than 148F for West System 105/205 whether you
post cure it at 140F or 200F since it is capacity limited to about 148F. For a
system with a Tg "capacity" of 200F you won't get a Tg much higher than the
cure temperature so long as the cure temperature is below 200F. Curing above
200F will not produce a higher Tg than 200F no matter how long or how hot you
go.
Doesn't matter much if it is Aeropoxy doing the formulating or System Three or
Gougeon Brothers (West System). This is just the way things are. Goes to the
issue of thermodynamics.
Kern
Doug Hoffman
potentially *dangerous* to use (unless you postcure at a very
high temperature). You say it will be brittle and go soft at
a relatively low temperature. Why would Aircraft Spruce sell
such a product and advertise it as good stuff for room
temperature cures?
Furthermore, ACS says Rutan Aircraft Factory (RAF) recommends its
use for all homebuilt aircraft applications.
Furthermore, ACS sells West System epoxy and says it was developed
specifically for boat construction. Also, RAF "now recommends
West for certain homebuilt aircraft applications where moisture
is an issue". Floats?
I'll stick with Aeropoxy.
RobertR237
<dhof...@oakland-info.com> writes:
>
>Good grief! If I understand what you are saying, the Aeropoxy is
>potentially *dangerous* to use (unless you postcure at a very
>high temperature). You say it will be brittle and go soft at
>a relatively low temperature. Why would Aircraft Spruce sell
>such a product and advertise it as good stuff for room
>temperature cures?
>
>Furthermore, ACS says Rutan Aircraft Factory (RAF) recommends its
>use for all homebuilt aircraft applications.
>
>Furthermore, ACS sells West System epoxy and says it was developed
>specifically for boat construction. Also, RAF "now recommends
>West for certain homebuilt aircraft applications where moisture
>is an issue". Floats?
>
>
>I'll stick with Aeropoxy.
>
>-Doug
>
>
Get the SPEC sheets on each of them and learn the differences. They are
available on the WEB if you care to take the time to try and find them. It
depends on many different variables including which of the many formulations
available. You just don't grab the first thing available and use it for
anything and everything. If you are going to work with the stuff, learn
something about it and use it right.
KernHend
>Why would Aircraft Spruce sell such a product and advertise it as good stuff
for room
>temperature cures?
>
>Furthermore, ACS says Rutan Aircraft Factory (RAF) recommends its
>use for all homebuilt aircraft applications.
>
>Furthermore, ACS sells West System epoxy and says it was developed
>specifically for boat construction. Also, RAF "now recommends
>West for certain homebuilt aircraft applications where moisture
>is an issue". Floats?
___________________________________
Several years ago I had a meeting with Jim Irwin of Aircraft Spruce and pointed
out that he was selling West System epoxy for home aircraft building despite
the fact that Gougeon Brothers, Inc. did not recommend its use for this
application. I pointed out that ProSet (a Gougeon product) would be a better
choice. His basic answer was that ACS is a distributor and sold what was in
demand without passing a whole lot of judgement on the buyer's choice. I'd
take this more or less as a marketing decision based upon politics rather than
good technology.
My answers to your two previous posts are based upon sound technology, not
politics. You, of course, can use whatever you want. It is your airplane.
All I said was that you can't get a high Tg on any resin with an RT cure and
that you can only get a high Tg with an elevated temperature cure IF the resin
formulation has the capacity to ultimately have a high Tg. Here is the reason:
Tg is closely tied to modulus. High Tg resins have high moduli. So high, in
fact, that they chemically "lock up" at some point when cured at room
temperature and no further crosslinking will take place. The molecules become
inflexible and can no longer get close enough to each other to react. We call
this "B" staged. The resin is quite hard and can even be sanded if a lot of
heat is not generated. "B" staged resins can test very high in mechanical
properties but are seldom tough. They are often brittle and easily shatter.
Initially, during a post cure B staged resins become soft. The molecules have
become more flexible and can bang into each other to chemically react
(crosslink). Hold the resin at an elevated temperature and over a few hours it
will become stiffer. Finally, it will "lock up" again if there are additional
unreacted molecules. Raise the temperature further and crosslinking will
proceed IF there are additional reaction sites. Finally, a temperature is
reached where it is fully reacted and further heating will accomplish nothing.
My advice to you is that you find out if the Aeropoxy indeed has a Tg of 200F.
If it does, come up with a way to post cure your parts (be sure they are well
supported and ramp the temperature up slowly so that the Tg keeps up with or
leads the temperature slightly) and do it. Then paint your airplane white or
in a light pastel.
Kern
Bruce A. Frank
I'd like to thank you for some of the most informative posts I have seen
here on RAH. Thank you for investing your time.
Bruce A. Frank
HLAviation
>pick
>any epoxy. I will also add that each of the epoxy makers offers multiple
>formulations with varying transition temperatures, working times, pot life,
>wetting capabilities, peel strength, compression strength, and so on. The
>important part is to learn a bit about them and make your choice according to
>need, especially if you are thinking of using anything besides the one
>specified by the plans or kit manufacturer.
>
>There are quite literally hundreds of different adheasive, epoxy, and glue
>formulations / products available today. They are absolutely remarkable in
>the
>various capabilities offered but can blow your mind in trying to determine
>which to use for a given application or process. I have spent many hours
>digging through the spec sheets and comparisons. The result is more
>confusion
>than anything but some knowledge is slowly sinking in.
>
>
>Bob Reed
One thing I like about System 3 is that there have been planes built with it,
and they have excellent technical support available.
Sean trost
Thanks !
got a Kayak crosslinking now....
all the best
Sean Trost