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canopy fiberglass epoxy question

dwranda

Well Known Member
I was at a forum at Oshkosh and these guys didn't recommend using West systems epoxy for the canopy fairing. Something about West only being good up to about 130 or 140 degrees. They said if you paint the canopy area a dark color the heat retention could damage the epoxy/fiberglass layers and cause issues down the road. They recommended a couple other epoxies with higher temp ranges. I was under the impression most guys used West for this. Any opinions? Thanks!!
 
I was at a forum at Oshkosh and these guys didn't recommend using West systems epoxy for the canopy fairing. Something about West only being good up to about 130 or 140 degrees. They said if you paint the canopy area a dark color the heat retention could damage the epoxy/fiberglass layers and cause issues down the road. They recommended a couple other epoxies with higher temp ranges. I was under the impression most guys used West for this. Any opinions? Thanks!!

West does have a relatively low glass transition temperature (Tg). Google the term; you'll find plenty of material.

I'm not aware of low Tg being a problem for a canopy fairing. My all composite tip-over Showplanes canopy is assembled, filled and skimmed with West 105.
 
You'd think that if it were a real issue, rather than theoretical, it would be pretty well known by now. It's not like there is a huge shortage of RVs that have West Systems epoxy, painted every conceivable color, parked under the hot Oshkosh sun for a week every year.
 
Yeah this was the first I had heard of West not being recommended. I just got a batch in to do the fairing and was afraid I made a mistake buying it for that purpose. If it's good enough for Dan H. it's good enough for me!
 
Exotherm

The reason West 105 is often recommended against is that it will exotherm quickly. After mixing the eopxy with the hardener, you must pour it out of the mixing cup within a few minutes or else it will heat up and become unusable.

West 105 is excellent for micro filling (mix it up and spread it out quickly) and its fine for small and thin fiberglass layups like fairings.
 
RV-7/12 Epoxy-Glass Canopy Install forum Airventure 2019

I was at this forum also.

The presentation files are at https://www.customtechllc.com/copy-of-past-projects

=======================

RV-7/12 Epoxy-Glass Canopy Install
Airventure 2019
Presenters: Richard Kaczmarek, D. Michael Bergen

The all composite windshield-canopy method eliminates the aluminum skirt on the canopy. This process is not hard but takes time and includes lessons learned. The end result is a better fitting and quieter canopy.

=======================
 
I was at this forum also.

The presentation files are at https://www.customtechllc.com/copy-of-past-projects

=======================

RV-7/12 Epoxy-Glass Canopy Install
Airventure 2019
Presenters: Richard Kaczmarek, D. Michael Bergen

The all composite windshield-canopy method eliminates the aluminum skirt on the canopy. This process is not hard but takes time and includes lessons learned. The end result is a better fitting and quieter canopy.

=======================

Yep that's the one!
 
To get the higher Tg with MGS requires elevated temperatures for extended times, for example from the data sheet available at Aircraft Spruce:

10 hours at 176F: Tg=194F
20 hours at 140F: Tg=176F
15 hours at 122F: Tg=158F

The advantage of West Systems epoxy is the room temperature cure gives
Fast 205 hardener: Tg=142F
Slow 206 hardener: Tg=139F
 
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