Unfinished fiberglass and the sun...

[jbDC9]

This is probably a silly question, but I've been wondering about it, so here goes;

I've been flying my -8 for 7+ months and 150 hours, but still haven't filled and primed/painted the cowling or canopy skirt. Too much time at work, family issues, I'm lazy, etc. Really, I'm gonna get to it some day. In the meantime, does leaving the unfinished fiberglass parked in the sun to bake for a few days affect it in any way, like weaken it or perhaps cause any delamination?

I haven't thought much about it up until now since it lives in a hangar and hasn't really spent any time parked outside for extended periods, but now it looks like I might be heading to Oshkosh on somewhat short notice... and having it out in the sun for 4-5 days has me worried all of a sudden.

What'cha think, am I being paranoid?

[painless]

I don't think the amount of time you will leave it in the sun will be a factor.

The main thing I would be worried about is getting oil, dirt, grime etc worked into the fiberglass before you get it sealed with at least primer. Makes for some major headaches for your painter (you?) trying to avoid problems down the line with things like pinholes re-appearing for example.

Did you seal the interior of your cowl?

Regards,

[jbDC9]

Yep, interior is sealed with resin... the only thing collecting on the outside is bug guts, and I try to keep that stuff wiped down from time to time. No oil/grease on the outside.

[David-aviator]

Originally Posted by jbDC9

This is probably a silly question, but I've been wondering about it, so here goes;

I've been flying my -8 for 7+ months and 150 hours, but still haven't filled and primed/painted the cowling or canopy skirt. Too much time at work, family issues, I'm lazy, etc. Really, I'm gonna get to it some day. In the meantime, does leaving the unfinished fiberglass parked in the sun to bake for a few days affect it in any way, like weaken it or perhaps cause any delamination?

I haven't thought much about it up until now since it lives in a hangar and hasn't really spent any time parked outside for extended periods, but now it looks like I might be heading to Oshkosh on somewhat short notice... and having it out in the sun for 4-5 days has me worried all of a sudden.

What'cha think, am I being paranoid?

You are not being paranoid, but 4 or 5 days probably is not a big deal.

But Burt Rutan did make a big deal of not exposing fiber glass to direct sun light. Ultra violate light does cause plastic to break down and he proved it in the desert sun around Mojave when he was becoming the EZ guru. The sun completely destroyed plastic parts he used in the test but I think they were exposed for a year.

[DGlaeser]

UV does degrade the resin over time, so a coat of primer is in order at your earliest convenience.

[jbDC9]

Thanks for the responses guys; I've been meaning to order up some Smooth Prime from ACS and get going with it, but with my limited days off... and the choice is fly or work in the hangar, sanding and getting covered with dust, I usually end up going flying. Shame on me... but now I've got OSH week off and my wife said I'm free to go; decisions, decisions...

[cytoxin]

if you find fibers exposed you can put a coat of resin on it. but it will take more than a week or two for that to happen.