Fiberglass repair

[vfrazier]

Gents,

I've got a fiberglass cowl in my shop the has tornado damage. The cowl does not have the honeycomb layer that newer cowls have, just layers of glass.

It was impacted by something that left a small hole and tear. Those will get sanded and repaired with new glass.

Here's my question, I'm more worried about the cracks that popped back into shape after the load was removed and how to keep them from reappearing later. In other words, the glass was damaged but retained its original shape and I don't want a bunch of spiderwebs showing back up in the paint later after it's back in service.

Aside from replacing the entire top half, is there a fix?

Thanks in advance.

[RV6AussieNick]

Sand back all the paint to expose any hidden damage, inspect the glass inside and out in a bright light, if you find or suspect any damage to the glass matrix sand the aria along the crack/damage, depending on how thick the panel is try to maintain a 1-20 taper, don't sand all the way threw, clean the area well with acetone, cut up some S Glass to replace removed material, increasing each piece with a 1/4 over lap all the way around the previous layer until you have replace the thickness to the original contour. Very important to use a good quality epoxy laminating resin to achieve a good bond between the old glass and the new repair.

You might be able to find some hints on the web, do a google search for Fibre glass repair.

Cheers,

[DanH]

Search the word "scarf"

The serious discussion was here:
http://www.vansairforce.com/communit...ighlight=scarf

[az_gila]

Since I presume it is an early cowl with the white gelcoat...

Check that the cracks are actually in the glass layers and are not just gel coat cracks. The gel coat is usually more brittle.

You might be able to get away with just sanding the cracked gel coat off...

[vfrazier]

Scarfing leaves me barfing. Sanding isn't outstanding. Stuff that's sticky, I find to be icky. I can't imagine why anyone would make an entire airplane out of this stuff.

I haven't sanded the paint off yet. I was hoping for a magic fix, like on those late night car polish infomercials.

I do know that there is no gel coat on this cowl.

I guess I'll get started on stripping it to see what's actually under the paint.

Where can you get honeycomb material, without any covering, just bare honeycomb? Just curious.


Sigh......

[David Paule]

Once you get down to the bare fiberglass, damage will probably look like a white opaque line.

Dave

[Joerpilot]

Aircraft spruce carries some. Here's a link

http://www.aircraftspruce.com/catalo...s/01-00488.php

[vfrazier]

Thanks to all for all the advice and assistance.

[F1Boss]

Originally Posted by vfrazier

Thanks to all for all the advice and assistance.

Ask the manufacturer....

Carry on!
Mark