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Permalink Reply by P. Richards on June 19, 2024 at 6:25pm

If you have a local flying club within a reasonable distance, I would see if any of the members / Homebuilders can help you out as most of them have someone with fiberglass or composite experience.

Another option is a collision shop. Often there is a guy that specializes in fiberglass repairs.

Any boat repair, marina will do fiberglass work, but I can't vouch for how reasonable they will be.

Who knows,they might even do it on the side for you for cash or trade?

Sorry I'm not closer, I'd do it for you.

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Permalink Reply by Shaun D on June 20, 2024 at 9:43am

As a new builder I found fiberglass super easy to work with.

Buy the West Systems resin from Amazon or Spruce including the pumps which meter the amount

Spruce sells the cloth, it's very cheap 

Clean/rough up the surface you want to fix

Cut the cloth to the size of patch you want

Paint it with some resin to make it sticky

Slap it on the area

Keep adding more to get the strength/thickness you want

In between layers you can add those washers, can cut the hole out when its done obviously

After its dry you can sand it smooth

It's very strong, I've made all sorts of unusual shapes 

EAA and kitplane enthusiast have videos about this too

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Permalink Reply by John Austin on June 21, 2024 at 12:04pm

Ditto Shaun's advice!  Years ago, I was a novice to fiberglass, but there were so many DIY videos on YouTube that it was easy to learn.  The EAA also has several videos that deal with fiberglass. I used the West System with the pumps that pre-measure the ratio of hardener to resin and it always works great.

I would add to Shaun's instructions to taper-out the repair area and make the layers of patch successively larger so as to spread out the bond over more area.  Mix some micro-balloons into the resin to make a filler for sanding the patch smooth. 

My lower cowl is also held by #8 screws.  As an alternative to embedding washers, I simply backed the inside of the fiberglass with a strip of .025 aluminum and drilled the screw holes through that.  I bonded the .025 to the fiberglass with the West G-Flex epoxy using their recommendation to apply the epoxy to the aluminum and then scratch the aluminum with coarse aluminum oxide, scratching through the wet epoxy before clamping it in place.  This forces the epoxy into the scratched aluminum.  Then generously clamp the aluminum - there should be enough epoxy to get a slight squeeze-out of epoxy around the edges.  Still holding great 12 years later and not a single crack around a screw hole!  The screw holes were slightly countersunk in the fiberglass and I use Tinnerman washers under the screw heads.

Here's a pic of the inside rear edge of my lower cowl::

John

N750A

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Permalink Reply by Gary Welch on June 22, 2024 at 9:15am

I was wondering about doing something like this. Sems to make a lot of sense. Thx for the info!

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