Need help reinforcing fiberglas (with Carbon Fiber?)

It may look simple and easy but a small repair like this can be tricky. You're reconstructing a part that has two sides, not just a simple fill.
You're duplicating an existing or pre existing part, from what I can see. And in order for the new repair to stay fixed, part of the broken piece may have to
be ground back and some type of form needed for the back of the repair piece.

Simple but you need a pro with a some finesse. Sloppy work and you'll be sanding for days. I would consult a few places in your area
first. Woodchuck: I never suggested a dry lay up. Only a proper resin to cloth ratio, which is fundamental to any glass work. Strength comes from the cloth and not the resin. Check out the West Systems website, they have a support line and a blog. Good luck.
 
EmilioG said:
first. Woodchuck: I never suggested a dry lay up. Only a proper resin to cloth ratio, which is fundamental to any glass work. Strength comes from the cloth and not the resin. Check out the West Systems website, they have a support line and a blog. Good luck.
Click to expand...

I know you didn't suggest a dry layup, you suggested not over saturating. There's a bigger danger to that. So over-saturating and removing is a better way, than less and risking a dry layup. Carbon absorbs way more than glass. Also this is not a hard repair at all.
 
Harvey said:
Good Mornin' Guys, thanks for your inputs. Unfortunately, while it probably wasn't your intent, the process sounds very complicated; especially since my fiberglas/epoxy/polyester/carbon fiber experience is practically nil. Therefore, instead of trying to do it myself, I'm wondering where I can HAVE it done.

Here on the Gulf Coast, we have boat repair shops everywhere, ranging from award-winning to fly-by-night. What do I need to look for or ask in order to find a shop that can do what I need?


Hi Bob, thanks for the warning but I'm an A&P-IA.


All three wheel pants came from another C150 that was a different color (they were an eBay purchase) and will need repainting anyway to match my 150.
Click to expand...
Ah, the rest of the story! Use your A&P/IA good judgement... ;) This is not really a safety of flight issue, just needs a repair that will last...
 
Harvey, I did fiberglass and epoxy repair on boats for decades in the marine and commercial fishing industry. this looks like a really simple and easy repair. I great project for you to learn FG work, if you choose to do so!

I think the only two things I would ask a shop are: how much and when can I get it back. :) The job is going to be dead simple for any FG shop to accomplish.

If you choose to do the work yourself, here's a method you could use. The damage looks minor along the top of the fairing and around the broken area where a bolt and washer were used to secure the top of cowing to the wheel strut. I would to grind off and fair back the gel coat using a 4" angle grinder and fine wire wheel, then build up 1/4" or 5/16" of matt and resin to reconstruct the countour of the part. Use a backing block made out of plywood taped to the fairing and a small separator sheet of plastic garbage bag if you want to form the inside edge. Make the bolt area at the top it a bit thicker, say 1/8" oversize, for extra strength around where the bolt and washer impart crushing stress to the fairing. Also add an inch or two excess lapped up over the top. This to ensure equal thickness around the edge when you trim it off. Then when dry, cut off the excess with a jig saw or grind down with a belt sander, and sand to shape. All done. You can always add one or two finish coats of resin to achieve a nice smooth and blended top surface.

I like to paint raw fiberglass with one part marine primer, usually Interlux Pre-kote. then finish with a couple of coats of any good grade polyurethane.

My .02 worth is that epoxy and carbon is way overkill for the repair. FG resin and cloth will give you more than enough strength and last litterly for ever in an operable condition, and be very cost effective. If you do elect to do the job yourself I would think you could do this in an afternoon for $50 worth of materials, and have a repair that would last for decades. Carbon fiber and epoxy would work but will cost you 3x or 4x as much and take three or four times as long to apply -with no added benefit in part serviceability when your done.

The main thing I like about fiberglass, versus epoxy is that you can control pot life with FG resin by altering the amount of catalyst you mix in - anywhere from 10 minutes to upwards of an hour before it sets off. This means you can add layers of cloth at a very rapid rate , and finish off with a few nice skim coats of resin in no time. Most epoxy takes a looong time to set up, sometimes overnight - turning a simple job into an endless train of "watching paint dry" before you can apply another layer.

Cheers! I would urge you to try it! Let us know how it comes out.

Glenn
 
Last edited:
I recently used a mix of Bondo paste and Bondo fiberglass resin, mixed together to form a strong lasting patch material. Lay up regular cloth and resin, then. Add hardener to each material first, then mix together. 1 2 3 easy. Sand, paint, done. You can use a piece of waxed PVC to form the ID if it's the same ID as available PVC tube, or something else suitable. Home Depot has all this stuff.

West Systems has a fast setting epoxy >> http://www.westsystem.com/fiberglass-boat-repair-kit/

There are UV cured resins. Many modern materials are not like your Grandfathers stuff. Detailed info on the website. Great epoxy. Used it many times. Sets in 15-20 minutes. Test it out on a piece of lumber or scrap FG part. Very easy once you do it a few times.
 
Last edited:
Thanks for your inputs guys. I'll keep you posted on how it turns out.

Harvey
 
I learned that a new neighbor has composite construction experience and I met with him yesterday morning. He identified my nosewheel pant as not being fiberglas at all but a form of plastic. (The hint of layed-up fibers under the paint had me thinking it was a form of 'glas.) Anyway, we found a trial-sized PolyFix kit in the latest Aircraft Spruce and Specialty catalog and it should be here before next weekend. Supposedly, PolyFix is effective on PVC and all kinds of "plastics" common in the aircraft industry. At $22 for the kit (+another $16 for friggin' hazmat mailing fees), I figured it'll be worth a try. I'll let you know how it turns out.

Harvey
 
Well, my neighbor and I repaired my wheelpant with the PolyFix yesterday evening and I'm happy to report that it worked out very well. I've got a bit of sanding to do before I get the pant's paint touched back up but I'm pleased with the repair so far!

Harvey
 
You must log in or register to reply here.
Back
Top