Reinforcing fiberglas with steel?

this appears the kind of poorly thought out details on many light aircraft I have seen before. I am an engineer that worked many years in aircraft industry. It can be fixed by doing the redesign you suggest.

It is not clear to me why you can not make the pants thicker around the AR bolts. It seems to me you need more strength there, and you can add thickness to the outside, as well as the reinforcement you suggest on the inside. It means you would have to repaint it, but it would be a more permanent repair. Be it fiberglass or heat formed thermoplastic you can reinforce it by getting a good bond to add thickness to the outside, which would also serve to strengthen the broken out area of the original AR bolt hole. once done you feather the edges, sand it smooth and prime and paint it.

Good luck

 

I'm looking at repainting all three of the wheel pants anyway.

Harvey

 

I haven't read much of the thread, but a little bit about the expansion rates of steel vs fiberglass. A long time ago on another forum the same question was asked and I ventured that there would be big problems, but it turned out there are sailboats framed in metal tubing, covered in fiberglass, that pointed out that I maybe I didn't know what I was talking about.
A lot of molds are reinforced with metal, if there is a problem with the different expansion rates, it would seem a mold would be the last place you would want it, but in reality, there it is.

 

Harvey,
this idea is a bit left field but if indeed they are made of pvc then you could make some cheek and sleeve reinforcements from pvc pipe and glue it all in with high pressure plumbers glue.

 

I would use SS plate sheet. Make a pattern using cardboard. Trace the pattern onto SS, cut it out and bend to fit around and over the FG.
I would wrap-form the plate entirely around in a 'C" shape the FG connection points.
the SS would need to be thick enough to be useful, I think maybe 60 to 80 thousands would be good.
Then I would rough coarse grit sand the SS
Then I would epoxy glue repair this to the FG with an overlayment of FG.
Maybe that would hold up. It might also help to have some small holes perforation drilled in the plate for the glue to help hold it, and I would use some filler in the epoxy to give it more strength, such as milled fibers..

 

I think simply bulking up the existing laminate (or plastic) with additional material around the AR pin is the easy and logical way to go. The mounting fasteners seem to have enough meat around them, it's just the AR pin that don't have enough material to prevent vibration and torsional loads from cracking out the hole. I'd just "fatten" up the laminate around that collar, so the AR pin has more meat to bear against. Fair in the new stuff and repaint. It would be nice to know what material it is, but I've had good results epoxy bonding to most rigid plastics.

 

+1 for PAR.
This is an airplane, least weight is better.
The thing lasted a long time with the original plastic, just a little help is best.