Custom Fender – Part II.c (Fiberglass Reinforcement!)

So the shell was made. It was not very strong, and far from road worthy. First, we had to reinforce it. Since we made the fiberglass fender on the outside of the current fender, it’s safe to presume that the fiberglass copy is just a hair larger than what it should be. For that reason, we decided to reinforce on the inside.

We skipped a few steps without photographing, but basically we trimmed all the excess fiberglass strands to clean it up and then cut all the edges, and sanded them to make it crisper, otherwise it would be more like a case for the current fender. This still isn’t the final shape, but it’s getting closer.

The entire inside was sanded to remove bubbles, soft spots, unevenness etc. and then we cut fiberglass matting exact to fit. On top of the fiberglass you can kind of see it in the image, we used an aluminum screen door sheet to create a mesh support matrix, and when it dried it really, REALLY strengthened the fender.

Now, to apply even pressure to the entire inside of the fender while it was curing (because it kept peeling off) we use a trash bag filled with water, like a gigantic water balloon. If I were to do it again, I’d find a different way to do it, this was NOT desirable. If you decide to pursue this method, know that we use THREE contractor grade bags to make absolutely certain it didn’t break and ruin the entire thing.

You’ll note in the picture below that there are lots of clamps around the fender. They served two purposes, one was to line the edge and make sure the edges adhered perfectly, and the longer ones going across the width of the fender…well, this is why I’d try to find a different way to do this next time. When we put the super-water-balloon inside the fender, it bowed out the shape quite a bit. We used the long pipe clamps to compress the sides and return it back to it’s normal size while curing. It worked out okay for us, but I don’t think I’d risk it, because there’s a LOT of places to screw up, and frankly we did mess up a large portion of it. Luckily, the portion we messed up was being cut off anyway.

Rise and shine! After siphoning out the water VERY carefully (there were several GALLONS of water inside, and lifting was too risky) we used a blow drier to get out the last little bits of moisture and then let it cure for a bit longer.

Bondo time!