Cutting Down a Tonneau to Fit

[Dan in Pasadena]

Has anyone here done this?

I have a chance to pick up a FREE long bed fiberglas tonneau and I'm wondering if modifying to fit our short bed trucks is doable or just too much hassle?

I know Gaylords makes one to fit our trucks but its over $1000. I wouldn't mind saving most of that after all I've spent on my truck so far.

[dsraven]

fiberglass isn't that tough to do. look into woven roving combi mat, it is like heavy duty woven mat with the crosshatched shorter hair stuff on top (google). one piece and you instantly get a nice thick build up. use a fiberglass roller to get the bubbles out. spray or roll on some gelcoat coats when done. non waxed resin isn't sticky when dry but then you have to scuff it to lay up again so good for the final coat. waxed is gooey when dry and takes a bit to get the goo off for the final finish. check with your local boat repair or plastics supply place, not that tough though if you have an outdoor place to work. stinky.

[dsraven]

or add onto your box so the tonneau fits, lol.
it's free, nothin to lose but time. you might even learn something while you're at it.

[mr48chev]

I'd agree you have nothing to loose except some time and the cost of the material you need.

I've referred to this book by Don Casey a lot of times and he is pretty good at explaining the process of repairing fiberglass.

One thing you have to do is grind it down on both sides of the repair to V it in so you can build it back with successive lager layers. I took all the through hulls out of the bottom of my sailboat as none of them were used anymore because what they went to had been eliminated long before I bought the boat and the fitttings had been plugged on the inside. Not good if one of the plugs leaks. I ground out an area that was a whole lot larger than the hole but tapered to the outside and started building it up with layers of cloth or mat each one cut just that much larger than the one before until I had built it back up level and had a repair that isn't noticeable and won't fail. Lots of itching on that one though.

That is the other thing with fiberglass, it doesn't bother some guys much and other guys can't get close to it without itching to no end. I sold a really cool Devin sports car body (pre kit car) shell years ago because every time I moved it I itched for hours. I still kick my but for selling it as it was in the raw never touched glass when I traded for it. I've got a 1600 CC 16 valve engine out here that would make it scream now.

I'd cut and fit it and maybe hold the pieces together with some 1/4 plywood and machine screws until I got it fitted to my truck and then start working on the seams where I cut it to make it one piece again.

[Dan in Pasadena]

Thanks for the encouragement, guys.

I think it would have to be shortened AND narrowed. So essentially four pieces. Not sure I’m up for THAT much work on my first Fiberglas work. I’m pretty anal and I’d be annoyed if it didn’t come out factory-smooth.

[pvienneau]

Looks like you are spending the G.

[b-mac]

I used to do tons of fiberglass work before I discovered welding.

It's amazing to be able to make whatever shape you need. But the sanding and finishing sucks.

I also think it would be easier to manufacture your own cover from scratch than it would be to modify one that was cut 4 ways.

[mr48chev]

Good point There are three old fiberglass conversion van tops sitting about a mile and a half from me where they have been for years. I've been wondering if I could cut out a piece that would work for my truck for a long time. I'd cover it with convertible top material so it wouldn't have to be ready for black paint slick. I was actually wanting to see if Gayords had a blem that they would sell for that purpose.