Fiberglass bodies and wood...?

[T2T]

What kind of wood should I use to reinforce the body on my RPU.........? I need to know from someone that has actually done this or someone that knows. 5/8" plywood seems pretty good to me , but what do I know?

[cycledog]

I have never done this but I have to ask. Why would you choose wood over metal tubing?

[WIZEGUY]

The 'dog beat me to the punch.......are you not wanting to use the steel?

[donsrods]

You can't use steel. It has a different expansion/contraction rate than fiberglass. Wood is the preferred material to use. I bought select pine at the local Home Depot, and cut it to fit. Give me a little while (I just got in and haven't eaten yet) and I'll post some pictures showing how I did mine.

Don

[donsrods]

Ok Tom, my dinner is cooking, so I'll get started. This is going to be a long thread, because I have to break it up into lots of posts. My computer is screwing up, and if my post is too long, it freezes up, and I have to shut it off and start over. Plus, it is impossible to explan fiberglassing in a short post. So here goes:

First of all, your choice of 5/8 plywood is good. I use exterior grade sheating plywood. Marine grade is not needed and is hard to find and expensive. You will be coating it with fiberglass and resin, so it will never rot, plus it already has waterproof glue bonding it. You will want to cut the plywood slightly smaller than the area it needs to cover, so the plywood is not touching the body. Leave a gap all the way around of about 1/4 -3/8 inch. Otherwise you will get shadowing through the glass. (don't ask, too long to explain)

The floor is the first thing to install. Set the body on the frame as you want it to end up, and place your cut out floor inside. Shim it up to allow room for body mounting rubber.

Here is mine after that process.

Don

[donsrods]

Next thing you will want to cut out is the piece of plywood that will be the inside of your firewall. Here is mine.

Notice the gap I left around the wood in the last picture, for the same shadowing reasons.

[donsrods]

Good time to talk about materials you will use. There are two kinds of resin, polyester and epoxy. Epoxy is better, holds better, and is much more expensive. You do not need to use epoxy, even most boats are made from polyester. It is what I always use. Buy your resin and cloth from a marine discount store. Not one of the ones like West Marine or Boaters World, but a real hole in the wall marine supply house, or a fiberglass house. Otherwise you will pay way too much.Buy your resin in gallons, as shown below.

I used three gallons to do my '23 T bucket.

[donsrods]

There are two kinds of fiberglass material (actually lots more than two, but two MAIN types) One is called mat, and is the stuff that has random strands running in all directions, and the other is cloth, and is the woven one that has a crisscross pattern to it.

I use mat only because it conforms better, and bites into whatever you are bonding it to better. Here is mat. I bought 10 yards and will need more to finish. It cuts with scissors.

[donsrods]

Some tools you will need are:

Scissors you don't care about (they will become coated with resin after a while.

Throwaway paint brushes

Rollers as shown below to push the glass into corners and roll out bubbles

Mixing buckets.

[donsrods]

Buy yourself a gallon of acetone and at least a gallon of wash thinner (cheap laquer thinner) If you buy one gallon at Home Depot it's $ 14, if you buy 5 gallons at the automotive paint store, you get 5 gallons for $ 32. Much better deal.

I also buy my plastic buckets at the auto paint store, much cheaper. Buy lots of them, you will be using them a lot. Get stir sticks too. I also buy latex gloves by the box of 100, you will use these constantly during the fiberglassing process.

Now that you have your floor and firewall cut out, you have to wipe down the entire interior of the body with acetone to remove any mold release wax. Fiberglass does not cure unless wax is in it, and this wax rises to the surface when it cures. You need to remove it with rags and acetone. Then grind every inch of the interior with something like 60 grit to give tooth to the surface, and then wipe it again with acetone.

Here is mine after all that.