fiberglass tank

[JerseyRat]

Been wanting a tank for my daily rider and wanted to try fiberglass. I've never worked with fiberglass before so I did some research and this is how I'm doing it. First pics of my rider...
Found sheets of "hobby foam" at home depot and traced an outline of the tank shapes
Cut them out with my skilsaw

Then after some sanding/shaping...

the trick here is to remember you're not sanding metal, a little goes a long way. I was using some blocks I had left over for sanding sheetrock.
Next, I used painters tape to shield the foam from the resin...
Notice I masked off a small area with the painters tape to contain the mess.
Here I dry fitted the fiberglass cloth

Notice the homemade measuring cup in the background.
Time to lay down some glass..

I worked with 4 ounces at a time...plenty. First batch started gelling up, so you don't want to mix too much. I layed down a base coat of resin, then the cloth then some more resin and it started gelling. Have plenty of mixing cups ready. I put down three layers of cloth with a layer of resin after each, the last layer layed on pretty thick...

I'll let these dry overnight and hopefully have an update tomorrow.

 

[JerseyRat]

Forgot to mention I used bondo brand resin/cloth and followed the directions for the hardener/resin mix. Working time was about ten minutes just like the instructions say. I used a small paintbrush to lay the resin on and work the cloth into the corners. Have a few of those handy 'cause if its starts gelling you're not gonna want to keep using that brush. I wore a mask and had the garage door half open as well as the normal sized door open and I didn't think it was bad but my wife who was in the house which is about twenty feet away said she could smell the fumes.

 

[LukeTheJoker]

Great work and a good write up! Cant wait to see the results!

Luke.

 

[bebopblu]

Thanks for the detailed photos. I am going to try this with one of my straight bars. Cant wait to see more

 

[g-ratter]

Some hints for doing this:
If you can get the blue foam it will hold up to the resin.
You do not need a "layer" of resin. All you need to do is get the resin to soak into the cloth.
You do use a layer of resin as a final coat to help seal up the weave in the cloth but it helps if you have the additive (called wax) to help in the sanding process.

 

[axsepul]

very nice, working on something similar

 

[JerseyRat]

@ g-ratter, do you mean resin, followed by three layers of cloth then resin over?
more updates...so I got impatient, or maybe it was the fumes, and while they were drying I hit them (a little)with the heat gun. This is after cutting off the excess with a dremel...looks like the foam started melting.

No worries that's on the inside. On the outside its gonna need a lot of sanding/filler to look decent.

 

[American Vintage Bicycle Supply]

8)

 

[g-ratter]

No need for resin first.
You have made your foam blanks and mounted them on something stiff to keep them flat.
Cut and lay a piece of your cloth on the blank then pure/brush your activated polyester resin onto the cloth. You want it to soak into the cloth but not puddle on it. If you can see the weave still with no "white spot" (these indicate dry areas) then you have enough resin on it.
Then you can other layers as needed. If the cloth is thin enough and you get some practice in it is possible do multiple layers at once.
To get a smooth surface you then brush a layer of resin on that is activated and has what is called a wax in it. The wax allows you to sand it without gumming up the sandpaper.