Fiberglassing question

[swatman260]

I'm trying to work on the interior of my body and have a question about the strength of fiberglass sheets. My plan is to finish my interior similar to that of Ex Junk's, in that I am laying fiberglass over foam throughout the interior, rather than using upholstery. I have wooded the sides with 1/2' ply, which has been glued to the sides with construction adhesive. In between the wooden slats will be shaped foam, giving my interior the shape that I want. My plan is to now lay fiberglass over the foam, sandwiching the foam and ply...My problem is that I don't really know how many layers of fiberglass cloth I need to use. Will one layer of heavy-duty cloth be sufficient for an interior, or do I need to do multiple layers? Obviously, the fiberglass will add a bit of structural rigidity to the body, but my main intent is to simply have a nice smooth interior. I do realize that the interior will take a bit of a beating though, from climbing in and out, to simply leaning against the body while driving. I have had very limited experience with fiberglassing, so I would appreciate some advise of how thick to make the glass.

 

[EX JUNK]

Since my son, Rob, is my glass guy and I gave him a call in order to answer your question. He said to not use cloth but to use mat as the cloth will tend to print through in the heat and since you live here in Florida you should be concerned about that. The mat that he uses is 1 1/2 oz. which is about 1/16". He suggested laying up a minimum of three layers but four would be better and to use a general purpose resin that is available everywhere. When the glass has cured you should rough is up with at least 80 or coarser grit paper. Then for a smooth finish completely coat it with Duroglass short hair filler and sand smooth and prep for paint as usual.

Jim

 

[swatman260]

Jim, you are the man. Not only did you answer my question, but you gave me complete directions. I love it. Now, I just need to find a reasonable source for the mat. Our local West Marine is pretty pricey.

 

[EX JUNK]

Jim, you are the man. Not only did you answer my question, but you gave me complete directions. I love it. Now, I just need to find a reasonable source for the mat. Our local West Marine is pretty pricey.

You're welcome, glad to have helped.

Jim

 

[choppinczech]

I have these for the different combos of glass I use. This one is for 1.5 oz. mat.





1 layer = .060
2 layers= .100
3 layers= .130
4 layers= .140
5 layers= .160
6 layers= .200
7 layers= .230
8 layers= .250

Keep in mind though, that these are made on a flat surface where excess resin can be easily rolled out. In real world layups, where excess resin is more likely, expect a bit thicker measurements.

 

[swatman260]

Awesome. That helps as well. After laying the wood slats and foam, I have about an 1/8" lip left for glass...so that should be 3-4 layers, just as Ex Junk recommended. Sounds like I'm on the right track with this.