information pulled from a epoxy site.
Different amounts of resin are required to wet out different forms of fiberglass. For example, one gallon of resin will wet out approximately the following amounts of fiberglass:
40 square foot of 8 to 10 oz. cloth
50 square foot of ¾ oz. mat
30 square foot of 1½ oz. mat
35 square foot of 24 oz roving
In the event successive layers of glass are laid up before previous layers gelled, coverage will be greater.
The percentage of glass to resin in various laminates is:
Type of Fiberglass %Glass %Resin
Chopped Glass Lay-Up 25 75
Mat Lay-Up 30 70
Woven Roving Lay-Up 40 60
Cloth Laminate 45 55
The weight of a finished fiberglass and resin laminate is approximately:
Thickness Weight
1/4" 2 lb.
1/8" 1 lb.
1/16" 1/2 lb.
The above figures will vary depending upon the worker, thickness of laminate, and method used. In general, the higher the percentage of glass, the stronger the laminate.
Fiberglass Quantity question for you glassers?
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• Page 2 of 2 • 1, 2
by Esteban » Sat Feb 21, 2009 4:45 pm
I used more epoxy than other people may need to because I've used epoxy in more areas than just the sides, roof and galley lid. I epoxied both the bottom and top of the floor to seal and water proof them. That was not a boo boo. The epoxy set up well. Thought I was off to a good start as an epoxying newbie.
I boo booed the driver's side wall twice.
The first time, about May or June 2008, I rolled on epoxy without any fiberglass cloth to wet out the plywood and begin filling in staple divots with an epoxy and micro balloon mixture. Within a few hours it seemed to begin hardening OK to the green stage. After 3 or so days it was still a little green when i pressed my finger nail into it. It gummed up sandpaper when I tried sanding it. So one miserable day later I sanded and scraped all the epoxy off.
I tried to measure the epoxy and hardener carefully but did notice I seemed to be using up the hardener supply a little faster than the epoxy. At the time I didn't think it mattered too much. (Wrong.)
About June or July 2008 I fiberglassed the side (the first time with cloth). I again wet out the fiberglass cloth on that side with a half roller and a squeegee. Let it set up to green and then rolled on 2 or 3 more coats. The top coats set up nice and hard. Did preliminary sanding to smooth the side. Yippee, it seemed to be OK this time. Life intruded so work on the TD slowed.
Recently I sanded the side again in preparation to begin fairing it with mixture of micro balloons and epoxy. I accidentally sanded through some of the fiberglass and encountered gummyness in the lowest layer of epoxy. Was very, very bummed out that after 8 or so months again some epoxy had not set up. So I took off all the fiberglass down to solid wood.
I didn't have enough epoxy to complete all the fiberglassing ahead so I ordered another 3 gallon kit. This time with half fast hardener and half slow hardener. My first kit had all slow hardener.
I've now fiberglassed the driver's side wall a second time. Squeegeed and rolled on the epoxy and fiberglass. Used only fast hardener. It's all set up OK. It came out a little bumpy. Sanded the whole side to smooth it some and to key it for more epoxy and micro balloons. I've filled in most low spots with the mixture of epoxy and micro balloons. OK again. More sanding. I've begun applying an overall smooth coat of epoxy and micro balloons so I can sand the whole side flat and smooth enough to be ready to paint later. So far so good.
With an extra large supply of epoxy I'll use some of it to seal the plywood inside the sandwich walls. May use epoxy instead of glue to attach the 1/8" birch plywood inside the cabin.
If I have some epoxy left over after the TD is done I have some wood rot I need to repair around the windows and eaves of a rental house. So any "extra" will not go to waste. Except for my boo boos.
Added information. My walls are 54" tall and about 11' long. After the 4 oz. cloth was wet out it took about 15 oz. of epoxy for each additional coat. I didn't keep track how much epoxy it took to wet out the fiberglass cloth. It probably was at least twice as much. Before the cloth was wet out I first applied a sealing coat and let it dry to a green stage. This also took more than 15 oz.
I boo booed the driver's side wall twice.
The first time, about May or June 2008, I rolled on epoxy without any fiberglass cloth to wet out the plywood and begin filling in staple divots with an epoxy and micro balloon mixture. Within a few hours it seemed to begin hardening OK to the green stage. After 3 or so days it was still a little green when i pressed my finger nail into it. It gummed up sandpaper when I tried sanding it. So one miserable day later I sanded and scraped all the epoxy off.
I tried to measure the epoxy and hardener carefully but did notice I seemed to be using up the hardener supply a little faster than the epoxy. At the time I didn't think it mattered too much. (Wrong.)
About June or July 2008 I fiberglassed the side (the first time with cloth). I again wet out the fiberglass cloth on that side with a half roller and a squeegee. Let it set up to green and then rolled on 2 or 3 more coats. The top coats set up nice and hard. Did preliminary sanding to smooth the side. Yippee, it seemed to be OK this time. Life intruded so work on the TD slowed.
Recently I sanded the side again in preparation to begin fairing it with mixture of micro balloons and epoxy. I accidentally sanded through some of the fiberglass and encountered gummyness in the lowest layer of epoxy. Was very, very bummed out that after 8 or so months again some epoxy had not set up. So I took off all the fiberglass down to solid wood.
I didn't have enough epoxy to complete all the fiberglassing ahead so I ordered another 3 gallon kit. This time with half fast hardener and half slow hardener. My first kit had all slow hardener.
I've now fiberglassed the driver's side wall a second time. Squeegeed and rolled on the epoxy and fiberglass. Used only fast hardener. It's all set up OK. It came out a little bumpy. Sanded the whole side to smooth it some and to key it for more epoxy and micro balloons. I've filled in most low spots with the mixture of epoxy and micro balloons. OK again. More sanding. I've begun applying an overall smooth coat of epoxy and micro balloons so I can sand the whole side flat and smooth enough to be ready to paint later. So far so good.
With an extra large supply of epoxy I'll use some of it to seal the plywood inside the sandwich walls. May use epoxy instead of glue to attach the 1/8" birch plywood inside the cabin.
If I have some epoxy left over after the TD is done I have some wood rot I need to repair around the windows and eaves of a rental house. So any "extra" will not go to waste. Except for my boo boos.
Added information. My walls are 54" tall and about 11' long. After the 4 oz. cloth was wet out it took about 15 oz. of epoxy for each additional coat. I didn't keep track how much epoxy it took to wet out the fiberglass cloth. It probably was at least twice as much. Before the cloth was wet out I first applied a sealing coat and let it dry to a green stage. This also took more than 15 oz.
Steve - SLO, CA
- Esteban
- Donating Member
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- Joined: Fri Jul 28, 2006 4:39 pm
- Location: California, San Luis Obispo
I use the yellow foam rollers too, usually cut the 7" roller in half and put it on a 3" roller frame, I mix small batches, pour them on flat work and spread with the roller. I usually mix batches fast enough to use the same container and stir stick. If you mix a big batch it will heat up pretty fast in the mix container, that's why I usually stick to a max of 3 or 4 pump batches of resin and hardener. Just the way I do it.
