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  1. #1
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    Default epoxy and foam compatibility

    I read a post about someone making a removable hard top and it got my mind thinking, now I got some questions. I plan on making a hard top for my aquasport this off season. I want to make it like the hard tops many manufacturers are putting on their ~23 fishing boats. Aluminum tube frame with a rigid hard top w/ rod storage and attenae mounts. Anyway I was planning on using ply and glassing it over, but weight is definetly an issue. So I am thikning glassing over foam would be not to difficult and weight a bunch less. So I want to lay fiberglass mat down with epoxy resin over the foam top. I was thinking of just using the ridgid insulation the lumber yards sell.What foam will epoxy resin not kill? I have teh traditional ridgid foam foil faced RMAX type insulation readily accesible, and can get my hands on a similar product called foamular with is similar but blue or pink in color and seems more elastic and "plastic-y".Which will work? I would rather use epoxy based resin but if nessecary I could use polyester resin?Give me your input,Thanks very muchTOny

  2. #2
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    Default Re: epoxy and foam compatibility

    Epoxy is pretty neutral, I dont think you'll have any problems with either sort of foam, athough I'm not sure about adhesion to foil, so the other one might be better. To be sure, you could get a small piece and do a test. Be sure to reinforce your attachment points. If you make a sandwich with glass cloth on each side instead of mat you will use less epoxy for similar or more strength and less weight.Some makers of sandwich hulls make the sandwich first and then drill and rout out an area with an L shaped bit through the hole which is then filled with resin for reinforcement and bolted right through.

  3. #3
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    Default Re: epoxy and foam compatibility

    Foam normally doesn’t have a problem with epoxy. Polyester resin will eat it up. I would start with Grant’s suggestion and try a little piece of foam with the resin of your choice. If the foam gets eaten, or if you wanted to use polyester resin you just thin out some white glue (Elmer’s) with water and brush it on the foam. If you get it too thin, apply a second coat. After it is dry you can apply whatever resin you want. The dried glue acts as a barrier to keep the foam and resin separated.Your idea of using foam is a good one. You can also use white Styrofoam sheet that can be purchased in a lot of places, including craft stores. It is kind of flexible so if you want a slightly curved top you can nail a couple boards, in parallel, to the kitchen floor (don’t get caught doing this) and bow the Styrofoam between them. Apply the fiberglass mat and resin to the top, and maybe curve it around the sides. After it’s dry it should hold it’s shape and you can take the nails out of the kitchen floor, roll it over and do the underside. You get the idea…The angled bit Grant mentions can be made by bending the tip of a common nail to form an “L”, with the foot sticking out about 1/4 inch. Snip off the nail head, stick it in your drill chuck, and let ‘er rip. Fill the void with epoxy. I do this wherever I put hardware either into or thru cored fiberglass. It makes a solid area for the hardware and prevents water from ever getting into the core foam.

  4. #4
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    Default Re: epoxy and foam compatibility

    There is some stuff called Plascore, and some other stuff called Auromat. Plascore is stiff like wood but about 1/10 the weight. It comes in thicknesses from 1/4" to 2" to be used with fiber mat. Very light and strong, you would be able to walk on it after glassing it. Auromat is used as a core between fiberglass laminates. I saw them @ the place I bought my supplies from.www.fiberglassservices.com(800)226-8112 ask for Ryan they are local to me, but will ship anywhere in the US

  5. #5
    Commander Realgun's Avatar
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    Default Re: epoxy and foam compatibility

    I would think you would want to vacuum the epoxy and glass to the foam core. Basically your making a surfboard. I have heard of this method but do not know how hard that would be to do. Sounds interesting though.

  6. #6
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    Default Re: epoxy and foam compatibility

    Not sure what you mean by vacum the glass to the foam, please elaborate.Whats the cost of the plascore in 1" sheets?thanks for the help-Tony

  7. #7
    Commander Realgun's Avatar
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    Default Re: epoxy and foam compatibility

    Vacuum bagging is used to really clamp and saturate epoxy fiberglass to a substrate.It is used to make surfboards which are Foam blanks with a epoxy/glass outercoating. Very stiff for the weight.Hope this helps.

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