neighbor asked me to “help” him shape a blank he got for x-mas. said …sure. turns out the blank is epoxy. never shaped one before.
i advised him to take the blank back to the shop it came from and pay the shaper there to do the shape and to let him watch. but noooooo. also told him i have never glassed with epoxy and will NOT “help” him glass the finished blank.
so, will the tools i use on poly blanks work as well on epoxy? particularly concerned about planers. don’t want to lay the planer on it and see huge chunks of epoxy start flying about. don’t have a shaping barrel on either planer and not planning on getting one for this project.
any advice from epoxy experienced will be greatly appreciated.
Yeah, well the main difference is in the structure of the foam. Instead of a solid foam with tiny little bubbles as with polyurethane, with EPS you will have little beads that are fused together in the manufacturing process.
The basic process is the same but it is more difficult to get a perfectly smooth surface. If you use a super coarse sanding pad or surform you might encounter beads tearing out. The finished surface generally has a tendency to be slightly 'pebbly' in texture.
Depending on the bead structure and foam density you might consider giving the shaped blank a surface treatment sometimes referred to as "Spackling", "Priming", or "Sealing" before glassing. Some treatments used include DAP Fast&Final Spackle, Epoxy resin mixed with microballoons, or a polyurethane sealer coat. Any of these will help smooth/seal the surface and prevent too much epoxy resin from seeping in to the foam as you glass.
As you've probably guessed, do not use polyester resin on your blank. Without a perfect barrier/seal coat, the foam will melt in contact with polyester. The correct choice would be epoxy or a urethane resin like Resin-X. I have heard of a new urethane resin used as a barrier/seal coat under polyester but can't recommend as I haven't tried it myself. I have tried a urethane barrier/seal coat under epoxy on test panels and it worked quite well... stronger than epoxy by itself.
A lot of legit advice from some very legit sources mixed in with a little bit of humor and this is how you respond?! You are indeed a special individual.
I guess these people taking time out of their busy lives to try to help educate you deserves no respect.
Ask your question at surfermag and see what kind of response you get there.
Next time use the search function before posting a dumba$$ question… or appreciate the honest and informative responses that you get
Just glass the board with polyester, it will work great.
If you do decide to help him glass it with epoxy, which is not hard at all, keep in mind (or pass on to him):
-** Mix ratio**: extremely important. Get it as close as possible per the instructions for that particular epoxy brand. Its not like polyester where you can kick it faster or slower by adjusting the amount of catalyst used. If you mess with the ratio, it wont cure right. Also beware that the mix ratio is not the same if you measure by weight or by volume.
You dont need to work epoxy into the cloth like polyester resin, simply use your squeegee to move it to where you want it and let it soak in on its own, come back and get the dry spots after.
What does supercilious mean? Man, people seem to be sensitive lately. Is it the economy? Earthquakes? What? Mike D. and chrisp answer in the usual helpful way. Sammy gives it his usual blunt humor. I hope peterg’s friend comes on for help. I don’t think he needs peterg. Mike
i ask a question on the shaping and building forum where those in the
know provide assistance to those who are not so much in the know.
and what i get is a ration of shit because i use the term epoxy instead of eps.
anal retentive supercillious petty bastards.
go fuck yourselves.
i’m out of here.‘’
I can not count how many times, when I worked in a retail surfshop, I calmly tried to explain the differences to a customer that was looking for “a epoxy board, NOT a fiberglass board” and pretty much got told the same thing. Thats why I have gone back to the “backyard”. In the store I had to put up with it or some 19yr old manager would tell the owner, who did not know or care the difference just sell “what they want” I was disagreeing with a customer, again. Now its my yard and I would be telling you “out of here” with that attitude.
First off, I doubt your blank is ''epoxy''. You probably mean polystyrene, which will use epoxy resin in the lamination of skin. Polystyrene surfboard blanks come in two forms, extruded (XPS) and expanded (EPS).Your friend's blank is likely EPS.
No problem using planer, and grit drums aren't needed. Coarse paper (36-40 grit) blends planer work nicely. Forget the drywall screen used on PU rails, sandpaper works much better on EPS.
I shape EPS only now, and I couldn't imagine going back to PU. Once you're accustomed to EPS, it is much easier.
Epoxy is a kind of resin. the blank, i’m assuming, is EPS…
there’s TONS of info here on Sways about shaping EPS. the EPS that i’ve shaped (Marko and White Hot) seemed pretty easy to shape to me. i’ve only shaped one PU board tho… i use the Clark Hitachi (regular blades, no barrel), sanding blocks, and a hand plane for the stringer. i couldn’t get a Sureform to work that great with EPS. this: http://www.foamez.com/pleskunas-sanding-block-3-p-182.html works great on EPS in place of the sureform but, is not necessary… your post kinda comes across anti “epoxy” but you may be surprised, it’s not that difficult to work with but, especially when glassing, you have to follow the directions: http://www2.swaylocks.com/node/1012166 . again, lot’s of info in the archives