eps block or laminate

General Discussion
1

Should I go with a block of eps or would it be ok to laminate 3 x 20mm sheets to roughly near the bottom rocker

Regards Mike

2

I would say that depends whether you want to get into hot wire cutting or not. Taking down a square block to a rocker curve would be a bear with just a planer, and might not give a good result. The glue up procedure is fine, might take a little more effort per board, but is good for the homebuilder with limited resources who doesn’t mind spending more time. I would say the hotwire setup would pay off with multiple boards, you could get a big block and keep peeling off blanks on demand…

wells

3

Advantage of sheets is easy rocker addition. When the glue sets, it takes the rocker you set the first sheet with. Easy, economic, and little wasted material. And you automatically come out with horizontal stringers (the glue used).

4

Lee and Wells

thanks guys It will just be a one off for me

I can only get up to 100mm here

I fig if I laminate it using 20mm then put it on my profile table to fine tune it

Regards Mike

5

IMHO the glue lines are a #%¤#* to shape. You may blow out a chunk of foam with the planer if your unlucky. Much depends of the glue used I guess, but I will not have any gluelines except for at the stringer EVER AGAIN if I can help it. A hotwire cutter is real easy to make and a car battery or a charger will provide enough power for it. It does save ALOT of work.

regards,

Håvard

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6

Haavard

Thanks for the info ,stupid me I had not even considared the glue lines and and chiping

I might try an experiment or two A)with the hotwire and B)with the router and glues

Thanks Mike

7

Glue lines…when you get there, slow down, use the surfform, then continue on your merry way.

Some guys think horizontal stringers are better on epoxy boards to keep them from twisting. They are NOT hard to shape.

All styro boards, you have to paint anyways, opaque, so it hides the imperfections in the shape. Heck, some guys stiple the shape for more resin retention. Little gouges caused by the glue is just that.

8

hello.

i just did a board out of glued up eps. i used spay glue (3M #77) and it worked great for me. the hotwire cut right throught it no problem and i didn’t have any tear out or whatever. the eps that I used (about 1lb density) was so easy to shape and sand that after the close tollarance hotwire cutout i just used 40 grit paper to shape the whole thing… one thing i will do differently next time is spray mount my hotwire rocker templets to the sides of the slab prior to cutting. i simply screwed them in last time and the flex of the the foam caused problems… be sure to preseal the blank…

good luck.

9

I just did eps (1# density bead board) glue line tests using Titebond II, Elmer’s white, 3M-77, 3m-90, and RR epoxy. I had NO problem power planing, surforming, or sanding the glue lines. FWIW, the RR epoxy was the very clear winner - lighter, incredibly strong, terrific bond, added stiffness (definitely like a stringer), way faster process since epoxy is a chemical cure not an air cure. YMMV.