Using latex paint to glue eps blank

[fumaster]

Watched this guy building a SUP using building insulation to make a blank. He used latex paint to fuse panels together. It seems to work, and using flat white paint, glue lines are less noticeable. Wondering if anyone has used this method?

[PonoBill]

Clever, but it seems like a potentially heavy solution. I use a light spray of 3M contact cement. You don't need much adhesive, just enough to hold things together through the shaping process until you get the glass on. I'd rather get a big block and cut blanks from it, but I can see how this would be useful if you're using what you can get. I watched the video. The latex paint thing isn't the only unusual part. It will be interesting to see what other folks think.

[Vancouver_foiler]

Ponò, didn't you find that spray glue disolved the EPS?

[TallDude]

He did a decent DIY job. Very systematic about the way he approaches his work. The shape is not a shape. That what you call 'Box Rails' with a little turn down. The tail was so thick it would not turn well. Plus no single or double concave on the bottom. Really basic. As far as the glue, it worked. 1.5lbs foam gives you a heavier board to start with anyway. The fin boxes won't last and it will leak around the handle after a few outings.

[Stew]

The fin boxes won't last and it will leak around the handle after a few outings.

Why is that? Is it because of the lack of extra glass lining the pocket?

[Dontsink]

He did a decent DIY job. Very systematic about the way he approaches his work. The shape is not a shape. That what you call 'Box Rails' with a little turn down. The tail was so thick it would not turn well. Plus no single or double concave on the bottom. Really basic. As far as the glue, it worked. 1.5lbs foam gives you a heavier board to start with anyway. The fin boxes won't last and it will leak around the handle after a few outings.

Usual EPS for longboards is 2lbs.
Why is 1.5lbs heavier?, needs more skin layers?.

[TallDude]

The fin boxes won't last and it will leak around the handle after a few outings.

Why is that? Is it because of the lack of extra glass lining the pocket?

In EPS 1# or 1.5# the fin boxes need to be set into a cassette of HD foam ( tow-in foam PU, or PVC / divinycell). You don't ever need to use 2# EPS, the board will be too heavy. Even 1.5# is too heavy for any performance surf sup or race board. 1# with PVC wrap and HD foam cassettes is the best. What kind of fabric is based on the use. CF for long race boards, makes them stiff. S- Glass (or E glass) with CF stringers and rails lets the board flex and spring.
Glass lining the pocket is a plus. It's a must with no HD foam cassette.

[TallDude]

He did a decent DIY job. Very systematic about the way he approaches his work. The shape is not a shape. That what you call 'Box Rails' with a little turn down. The tail was so thick it would not turn well. Plus no single or double concave on the bottom. Really basic. As far as the glue, it worked. 1.5lbs foam gives you a heavier board to start with anyway. The fin boxes won't last and it will leak around the handle after a few outings.

Usual EPS for longboards is 2lbs.
Why is 1.5lbs heavier?, needs more skin layers?.

I've never seen anyone make a board with 2lbs EPS. Maybe in the early years of SUP. The first board I shaped was 1.5lbs EPS with a wood stringer. 1.5lbs is easier to hand shape than 1lbs, be cause the 1lbs EPS beads are larger and they sort of flake off leaving bigger pits in the surface. As for most surfing longboards, they are still made out of PU foam which is much more dense (heavy). It's around 3lbs /sf

[Stew]

Thanks.

[PonoBill]

Ponò, didn't you find that spray glue disolved the EPS?

No. I mist it on lightly.  But even in heavier applications, I haven't seen that.