Noodle, Peter Rjik - Bouyancy Comparison - EPS Vs. Poly

I posted yesterday that I just got my first epoxy blank. I wanted to make a fishy board something like 6’2" 14x20x15 - 2 3/4 thick. This is based on what I have ridden and made in the past (poly). When I picked up the epoxy blank it looked a little thinner than what I wanted but I was stoaked to get something new, and I was too busy thinking of questons to ask the guy about spackle and glassing and forgot about the thickness until I took my calipers to it at home. The blank is 6’ 6 1/2" bottom length x 24" wide and 2 1/2" thick. Flat rocker, which is what I wanted when I ordered a fish blank (4" nose rocker and 1" tail rocker). My question, at 200 lbs. I don’t think a 6’ 2" is going to float me, but this is based on poly boards in the past. How bouyant is this epoxy foam? Do you think I would notice a difference between the float of a 2 3/4" poly vs. 2 1/2" eps (with the same dimensions) ? If there is not big difference in float I am thinking I should make an egg out of it. Maybe a eggy shape 6’ 5" x 21" wide with a full nose and full rounded pin and boxy rails? I have to surf a lot of wind swell, and I want something that floats. I could take the blank back, but I would have to wait another 2 weeks, and having never worked with this stuff I don’t even know if the difference in thickness is even an issue.

I posted yesterday that I just got my first epoxy blank. I wanted to make > a fishy board something like 6’2" 14x20x15 - 2 3/4 thick. This is > based on what I have ridden and made in the past (poly). When I picked up > the epoxy blank it looked a little thinner than what I wanted but I was > stoaked to get something new, and I was too busy thinking of questons to > ask the guy about spackle and glassing and forgot about the thickness > until I took my calipers to it at home. The blank is 6’ 6 1/2" bottom > length x 24" wide and 2 1/2" thick. Flat rocker, which is what I > wanted when I ordered a fish blank (4" nose rocker and 1" tail > rocker).>>> My question, at 200 lbs. I don’t think a 6’ 2" is going to float me, > but this is based on poly boards in the past. How bouyant is this epoxy > foam? Do you think I would notice a difference between the float of a 2 > 3/4" poly vs. 2 1/2" eps (with the same dimensions) ? If there > is not big difference in float I am thinking I should make an egg out of > it. Maybe a eggy shape 6’ 5" x 21" wide with a full nose and > full rounded pin and boxy rails? I have to surf a lot of wind swell, and I > want something that floats. I could take the blank back, but I would have > to wait another 2 weeks, and having never worked with this stuff I don’t > even know if the difference in thickness is even an issue. Mike, I normally ride 7’2-7’6 hybrids, I shaped myself a 6’10 outta EPS. Kept it as thick as possible its a little over 2.5. Went wide at 22". Still wasn’t sure it would float me. I like a thick board. Anyway, finally got it out in some fairly lined up,slow beach break at about waist high. It seem to paddle ok, but I turned on the first wave and didn’t really think it would catch it, well it did. EPS floats! Its gotta different feel when riding also. I say go with the fishy shape but take it up to the 6’5 size. If you are in good shape and strong paddler the 6’2 may go, but it might be a streach. You can defintely go thinner with eps than poly for the same size board. Good luck. ed

Thanks for the info. I have always heard that the float was much better but have not had a real basis for comparison.

I posted yesterday that I just got my first epoxy blank. I wanted to make > a fishy board something like 6’2" 14x20x15 - 2 3/4 thick. This is > based on what I have ridden and made in the past (poly). When I picked up > the epoxy blank it looked a little thinner than what I wanted but I was > stoaked to get something new, and I was too busy thinking of questons to > ask the guy about spackle and glassing and forgot about the thickness > until I took my calipers to it at home. The blank is 6’ 6 1/2" bottom > length x 24" wide and 2 1/2" thick. Flat rocker, which is what I > wanted when I ordered a fish blank (4" nose rocker and 1" tail > rocker).>>> My question, at 200 lbs. I don’t think a 6’ 2" is going to float me, > but this is based on poly boards in the past. How bouyant is this epoxy > foam? Do you think I would notice a difference between the float of a 2 > 3/4" poly vs. 2 1/2" eps (with the same dimensions) ? If there > is not big difference in float I am thinking I should make an egg out of > it. Maybe a eggy shape 6’ 5" x 21" wide with a full nose and > full rounded pin and boxy rails? I have to surf a lot of wind swell, and I > want something that floats. I could take the blank back, but I would have > to wait another 2 weeks, and having never worked with this stuff I don’t > even know if the difference in thickness is even an issue. Truth bites. How much board you “need” for floatation depends on your experience and expectations. One man’s rock is another man’s water wing. Surfboard/rider floatation depend on two things, weight and volume. Built light, an epoxy/EPS shortboard will be about a pound lighter than a poly board. One pound represents 10 percent of board weight, but represents 0.04 percent of board and rider weight. You could gain the same advantage by skipping a meal. I think a 6-2 shortboard is too short for most 200 lb riders. I would be looking at maxing out the board length, and width. I would also make nose, tail and rails as full as possible. You can max out all these dimensions in an egg shape or a fish shape. I can give you some dimensions after you decide a little closer. My wife complains about sizes of new women’s cloths. The expensive clothes quote sizes numbered smaller that the same sizes of cheaper clothes. They do it so that the “full figured” gals with lots of money can pay to think of themselves as petit. We need standards!

Thanks for the info. I have always heard that the float was much better > but have not had a real basis for comparison. There’s a difference in floatation between EPS and Styrofoam, for styrofoam I would use the same numbers as on a clark blank, for EPS you can get away with less volume. It all depends on your surfing ability/condition, if youre not sure than add a little lenght/thicknes/wide. Looking at your numbers I think for EPS something like 14.5/21,5/17 on a 6.4 lenght, keep some volume in the rails. Take a look at the site from Steve Brom and look at the site profile of his shapes. Good luck shaping. Peter Rijk.

There’s a difference in floatation between EPS and Styrofoam, for > styrofoam I would use the same numbers as on a clark blank, for EPS you > can get away with less volume. It all depends on your surfing > ability/condition, if youre not sure than add a little > lenght/thicknes/wide. Looking at your numbers I think for EPS something > like 14.5/21,5/17 on a 6.4 lenght, keep some volume in the rails. Take a > look at the site from Steve Brom and look at the site profile of his > shapes.>>> Good luck shaping.>>> Peter Rijk. ( FOR A FISH )