I am getting ready to build my first eps/epoxy board and I have a few questions. I have read and re-read pretty much every post in this forum and have certainly learned a lot. I have made about nine PU boards so far, and as a matter of fact, my first one was a recycled longboard blank which had some foam damage, that I remedied using spray foam in a can. Not knowing whether or not poly resin would “eat it up”, I decided to be safe and use epoxy resin. Though I haven’t used it since, I feel quite comfortable with the process of shaping as well as using the epoxy. I am in the process of getting my materials together for my first real go at epoxy and in particular eps foam. Like I mentioned earlier, I had read pretty much every post on here at least once, but now I fear almost to the point of overkill. I have loaded my head with so much info, that I have started to confuse myself. HAHA! I know I could look for the answers myself but I don’t know how much more of this I can take. Please, I need help with a few questions. First, I called a couple of foam suppliers (mainly insulation and dock building suppliers) in search of eps foam. I got a quote for a 4’x3’x16’ billet which was $688.00. Why so much? Also, at Home Depot and Lowes in my area (South Carolina) the only eps they have is 8’x4’x3/4", with a reflective skin. If I use these sheets and glue them to make a larger block, can I still use a hotwire setup to cut the rocker after glueing the panels together. How much should I expect to pay for a piece of eps large enough to hotwire a blank from? Also, at Lowes and Home Depot the only blue or pink foam they have are 4’x8’x3/4" ?RPS? sheets. What are these and have they been mentioned? Its just hard for me to be sure of what I need when my local stores don’t seem to have the products most often mentioned in this discussion, and they salespeople at both (though HD is a little better) stores have no clue about anything. Once again, sorry if you have already answered these questions a million times, but like I said these last few questions are the only thing standing between me and a few new boards. I am particularly interested in the ability to hot wire a glued setup. Thanks again for your years of inspiration and help.
$688 for a 16ft block is about average and you can get plenty of blanks out of it OR you can ask them to quote you for a smaller block like 8ft for probably half the price.
Dont think you can use the foam with the reflective skin and the pink and blue foam is XPS foam. You can use it but it may delaminate or break but it shapes nice.
The $688 sounds like quite a lot of money but when you look at it in terms of how many 8’ blanks that you can get out of it, it doesn’t seem that bad.
As for the “reflective skin” on the home depot foam, are you sure that’s not just some type of wrapping that you just peel off? The HD foam that I used in the past just had a plastic film stuck to it and it pulled right off.
Lots of guys on here have glued up the sheets and hotwired with no problems. Seems to go better if you use something like Gorilla Glue. I used the Elmers white glue and did have some problems shaping (minor problem).
Check around, you should be able to find the 4’x8’ sheets in something other than 3/4".
Good luck (and post pictures)
Stay away from pink & blue…some use it fine, but conventional wisdom is pointing in other directions.
Hotwires go fine through cured foaming polyurethane glue like Gorilla Glue, Elmer’s Ultimate, or Roo Glue - and those are also great for sticking EPS to other EPS.
The foil & plastics peel right off the Home Depot white foam.
With the Home Depot EPS, you’ll want triple 6 oz decks, double 6 bottoms, and glass-on fins. That foam is 1#/cu.ft. and is very soft, I think it has bigger beads than some of the other EPS foams, even in similar densities.
If you bought the 3’x4’x16’…and say no board was longer than 8’ or thicker than 3" and you were bending in your rocker with stringers or bagged-on skins (which works fine)…first cut is to 8’ lengths - 2 pieces. Second is to 2’ widths - 4 pieces. Each 2’x8’ is 36" tall - that’s 12 blanks…12 blanks x 4 pieces = 48 blanks for $688? $14.33 each sounds pretty dang good to me.
I used RooGlue clear to stick to slabs of EPS (4" X 12" X 60"). Couple weeks of sitting in my 60 degree garage plus 48 hours in my house and finding soft glue inside when thinning blank to foil. Good enough to hold together but still soft to fingernail pressure.
Applied glue w/ squeegee and NOT thick
If you are going to hotwire your rocker, then you’ll need about 6-8" per blank but Benny’s math at $30 a blank is still good.
Like said the plastic on the HD/LOWES insulfoam just peels off.
You should be able to custom order different sizes and densities from the HD special order desk. Some of the other EPS source threads indicate pretty reasonable prices on more manageable sized blocks that way.
If you plan ahead you can stack your rocker templates and get 2 blanks out of nearly the same amount of foam that you would need for 1 blank. example I can stack my 6’8" templates (similar to the 6’8"R) and get 2 blanks out of 7" thick foam.
If you are going to hotwire your rocker, then you’ll need about 6-8" per blank but Benny’s math at $30 a blank is still good.
Yep, or just cut 1 or 2 rockerless 6’ fish first, with the tails to the back end of the block…then you’ve got all the nose rocker room left in front of them for layering in up to 10 semi guns… 
Hi,
For a point of reference - I bought 2’x2’x8’ 1lb EPS block for $77. Got quite a few looks dirving the 75 mi to work and home with that on the top of my station wagon.
(I read posts daily - but don’t usually have much to add, so I never post. Thanks to the regulars for all the info you didn’t know you’ve given to me. Some day I’ll show the 2 boards I made (Clark) and the compsand I’m going to make this spring.)
George
Thanks for all of the info. Definitely helps, and gets my head straight. You’re right about the $688.00 block of EPS being not that bad of a deal. I just don’t have that much money to spend on foam right now. The company I talked to did say they would cut it to any dimension I wanted, I was just wondering if buying a bigger block would cost less (since you are buying in bulk) or more (maybe larger sizes are more difficult/costly to produce). I am going to HD tonight to ask about special orders and should have a quote in the morning from the dock building supplier. Meanwhile, I was installing a countertop today (I build concrete countertops) and their was a house being built next door. I went over and talked to the foreman to see if he had any leads on where or what was available in the area as far as foam goes. He ended up giving me two 4’x8’x1 1/2" blue XPS that they weren’t going to need, mainly because he (himself being a surfer) couldn’t believe what I was using it for. When I got home I glued it up with Gorilla Glue and will probably cut the rocker templates from 1/4" birch tonight. I am still getting the EPS (as it seems it is a better product for surfboards) but I am going to shape one from the XPS until the EPS gets here. Two things I was wondering. Seems stupid but has anyone developed any great methods for tracing/making a rocker/foil template from an existing board. Are the rocker profiles on the Clark Foam website (which is still up) accurate enough to enlarge and duplicate. Thanks again for your wisdom I will post some pics soon.
Are the rocker profiles on the Clark Foam website (which is still up) accurate enough to enlarge and duplicate. Thanks again for your wisdom I will post some pics soon.
clark cat says they are drawn to scale. 2 different scales I think depending if over or under some length. Catalog says in it somewhere.
May be a hard find in the archives but yes it talks about different ways to get rocker info from an existing board. One way is to put paper on a wall, attach a pencil to a rigid straight edge, turn board upside down next to the wall and slide straight edge along bottom of board thus drawing the curve on the wall/paper.
Then use thickness measurements to fill in the curve on the deck.
From the clark catalog you can use the measurement numbers and run a curve through the points with a flexy stick if you want to duplicate/aproximate one of the clark catalog blanks. If using EPS and hotwiring, then yo can also thin out your rocker guides to hotwire to a finished (or near finished) thickness. i.e. I took the 6’8"R and added a little nose flip in the last 3" and then reduced the thickness numbers when putting in the deck curve. I think I subtracted off all the thickness numbers so that I had a max thickness of 2 1/4".
just some ideas