Chicks dig me, 'cuz...

I shape pink foam.

Ok, this is a concept "coloring" of my final board - it'll be built from common "big box store" xps insulation foam. Ownes-corning pink for the core and Dow blue styrofoam for the rails. I'm combining my previous perimeter stringer work that will separate the two color foams.

Dang bifocals! does anybody else see two?

Now, as I was planning this I realized that this project would also allow folks that WANTED to test out wakesurfing but didn't want to ante up the $300 minimum or $600 for a custom board, the opportunity to build a board for maybe $40. It won't perform like the high end boards, but it should be MORE than adequate to get you hooked.

In most parts of the country (CA and TX are notable exceptions) you can find either Dow Blue Styrofoam insulation or the Ownes-Corning Formular insulation boards. They are typically available in a convienent 2' x 8' size. The Formular 25 is an approximate 2# density foam. It will easily withstand someone standing on it in the water.

The board is just that - it's a board and very flat.

THe final build will be a perimeter stringer, but the "do I like it?" (DILI?) board will just stop at the glue up of the wooden stringer material. Now I chose the 1.5" thick pink core, I'll shape this down for my final product, but the DILI? board won't require any thinning.

I had a blank that I traced onto this pink foam, but realistically for the DILI? board you can borrow some dimensions from your local pro shop. Figure a max width of 20" - 22" and a length from 4'6" to 5'6". Then connect the dots gracefully.

XPS foam will hotwire. The Owens-Corning pink melts much better than the Dow Blue. I've read that mostly this is due to the Dow Blue having considerably more dirt in it. Both foam will melt and form beads of the melted foam that needs some minor hand attention after the cut.

For my work, I just used a jigsaw and sanding block - easily available to most DIYers.

The outline, above doesn't need to be perfect for the DILI? board - however, remember the closer to symetrical, the better it will perform.

Now the final step is to fashion two stringers that will hold the rocker. The rocker is the curve (from nose to tail) of the board looking at it sideways. I made these just slightly thinner than the 1.5" thick core. I used some scrape door skin - you'll want to use some very thin wood - Basswood would be great - 1/8" ply or a Luan door skin will work also. I had a specific rocker in mind, give youseself a minimum of 2" of nose rocker and keep that in the first 18" of the nose. You can free hand this, just be sure that you make two identical stringers.

I used epoxy to glue my stringers to the core, Gorilla Glue or equivalent would work also. A liberal application to both sides if you use epoxy is needed. The XPS is a very tight bead, and being a closed cell foam there will be almost no penetration of epoxy into the foam as with EPS.

I also used a bag to suction everything down, but there is a cheap alternative for the DILI? option.

The stringer material, if you've selected a fairly thin wood, will bend easily and can be held in place with a few different options. Tightly wound saran wrap - as if you were wrapping the board up, or bicycle tire inner tubes slit so that they hug the nose can be stretched and will hold the wood against the foam. Dennis also has told me about pond liner material - Bro? I'm not quite sure how that would work.

Next you need to put some rocker in the board until the epoxy/glue dries. You'll want to OVER bend your rocker because the 2# foam board is pretty stiff and will rebound some after you let everything go. Figure that you'll lose about 1/3" of your rocker. Bend 3" to net a 2" rocker.

A few saw horses and an approrpriate weight will give you the bend you need.

When the epoxy dries, that will hold the rocker well enough for the DILI? board. The XPS being closed cell won't suck any water, so principally you can surf it after the epoxy dries. You don't need to glass it or do anything else. If you think you might like to get more than an afternoon's use out of it, I'd paint the wood so that it doesn't soak up water and drill and attach a set of old wakeboard fins. You'll no doubt have to find some longer screws at your local ACE Hardware...but even if you bought everything here is my list and total cost:

1) Foam #13.50
2) Door Skin / equivalent $15.00
3) Slow Epoxy (get 2) $12.00
4) Bicycle tubes $3.00
5) 2 - 2" long 1/4-20 screws $.50
6) Wakeboard fin - STEAL IT! $0.00

Check my math - but I think that's $44.00

Don't know anything about pond liners. The best thing without a bag is the inner tube. Car or truck tire will give longer bands when split.

I must have heard you say it when I was feverish! Notice when I came out of the fever, I create a pink and blue board!

Did you find the blue foam?

Just a sample, not enough to do the whole board. Can you source me some? Or know where I can grab it in Stockton? As a minimum, I need a piece 5' long, 1.5" thick and maybe 6" wide.

These people should have exactly what you need. http://pacificsupply.paccoast.com/default.asp?pageID=264&city=Stockton&stateID=13 Let me know if they don't.

Thank you, sir!

Jeff what do you mean final build, are done building boards?

Jeff -- does the $44 include resin and fiberglass? Maybe I missed that?

Here's my pink foam prototype. I shaped this last summer but never got around to glassing it up. The foam is really, really easy to shape compared to EPS, but from what I understand -- to prevent delams you are supposed to rough it up a bit before glassing to let the resin soak into the nooks and crannies like butter on a Thomas' English Muffin. **

Dow blue is readily available at Lowes. Pink is available at HomeDpt -- although they are only available in 3/4in thick sheets here in Austin. I got some thicker sheets from a guy who does RC airplane wings.





** Disclosure: I'm not affiliated with Thomas' English Muffins, Lowes or HD, although I do make custom wakesurfers.

LOL - I loved the disclaimer, Matt. On my DILI? board - it wouldn't be glassed, just left at that stage - not intended to be anything other than a DIY'er's test on either do I like building them, or do I like the whole surfing thing. It won't last more than a day or two at that stage...so the $44 is without any 'glass.

Out in California, at least here in the South of Sacramento area...the big box stores don't carry Dow at all and only Home Depot has Ownes-Corning.

Hey Bob, not to worry - I have shaping in my blood...I'm sure I'll have more crazy projects...I wasn't clear, I was just referring to the second and final stage of this project.

Hey Ed, how are things in the gator state? Always feel free to share my projects, I'm in it to: "share the stoke" I actually had a young shaper tell me that and I had to ask James what it meant. What is he sharing with me? Is it communicable?

As I continue with the project I'll elaborate on the issues with XPS as a source of surfcraft foam.

There are a few different types of foams that are used in surfboard construction. Two that get confused by garage hacks like myself are of the polystyrene family. You typically see them referred to as EPS or XPS (sometimes EXPS). To further confuse the issue - Styrofoam is actually a Dow trade name that refers to their blue colored XPS foam as shown in the first picture above, whereas most people incorrectly call the beaded EPS foam found in coffee cups styrofoam.

One of the issues with garden variety XPS for use in surfcraft is that the process in which it is made traps, what is referred to as, "blowing agent" inside the cells of the foam. I believe that the majority of XPS foam is manufactured using Pentane gas as the blowing agent.

As the board is ridden and these small cells are ruptured the blowing agent gas is released, (and let's assume it's Pentane) but typically it is underneath a final 'glass lamination. When that Pentane is heated, as would normally be the case out behind the boat say...in July the Pentane expands and causes a delamination. Another issue with the manufacture of garden-variety XPS is that it is copolymorized with polyethelene which almost NOTHING sticks to. There are some creative ways to vent - a bazillion tiny holes all over the 'glass is one way.

My expectation on this board is that it will delaminate after a few rides, and I'll junk it. I'm interested in how the XPS responds in comparison to EPS and Polyurethane of the same density.

Currently Dow manufactures a variation of the XPS that "supposedly" doesn't have these issues, but it's a bit pricey...so I thought I would give this test a shot before investing in the more expensive stuff.

I finally scored some Dow blue Styrofoam. My buddy Dennis found it up in Rancho Cordova...literally there wasn't a single retailer that carried the stuff in the greater Stockton area.

cool Jeff -- how thick is that sheet?

Hey Matt - that is 2" thick. I'm just going to use the above board for the rails on the pink interior blank. I only need 1.5 inches on each side.

Is the Dow blue readily available in TX or did you have to hunt down your material? When I called Dow directly to find a supplier in my area they couldn't! Although they found two suppliers that were 800 miles away

Yes Jeff -- It is available at Lowes here in Austin. However - only 3/4" thick. I think there is a Dow plant near houston.

Pink is available at Home Depot - again 3/4".

Interestingly enough the pink owens corning is significantly stiffer than the Dow Styro. I had originally thought that the Styrofoam would be as stiff as the pink Formular. This changed the way I dealt with the rails. My original idea was to cut and shape the rails to fit. However, seeing how flexible it is I just rough cut a 2 x 2 section to make the rails. It's flexible enough that when I bag the strips, it will bend both vertical and horizontal. The strips have factory finish on three sides, os the bottom and inside that attachs to the stringers are squared up.

I angled the nose so that when I apply a vacuum the rails segments will match.

My vacuum bag has a hole in it somewhere, so I need to swap that out. Hopefully I'll get this in the bag tomorrow night.

Finally got my seal fixed...although the bag sprung a leak and I can't pull a vacuum of 3 inches...we'll see if it's enough to keep everything in place.