Ha! Awesome find!
..."a ride that's really fast!", ...Twist, turn, spin like wild!", "...what a ride!" That's exactly what the AtomIQ is!

Trying to repair my windsup and decided to make my own filler which ironically melted the styrofoam inside the board and now I have a trice as big a cavity to fill-approximately the size of an egg. At least now I'm sure there is no water left inside.
What fillers do you guys use for this job? Is this urethane foam OK ?
www.shopmaninc.com/foam.html
Do you close the hole before the foam expands ? Any tips appreciated!

Ady wrote:

The Board Lady > Repair Materials www.boardlady.com/repairmenu.htm

"To reinforce fractured EPS foam, I use a Marine Urethane foam by Evercoat. As opposed to the stuff from the hardware store that comes in a spray can, this foam does set up hard."

"For filling, when I really, truly do not want to have to deal with bubbles, I use an Epoxy filler by Interlux, "VC Watertite"

Ady,

Melting Foam on a board repair is usually caused be the "heat" given off by the Epoxy when it "Goes-Off". The quicker the set time or, the more epoxy resin that is used, the more heat (BTUs) is given off (e.g., 5 minute epoxy vs. four hour epoxy). And, if the epoxy resin is surrounded by an insulating foam (which is a thermal insulator) there is little to no way for the heat to escape.

For repairing a significant void in the foam it's best to use another piece of foam as a plug. A product called "Divinycell" (foam) is both light and strong for this application. It's important to have the foam plug fit tightly in the hole to minimize the amount of epoxy resin used. Less epoxy resin also reduces the BTU's (heat). After the epoxy cures, fair the foam plug to shape. Finally lay two to three layers of fiberglass cloth and finish the surface.

There are several examples of this repair strategy on the "Board Lady" website that Reid has posted.
(www.boardlady.com/repairmenu.htm)

Doug

So, the idea is to stuff pieces of solid foam like styrofoam or divinicell covered in epoxy inside the cavity? Am I reading this right? This was my idea also at first, but instead of epoxy, I poured a little of Barge cement glue which I had left over from the EVA foam board-nose protectors that Ive installed on my first boards. I was sure the glue would be safe on the styrofoam, but it melted the stuff immediately on contact. By the time I was able to clean it away the tip of a tumb size cavity became an egg size. Anyway I filled it up yesterday with Loctite expanding foam from an aerosol can and today after cutting off the excess it doesn't look overly porous inside, but probably still far cry from the professional. After sanding it a bit I covered the hole with the white 2 part marine epoxy that I had lying around. I will assess the result tonight when I get back home and probably will sand and put some more of the white epoxy forgoing the glass cloth for which the epoxy is too thick to do a proper adhesion. This is a temporary fix to get me through the season and come winter if there is more damage to be fixed across my boards I'll order the right stuff -foam, epoxy and cloth to be able to do job right. No time for that now, Wednesday looks good for some wave riding over on the Michigan side

Yow !
The primary reducer in Barge cent is Toluene. Toluene is more volatile than Xylene, Mek and, Acetone..
It was probably the main culprit in melting the foam.

I've used Divinycell but have never tried Styrofoam. Divinycell is super stiff and so hard that it's hard to squeeze a half inch thick piece between thumb and forefinger to even put a dent in it. Great stuff to use on a deck repair for soft heel dents..... The tight 'wedged in fit' of a piece of repair foam into a board should require just a minimal skim film coating of epoxy. And, a slow cure epoxy would also be best...

I've seen successful expansion foam repair videos on the 'net' as well as on the Board Lady website.... looking forward to the update....

My attempt at fixing the windsup has been quite frustrating so far, but it was expected doing it with department store leftover materials. I brought it to operational condition and I'm going to take it with me tomorrow wherever I go sailing, but it needs some more finishing work so I ordered proper epoxy, urethane foam and q-cell filling from "US composites". I'll just laminate with a layer or two of glass cloth and epoxy over the area where the hole has been and paint it over, but after realizing how fragile the poor thing is I decided to stock on materials, because they'll be more repairs now that I'm using it in waves. Turns out my converted SUP has a single skin construction. Pretty much like packaging paper soaked in epoxy, wrapped around the styrofoam and painted fancy. No Divinycell sandwich or any kind of reinforcement anywhere. I guess that's the way they make the SUPs to save weight and cost -the cheap way Any modern windsurfing boards, even the light wind kind are made much stronger, but of course they have to withstand a lot more abuse being the planing kind of boards. I'll need to be more careful around the shore break with it , now that I know how what is it made of.

I complain every time I ding my Atom and my wife keeps telling me "it's not a museum piece, at least it shows you are using it"! She has no compassion, ha!
The day there's a windsurf brand that decides to add a layer of impact-resistance Kevlar around the rails and nose, I'll buy their board unconditionally! But I think I can keep waiting: The fact that this equipment is this fragile is by design and it's called programmed obsolescence. ...Got to keep buying new boards regularly or some will go out of business!
Ady, hope your fix will hold!

Ha! A fitting greeting for windsurfers: "May your fix hold!" Amen, brother!