Hey, i need to shape something out of foam (not surfboard related) and then laminate it with polyester resin.i was hoping to find somewhere to get a block of polyurethane foam or something similar that wont melt from the resin. In the past I have always just used the left overs from surboard blanks but at this time i do not have a big enough pieace. Can anyone point me into the right direction? I live in Orange County California. If all else fails, is there any way to seal the Home Depot foam from melting? Perhaps latex paint? Keep in mind, I am not concerned of how the foam ends up, i just need the glass to be the same shape and contour as I had originally shaped the foam. Any other suggestions as to how I can get a detailed shape out of glass?
can you tell us what you’re making , then we will have an idea what size foam you’re after, and someone here may then be able to tell you where to go …
ben
I am making various parts for my sportbike. (seat cowl, turn signals, etc…) I have no problem glueing small foam pieces before shaping. I think i may try the eps at home depot and just seal it with latex paint prior to glassing, unless i find some polyurethane.
In the USA, I bought some sheet polyurethane cores for making kiteboards here a few years ago:
http://www.generalplastics.com/products/index.php?
The product I used is called “Last A Foam”
I found that the home depot eps can be hard to shape because it’s so soft, but that material will be less expensive as long as you seal it well enough. If you are planning on just making a simple male mold that you will throw away later you could possibly seal it with melted parafin wax applied with a brush or roller.
Hey FredY,
have you considered the spray insulation from the Hardware store? You can make a base for your fairing out of cardboard, then spray the foam on the form.
After it cures hard, you could shape it. You can touch up with the spray foam as well. It glasses pretty well, be sure to brush a coat of pure resin before starting to laminate with glass; this stiffens the surface so you can bear down on it as needed. HTH.
Thats a great idea. I was actually at home depot earlier today looking at their polystyrene foam. Came to the conclusion that I would have to do ALOT of glueing to get it to stack up to the size I need for the seat cowl. Then I walked pass a can of expanding foam and thought if it could work or not. Do you have any brand names that you have used and where you got it? What do I need to look for on the can to confirm that it is compatible with polyester resin?
Thanks for the help guys
I got some from the ‘Homer’. I cannot remember the brand. I had someone tell me they used DAP and it withstood polyester as well. The density is not under control, and if it drops too low, even resin (or the working of the glass) seemed to make some spots “deflate”. I brushed my workpiece with lam resin (UV) and had no problems…
(my guess is that most all the spray insulations are water-based urethane like most surfboard blanks. The bad chemical is TDI (or MDI). These forms of isocyanate are likely to irritate your skin, so don’t get it on you! Pretty sure polyester will work with all these foams.)
…you could cover the parts of your bike with aluminum foil and have a cardboard backing and spray row-by-row until you get a good build up. After you shape it back with a steak knife, voids are unavoidable (no pun intended). I sprayed them and finished the shape.
Hardest part was waiting long enough for the foam to cure. Stuff gets gooey at the core.
Foam Sales and Marketing. Burbank, Ca. (818)-558-5717. You can get,at least, 4# in blocks 48"x48"x96". Maybe bigger, can’t remember.
You may also want to try shaping it out of EPS and plastering over it. Let the plaster dry out, which will happen naturally or you can speed it up with a fan blowing on it to “pull” the moisture out. Seal the plaster with 3-4 coats of orange flake shelac cut with denatured alcohol. Then you can hit it with a clear lacquer and wax it up with release agent/pva. I live in the OC so pm me if you need some guidance. Ive carved/sculpted lotsa big foam stuff for Disney, Toyota, etc.
thanks, Ive started to use the foam spray and ill see how it turns out. Im glad I have other options if this doesnt work
Sorry I came on so late…
I made the fairing plugs for the watercooled TZ-250 Yamahas, their square sided small seats, later the bigger faired seats.
You can buy gallons of two part polyurethane foam from Tap Plastics, kinda light brown like old production windsurf boards.
A gallon of A mixed with gallon of B gives you app. 4’x4’x6’, inside a cardboard box.
Easily shaped with anything rough (body tool the best, with round cutting blade), foam tends to be slightly inconsistent, as you have to pour several layers to get over 16" thick. Each is good around 8" thickness…any more, you get varying densities.
That reminds me of some guys I knew that got burned by a co-worker and as retribution pryed open his son roof, mixed several gallons of A/B poly foam and poured it in. The repair shop couldn’t even get the doors open. They had to scrap the whole car.
HAAA!!! that’s great! imagine dropping the stuff on a riot or battle or something. Everyone would be standing there stuck to one another.