Example of polyurethane foam car "sculpting"

[Blue07CivicEX]

Hokay, so! I bought foam, sculpting tools, paint (black figure two tone black and blue looks ok) and fiberglass making materials! I believe I have everything I need, now comes question one, I am going to make the foam molds for the front of the civic but how much setup time does it take before i can take them out of they're home without the shape changing? I saw that curing time was 8hrs but do I have to leave my car sitting still with foam all over the front for 8hrs or is it like 1-2?

[cfg83]

Hello -

Here's a question for a foam bumper mod. Can I apply a thin (clear?) plastic sheet between the bumper and the foam so that the mod is "removeable" after I apply it? The idea is, I want to be able to revert back to stock if I don't like the mod. For instance, on the nose of my car, I would like to preserve the paint job on the bumper if I don't like how it comes out. The bumper would be the "mold" for the foam to rest on.

If yes, then what kind of plastic sheet would you suggest?

CarloSW2

[Blue07CivicEX]

I plan on using painters tap on the paint to protect against the foam sticking to the car, but then what if the foam sticks to the tape you ask? I have not a clue, I'll find out when I try it :-D. you might be able to do it with something along the lines of a trash bag cut and taped where you need it to be. I am not sure if polyurethane foam will eat a plastic trashbag or not, I'm not a ChemE I'm an EE.

[3wheeled]

I don't recall polyurethane foam melting anything in using it.
I do remember this...it sticks to EVERYTHING!
Gorilla Glue is basically polyurethane.

I would try making the part out of urethane board. They sell it in 1/2" and 1" thick 4'X8' panels. It is covered in aluminum foil so that has to be pealed off.

Once you have your perfect plug. downsize it about 1/8" on the front and sides. Then cover it completely in 1-2 layers of fiberglass and polyester resin.
Of course it wont be perfect but then you can sand it down and build it up where needed with auto filler putty. Eventually it will be what you want and will fit perfectly.

[Blue07CivicEX]

Do you remember what the amount of time before it was removable from the mold was?

[3wheeled]

I have never used it the way you are planning but the foam takes a few hours to completely cure. It "grows" over time. After 4-5 hours it is good to move on with.

[Blue07CivicEX]

Excellent! Thanks for the help :-) I'll post pics of my sculpture tonight when I start. Waiting till I head to the g/f's place.

[trikkonceptz]

You can use blue painters tape to protect the original surface then cover the surface in aluminum foil, which will obviously not stick to the blue tape and therefore release when you are done foaming. Tape the aluminum foil down where it will not stick or conform on its own ...

[Blue07CivicEX]

Alrighty, foam is setting, I used two cans of foam and did the fogs, bottom grill, and top grill, I covered EVERYTHING with painters tape to be able to peel off once it's cured, had some trouble with the foam sliding off the paint but found a fix for that (I hope) I have pics coming a little later tonight of the taped up car and the foamed car, if the molds come out ok I will 'glass them and paint them, if not i'll buy more $5 foam and $10 tape and give it another go!

[COMP]

Originally Posted by 3wheeled

My kids and I have been building a 3-wheel car from the ground up. We have built the body out of urethane boards purchased from a local lumber yard. Glued the panels together with the spray urethane foam (Home Depot) and then covered both sides of the body with 2 layers of fiberglass and polyester resin. It is quite a job but a lot of fun for sure! Here are some pictures over the years...

http://picasaweb.google.com/stinger3wheel/Stinger