# expanda foam



## 1woma (Apr 29, 2011)

Just a quick question.....can i use the heat gun like i can on the styrofoam?


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## Virides (Apr 29, 2011)

Wiki for Styrofoam:

Polystyrene is a thermoplastic substance, which is in solid (glassy) state at room temperature, but flows if heated above its glass transition temperature (for molding or extrusion), and becomes solid again when cooled. Pure solid polystyrene is a colorless, hard plastic with limited flexibility. It can be cast into molds with fine detail. Polystyrene can be transparent or can be made to take on various colors.

Wiki for Expanda Foam (Polyurethane):


A *polyurethane* (IUPAC abbreviation *PUR*, but commonly abbreviated *PU*) is any polymer consisting of a chain of organic units joined by urethane (carbamate) links. Polyurethane polymers are formed through step-growth polymerization by reacting a monomer containing at least two isocyanate functional groups with another monomer containing at least two hydroxyl (alcohol) groups in the presence of a catalyst.

After some reading, it seems to be highly flamable and not have the same characteristics as Styrofoam (Polystyrene).

You could try it on a small part, however by the sounds of it, you will experience a very chaotic and dangerous flammability.


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## J-A-X (Apr 29, 2011)

a hacksaw blade is your best friend when working with foam, either the 'normal' foam or expanda foam, I use a butane torch on the normal foam to dissolve the saw marks, I did try the torch on the expanda foam, and it didnt do much of anything really, but i'm not heavy handed with the torch, i only ever give it a quick wave over the surface, Going by what Virides has just explained I'm glad I dont.

Now I only use expanda foam like polyfilla, to fill large gaps


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## 1woma (Apr 30, 2011)

thanks viridis, i think i'll give the heat torch a miss, i dont need to burn down my bargain cabinet or my house.

Jax i have only used it for the big gaps to, i hated working with it...... trying to use it upside down and get it in the right spot was way to hard lol.... i'll stick to my styro fruit boxs. do you have any pics of your work Jaxrtfm


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## J-A-X (Apr 30, 2011)

I have an Cabinet that I'm converting at the moment, last coat of varnish going on this weekend, but I have started on the inside, ( yes virides, it THE cabinet LOL) I'm taking lots of pics so once it's done I'll post it here and in the DIY group


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## Tinky (Apr 30, 2011)

Woma,

I have always found fruit boxes hard to work with. Great for flat surfaces, but hard to carve and get depth. Im my experience, sheets that are 1.5" to 3" thick are the best to work with.

Contact your locak Target/Kmart/bigW, (loading dock) and ask them to save some wast foam for you. You will get some interesting shapes and bits that may inspire you. Use liquid nails to join pieces.

There are a few picks on my profile if you want to see some of the stuff that I have made.


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## WAG_S (Apr 30, 2011)

i found that if you paint the expander foam or spray oil based products on it before it sets it melts the foam and leave really small bubbles that look like natural rock. give it a shot


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## 1woma (May 2, 2011)

thanks tinky, i have unlimited access to the fruit boxs so i have done my first wall using them, i'll keep target in mind for next time. I also used some packaging from a tv box to make a cave style ledge, i'll try and post some pics when the kids go to school. I made some mistakes but i hope when its all rendered it will look ok.


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## J-A-X (May 2, 2011)

1woma said:


> ...... I made some mistakes but i hope when its all rendered it will look ok.


 
Thats the beauty of making caves and rocks, there is no 'perfect rock' so unless you tell someone they will never know that you goofed


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## 1woma (May 3, 2011)

ok here is were in up to, its not perfect but for my first attempt i think its ok, i'm getting render/grout? on thursday so this weekend should get me closer to finishing


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## J-A-X (May 3, 2011)

its great when you can see it all coming together and looking like 'something' rather than a heap of foam. the painting is the fun bit. ! !


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