Expanding foam for mould, solid enough ?

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Expanding foam for mould, solid enough ?

http://www.talkcomposites.com/Topic19338.aspx

By TURK - 9/26/2015 10:45:12 AM

Hi all,

Anybody used the expanding foam you can buy from the diy stores, in aerosol form.

I'd like to know what the difference is between that, and the 2 part stuff available. I understand that the 2 part stuff may be 'closed cell', probably making it harder. But can I get away with using the normal aerosol stuff usually used for insulation purposes ?

I'd like to spray it into a form ( female mould ) about the size of a shoe box, then demould the expanded spray foam, and then brush on layers of Pattern-Coat Primer to make it harder to use as a main male mould.

TURK

By Zedok - 10/12/2015 12:54:56 PM

Hanaldo,

Sorry for the late reply. Just wanted to say that I have used expanding foam to make a canoe plug. Initially, I had made the error of building a female mould without a plug... I know, just ridiculous. Anyhow, I used three cases of 750ml containers to fill-in the would be female mould. It worked perfectly except that if you spray too much in one go, the interior part of the foam mass will not expand. Otherwise, by spraying layers of maximum 10cm, waiting for expansion and dry, you can add as many layers as you want. Sanding is a breeze and you can then cover the plug with body filler before finishing with getcoat.