expanding foam extension tube - how long can you go?

[garyo]

Does anyone have experience of using an extension hose on an expanding foam gun? I have a 'gun-grade' set up, and need the equivalent of a 1.2 metre extension pipe on it.

If I did it with an 8mm inside diameter plastic pipe then my guess is it'd work for the first couple of minutes, but then does it gradually gum up and write itself off, or does it remain serviceable for an hour or two before you have to bin it and start again?

Thanks

 

[John D v2.0]

I'd have thought it'd be fine, it doesn't go off that quickly until it comes in contract with the atmosphere anyway. If you have the acetone spray you can clean it out straight after and use next time.

 

[garyo]

That's reassuring. I'll give it a go then. I have the acetone canister so can do as you suggest.

 

[catlad]

Get a new nozzel off one of your mastic tubes and use it
as a bung between uses, it should help to keep it longer.

 

[cjard]

The longer you make the tube, the more it destroys the structure of the foam. The foams work best when they emerge from the valve, straight into the world. This is how your gun grade setup works right now. Adding tubes to it produces a more dense foam that is harder to work and expands far less. You'll also burn through cans much quicker

Depending on your need, other forms of foam may be better. Polyurethane foam is available as a two part mix liquid, that you stir, wait 30 seconds then pour (as it starts creaming) and also as a two part pressurised gas bottle kit. Both these foams are superior to gun foam in nearly every way, though the liquid version is far less controllable and the gas bottle version about 3x more expensive (600 version, other versions may vary)

http://www.cfsnet.co.uk/acatalog/CFS_Catalogue__2_Part_Polyurethane_Foam_Liquid_415.html
https://www.abbuildingproducts.co.uk/diy-expanding-spray-foam-kits-c-5012.php

What do you need to use it on that necessitates a 1.2 m tube?