expanding foam guns

[Adam Funk]

I'm thinking of getting some "non-disposable" expanding foam for various insulation & sealing jobs. I've read the wiki article but I have a few extra questions.

Are the cans & guns standardized & When using a gun, the gun can be left on the can for short periods of disuse but must be taken off and cleaned if left for longer periods. Cans of cleaner designed to fit the guns are available.

Do the foam cans seal themselves well (like gas cylinders) when taken off the gun? Do you leave a can of cleaner on the gun when it's not in use, or just blow cleaner through the gun & then leave it open?

Thanks.

[Tim Watts]

Yes

Also yes if using again in the near future.

or just blow cleaner through the gun & then leave it open?

Only if planning to leave unused for a long time.

One more thing - I advise paying extra for the pink fire rated foam. The ordinary stuff is a tad more flammable than I'm happy with having used both.

[John Rumm]

I can't say I have tried all the brands, but they seem to be interchangeable.

It varies... they tend to seal slightly better than the non "gun" cans, but not always perfectly - they will still lose pressure if you leave them long enough IME

I normally rinse through with the cleaner from a can of cleaner, then leave dry. Unless its going to be more than a couple of weeks, I just leave the foam can on the gun.

[Andy Burns]

Yes.

Err, usually!

If I'm not leaving a can of foam on it, then I tend to leave some cleaner in it instead, it's difficult to say how long is "too long" to leave a part used can of foam on it, days is fine, weeks is fine, months usually causes [me] problems.

[John Rumm]

Looks like that VT320 came to a sticky end!

[RJH]

AFAIK, the 'gun grade' foams are standard.

I've kept the same can of foam on for more than 6 months. I find it a really useful source of sticky expanding stuff on tap. In fact, I wouldn't fancy taking the can off in case the foam set right inside the nozzle. That said, the gun I got from screwfix has started to leak around the trigger/pin. Doesn't impair use, yet.

I squirt through with cleaner each time I change cans - seems worthwhile.

[Adam Funk]

Were you the one who posted some test results here recently?

[Adam Funk]

Thanks (to everyone else too).

[Tim Watts]

Yes...

[Adam Funk]

Thought so. Interesting stuff.

[Tim Watts]

Well, for some definition of "interesting". Personally I was a tad pissed off that at least one brand of foam was insanely flammable after curing, especially as another brand of non fire rated stuff appeared to be a lot less so.