Supposedly, apparently, pros use metal pistol attachments for nozzle-less expansion foam canisters. Does anyone know why?
AFAICT, the pistols are a bit costly. The pistols themselves can get clogged and add a maintenance burden. You need to then buy a can of special cleaning solution (is it acetone?), to spray through the pistol after every use.
I have always used the foam for DiYers: a canister with a nozzle and long plastic straw. The straws are trivial to work with: you twist a screw into the end of the straw when done to seal it off. The stuff in the straw still dries out but it’s easily cleared by plunging it. A coat hanger can push it all out in one piece.
Twice those things have fucked me. I buy a huge can of the stuff and use it for one small squirt somewhere. Then the stuff cures inside the can near the outlet, thus sealing it off. There is no recourse because label even tells you that you’re going to get fucked. The label says “one time use”. Indeed, they expect you to blow the whole load in a single giant ejaculation. WTF? Now I have cans of barely used expansion foam with lots of liquid trapped inside the can. I don’t recall if I tried the spraying it upside down trick to clear the nozzle.
So I have to wonder, is the pro stuff any different? Wouldn’t the pro canister outlet self-seal just the same? A hardware store near me is going out of business and I have a chance to buy a pistol at ½ price. Not sure it’s worth it.
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Used both a lot in my renovation. I’d never go without pistol again.
A) it helps control the amount way better B) you can just shut it off and use the rest later on without bothering with sealing it airtight. C) better handling and weight distribution
The pistol addresses your main concern. The can stays on the pistol and is good to go even for weeks.
And the cleaning part doesn’t matter to be honest. I spent a few bugs on the cleaning spray (basically alcohol/acetone solution as you’ve guessed) which can be easily sprayed. After use I spray a bit into the opening of the pistol.
I like to have it available in case I fuck something up or want to protect a surface, would even spend the money without the pistol.
The pistol costed like 15 Euro and saved me several hours by now.
The cleaning spray I would get even without a pistol just because it’s so handy to quickly dissolve foam.
Good points. I just wanted to add to make sure you turn the flow control knob tightly off every time you are done with it. And never leave an empty can on it, change it quickly. I leave a can on mine permanently so its always ready to go. Can use a tiny amount then then close the flow control knob off. I have let mine sit for over 6 months with no issues. I only clean it rarely when I don’t have a fresh can to put on. I have only gone though two foam pistols/guns in 15 years. I would never use the normal cans again. Way to much waste.
Good additions, thank you!
I’m a bit paranoid and spray a bit of acetone on the tip after use but in theory it should be unnecessary.
How does the nozzle not clog after you are done? Are you saying with the handle version you can screw on a can and use it every now and then?
If so that would be huge for me. As a home user I need spray foam once every few years and hate needing to buy a new can and throw out the half used old because it’s clogged.
Are you saying with the handle version you can screw on a can and use it every now and then?
The foam gun seals at the very tip of the nozzle. Once you attach a foam bottle, the entire gun effectively becomes part of the pressurized bottle, and you can store it like that for months - but probably not years. However, if you set a reminder a couple times a year and spray some of the foam out from the gun to “freshen it up,” then it should stay in operating condition for the next time you need it.
That said, if you only need it once every few years, there’s probably no reason not to just buy a single-use bottle even if you don’t use all of it.
I prevent it but spraying a bit of the acetone into the tip after use.
And the screw is on the Pistole (the wheel at the rear end, looks a bit different on mine than on OPs photo but same principle).
In theory the acetone is not even needed because it has a ball bearing tip that is airtight and that prevents the drying but I never tested the concept.
If you’re going to use it all at once, then just buying the bottle with the straw is fine.
However, if you’re going to need it every now and then over a longer period, or you want better flow control and a narrower nozzle, then the pro gun is the way to go. You can (and should) just leave the bottle attached to the gun permanently. It’ll stay good for a few months like that.
If you need to store it longer, just periodically spray some out, then close it up again and it’ll keep fine. In my experience the cleaning solution doesn’t fully clean the gun and it will eventually clog. That said, I just heard one guy say he hasn’t cleaned his gun in 3 years - he just swaps in fresh bottles when they run out and it’s been fine.
The important part is to tighten the flow control knob after use, because simply releasing the trigger won’t fully seal it for long-term storage.
The metal pro guns flow a lot more and have way better control over the flow. Awesome to use on big jobs. They do require cleaning. It will still cure in the nozzle.
With single use cans sometimes the spraying them upside down thing works but if you’re trying to get another use do that, take the straw off, and stick a piece of wire into the little tip on the can. The foam expands as it cures. You just need a little hole for it to get through and the pressure can push some blockage out.