Using Expanding Foam!!

[albaPhenom]

I've come to the realisation that I am absolutely hopeless at using cannister foam and also to a lesser degree, silicone sealants.

I get it f***ing EVERYWHERE and end up cursing and swearing at everything and everybody, most of it I admit is my own fault because I barge in clumsily, not taking enough precautions or making sure I have everything I need to start with e.g. gloves, clothes, scrapers. etc

So for anyone who uses cannister foam regularly or is a bit of a dab hand at it, what are tips and tricks to make sure you apply it as cleanly and neatly as possible.

 

[freddiemercurystwin]

Go in cautiously, take adequate precautions, making sure you have everything you need to start with e.g. gloves, clothes, scrapers. etc

 

[albaPhenom]

Go in cautiously, take adequate precautions, making sure you have everything you need to start with e.g. gloves, clothes, scrapers. etc

I never thought of that one, good tips all round.

 

[JP_]

lol. It is a nightmare. Very handy though. Have a good sharp knife for trimming the next day.

 

[Deleted member 174758]

Apart from the obvious about planning and preparation, don't just pull the trigger hard and hope! Multiple short, gentle tugs of the trigger and only ever partially pulling the trigger - resulting in a controlled flow - is the only way to approach it. Sorry to say it, but you really do need to learn both control and finesse!

 

[JohnD]

A technique I used around window frames, worked very well:

mask off the surrounding frame, wall, floor etc with clingfilm, newspaper and masking tape

Have some disposable rags, and at least a hundred nitrile gloves so you can throw them away the moment they get foam on tham. Cover hair, skin, clothes, shoes, and especially eyeballs. Have a water sprayer handy so you can spray any spillage so it forms a non-sticky crust.Do not step on sticky foam

Prepare a batten of suitable size to block off the gap. Drill 10mm holes in it so you can inject through the holes into the gap

wrap the batten in clingfilm

clean and spay the gap lightly with water.

attach the batten to the frame or wall so it is over the gap

inject, slowly, through the holes. Start with the bottom ones. When the foam comes out of the hole above, the lowest gap is full.

The next day, pry off the batten and clean off the clingfilm. The batten will have prevented the foam from bulging out of the gap, and it will have set, pretty well flat, where it was against the batten, so you should have minimal cutting and sanding to do.

Protect it from sunlight with paint, silicone or a trim

Most foam expands quite a lot, and can push a weak, flat material out. So apply it in small amounts, and wait for it to stop expanding before adding more. Water makes it expand quickly, and form a crust. In my case there was a cavity around the windowframes for it to expand into.

With practice, I can now do doorframes with minimal preparation, using a gun and nozzle and fine control, because I have learned pretty well how much it will expand. Practice somewhere that does not show, e.g. filling gaps around a ceiling from above.

I use an adjustable Fischer gun.

 

[Deleted member 174758]

We also use low expansion foam on door casings and windows these days, John. Saves a lot of trimming back later on

 

[BlueLoo]

It's like having sex.

Everything needs to well prepared and clean. Start slowly, make sure to keep at it and don't stop until you are finished. Clean up can be messy but needs to be done immediately else it gets difficult.

 

[albaPhenom]

It's like having sex.

Everything needs to well prepared and clean. Start slowly, make sure to keep at it and don't stop until you are finished. Clean up can be messy but needs to be done immediately else it gets difficult.

 

[Deleted member 174758]

Clean up can be messy but needs to be done immediately else it gets difficult.

I don't know how you have sex, however...

If you are working carefully and don't spray too much (back on topic, now - clue: apply foam sparingly and if needs be top up later, too little is better than too much) there should be very little squeeze out. In my experience, cleaning up immediately is a sure fire way of spreading it all over the place - better to wait until it has set because then it is so much easier to deal with

OP: if you really can't get to grips with using standard cans, consider spending about £20 on a foam gun and switch to using gun grade foam (same foam, different can although a few firms have cans that work both ways). Foam guns are very controllable with the ability to turn the flow up and down. The downside (apart from the cost of the gun) is that you need to keep the gun scrupulously clean. So, if you use up the foam cannister on it and haven't got a replacement to hand for immediate installation you do need to clean out the gun straight away with gun cleaner (about £7 to £8 a can) and ideally strip it down and clean off the components as well. Don't do that and it'll probably be junk next time you want to use it

 

[foxhole]

Keep a Can of lighter fuel handy, will destroy uncurred foam instantly and dropped into nozzle after use will clean quickly.

 

[Deleted member 174758]

Keep a Can of lighter fuel handy, will destroy uncurred foam instantly and dropped into nozzle after use will clean quickly.

Can attack the seals inside the gun, though (if using a gun). The proper cleaner is acetone and comes in a spray can which can be attached to the gun to thoroughly clean the insides of the gun

 

[mrrusty]

cannister foam

You ARE using an application gun and not just the aerosol type foam? If not - go buy a gun and use foam with the screw-on canisters. If you are already using a gun and still getting it everywhere, go buy a better gun with better control.

 

[johnny2007]

My advice: spray very little.
You've already sprayed too much.
That thing expands like mad, so when you think you haven't sprayed enough of it, you've already sprayed too much.

 

[foxhole]

Can attack the seals inside the gun, though (if using a gun). The proper cleaner is acetone and comes in a spray can which can be attached to the gun to thoroughly clean the insides of the gun

No seen any seals on my guns, all internals are brass.