Question re `no nails` & expanding foam

If you use a good grab adhesive and rub the joint it will usually hold, if not pin it. Once set it will be strong enough.

That depends how involved you want to get. If you just buy a can it will do what you say & set in the nozzle, you can buy a gun and cleaner if you want to but the cost, mess , time prolly won't be worth it.

Have a look here;

I have two toel rails with ceramic mount . Thet were originally mounted on pb walls with screws, the heads cemented in holes in the ceramic ends. When the en-suite was tiled I smoothed off the back of the ends and fixed them in the tiles with Sticks Like Sh**t. Each supports a bath towel and a hand towel without any problems (and has done for 4 years). The contact area on each of the ends is about 4cm sq.

I dont think that you will have any problems!

Malcolm

Gun/cleaner one of my better DIY investments. Costs certainly (about £15 for the gun?), but no mess, and hasn't clogged yet after about 10 tins of foam. I use a plastic scourer and maybe a squirt of cleaner/solvent before each use, and cleaner between tins.

Foam quickly sets solid and that's it, your can's finished. DON'T decide you can make a little hole & use the foam that comes out. Well, do, but have someone video the whole thing.

Expanding foam will of course break anything & everything. It expands after it has set solid, with huge force. It's an awful product best left for when all other options are unworkable.

NT

On 26 Nov 2015, snipped-for-privacy@gmail.com grunted:

As you aay you haven't used the stuff before, I'm concerned about the description of 'dents' that you want to use it for - do you really mean 'dents'? If so, I very much doubt that foam is the appropriate way forward

Kind of agree; especially about the last sentence... it does have its uses but am not convinced it's the right method for the OP.

Dents. Fill in with plaster & let set. Gaps As above Pus maybe a bit of scrim (woven tape) to prevent cracking.

Then plaster skim as normal.

Or use polyfilla, takes longer to go off = more time to mess about with it.

Foam is totally unsuitable unless gaps are really big. If so, fill gap, let set & trim off with bread knife.

I only tried "can foam" once, and as others have said you pretty well need to use it all or lose the remnants, "gun foam" is OK to stop/start over a few weeks, if you leave a can in it for a few months the gun will likely require stripping down and cleaning out.

You can get low expansion foam, e.g. as an alternative to dot'n'dab fixing of plasterboards, I've used it for drylining a porch that had been painted brick - it isn't instant grab so needs propping or leaning on for a while after the board is offered up.

Not sure if the O/P wanted to use the foam as a filler, or to glue patches of plasterboard in place? The high expansion foam can be useful to fill the bulk of a big void before smoothing over with something else, but I wouldn't go out of my way to use foam ...

To answer some questi The`dents` are a couple of holes in the plasterboard from ripping off tiles, the state of the plasterboard is generally ok, I planned to fill the holes with foam then a thin skim with one coat over the complete partition, I will be retiling it. Partition is 5 x 4 feet. `Gaps`: where I have taken off a couple of sheets of badly damaged plasterboard there is a gap about 3 cms wide between the floorboards and the wooden wall frame (studs) This gap leads to the underfloor ground area. The reason I earlier asked about using the foam over a period is that I will proably discover more `damage` as I progress.

Foam would be an awful choice. The topcoat would break up due to inadequate support anyway. Use filler - if you need to really skimp, fill the filler with bits of PB, stones, etc.

Again foam is the last possible resort. Use wood.

NT

OK points noted.

I agree with that, from the sound of the OP's description.

Unless the holes go right through the plasterboard and are big, enough when I'd give it a quick squirt

If this is just to fill teh gap, stop are movement etc, then I'd probably use foam, rather than faf about with bits of wood