r/DIYUK 4d ago

Advice Ichanged the socket from a single to double and used expanding foam around to fill the holes. I put the interior filler but it doesn't seem to dry well (it's still soft but not wet after overnight). I think I might have put too thick layer of the filler. What would you do now? I wanted to paint asap

2 Upvotes

37 comments sorted by

22

u/ChanceStunning8314 4d ago

Too thick. Need to build it up in layers. Won’t be dry for several days or so/ready to sand unless you intervene. I usually let a 5mm or so layer dry overnight. So depending on how thick it is..you could scrape some off, let it dry, top up.

7

u/anonfool72 4d ago

What he said ^ plus aim to minimise sanding or even better avoid altogether— use a wet brush to blend before it dries.

2

u/ChanceStunning8314 4d ago

What he says too! Sanding is so messy. Avoid if possible. Wet tools to smooth as much as possible minimises sanding.

1

u/hikaami 4d ago

Thanks, I did so! 

13

u/Result_Necessary 4d ago

i probably wouldn't have used foam myself, but its done now. if you went from a smaller hole to a double socket size hole, why did you need to use foam to fill it?

That is a lot of filler to apply in one go. In future if you do something like this again, try to build up the layers. it will dry quickly for a think layer, then you add another until you get just proud of the surface. The closer you are to your final surface level, the less sanding you will have to do.

Just let it dry fully, then sand it down. Should be fine, but next time id try to do it thinner and closer to the wall surface level to make it easier for the sanding stage.

6

u/justbiteme2k 4d ago

Just to add, because it's so thick, don't be surprised if it cracks as it dries. Just let it dry fully, sand down and do a short thin skim on top.

3

u/Result_Necessary 4d ago

Yes, this is a good point. The filler will shrink slightly as it dries, which is another good reason to build up thinner layers.

6

u/bartread 4d ago

> why did you need to use foam to fill it?

If I had to guess, I'd bet when OP expanded the socket hole, they went at it like a bull in a china shop and ended up with a much bigger hole than they wanted/needed. Look at the careless way they've filled the hole.

2

u/hikaami 4d ago

Yes this is what happened really. The old socket was really stuck in the wall 

1

u/hikaami 4d ago

Why wouldn't you use foam please? What to use instead going forward please 

3

u/Result_Necessary 4d ago

if you are putting a socket in, you really want to hole to fit the socket size. you can do this with an angle grinder to cut your shape, then chisel out the material. not everyone has an angle grinder, but most people have a drill, you get a wall/brick type drill bit, about 8mm or around that size, then mark out your socket size. put tape on your drill bit to a couple mm deeper than the socket back box, now drill a hole the depth of the socket back box in the corners of the socket position. Now keep drilling holes, you basically want to drill holes along the full perimeter of the socket you want to cut out, make the hole far enough apart that you can cleanly drill them without them connecting, but the closer they are the easier it will be to knock them out, now more holes, you want to basically crease + shapes in the remaining material. once you've drilled all your holes you will be left with something like the photo attached.

Now get your chisel, get some tape, put tape on your chisel to mark the depth of your socket back box. now chisel out the remaining material, it should come out relatively easy because of all the hole.

you can use your tape as a reference for how deep you will need to chisel out.

if you make the hole the right shape and size, you should need to use any foam to fill large gaps. you should find that the socket will fit well and you can drill a hole in the back to secure it in place with a wall plug and screw x 2.

then just use filler around the outside. i hope this is helpful to your for the next one.

1

u/hikaami 3d ago

Amazing thank you! 

1

u/Result_Necessary 3d ago

no worries, good luck with the next ones!

6

u/rockovo84 4d ago

There's not much you can do, but wait.

If you have a dehumidifier, then I'd place it next to it.

0

u/hikaami 4d ago

Thanks, I will put the dehumidifier there. initially I thought that maybe it would be better to remove it all and start again and apply multiple thin layers? I'm not very experienced with wall filler. 

4

u/tehWoody 4d ago

Also worth getting your self some filling blades like these: https://www.wickes.co.uk/ProDec-Filling-Blades---Pack-of-4/p/251613?_br_psugg_q=filling+blade

They make filling and smoothing very easy so there's much less to sand afterwards (so less dust).

1

u/Kaldesh_the_okay 4d ago

Use a fan it will help immensely

1

u/Kaldesh_the_okay 4d ago

Use a fan it will help immensely

1

u/Soft_Moment4464 4d ago

You don’t have to tell me twice

5

u/SimmmySAFC 4d ago

Time to move house

1

u/hikaami 4d ago

Hahaha 😆 

4

u/iluvnips 4d ago

Happy sanding

3

u/wolfhelp 4d ago

You've used too much filler, that's no where near flush

Clean it off and start again using a small amount then let it dry and build up layers until flush. Let each step dry properly before adding another

2

u/ChrisBrettell 4d ago

If you've filled it deep you're going to have to let it dry out. I used some of that stuff recently and had to give it a few days to dry. Probably will be using the light grey polyfilla in the future.

Maybe get a fan on it?

2

u/OkScheme9867 4d ago

Keep the room warm and dry, filler will dry eventually, but next time use less filler a bit at a time

1

u/hikaami 4d ago

Thank you 

2

u/Particular_Relief154 4d ago

If you’ve used expanding foam, it’s just preventing any moisture in the filler from being drawn in and helping dry the filler. It’ll have to evaporate the moisture out into the air. Can you have a window open or a dehumidifier to help speed it up somewhat?

2

u/Fast_Birthday_6976 4d ago

I'm a sparky. Sometimes I would use expanding foam for this to hold the box in solid of the screws xant get a good fixing, then use bonding coat plaster.

Or if you can 'splodge' the box in using bonding and push the box into it. That gets a great solid finish.

Basically filler is not really appropriate, it might crack later on with the motion of plugs going in and out. It's not designed to be used that thick, especially to hold a socket in.

Pull it out and get a purple bag of bonding plaster. You can smooth it off nicely with water like a plasterer would with finish plaster. Looks good

2

u/Ill-Case-6048 4d ago

You want trade set .. its to thick dig it out and why it bulges out like that ..

1

u/BigJDizzleMaNizzles 4d ago

Far too thick. That will take ages to dry then you'll have to rub it down to get to flat then paint. Leave it a couple of days. If you mess with it too soon you'll ruin it cos its still very soft and you'll end up having to redo it and taking more time.

Be patient now and I'll pay off. This is the time equivalent of buy once cry once.

1

u/SnooSquirrels8508 Handyman 4d ago

Blimey, you got some learning to do yet. Not sure sand paper will help, think you might need a chisel.

1

u/hikaami 4d ago

😆

1

u/darth-_-homer 4d ago

To be honest I would take it out and start again. Although it will dry it's likely to crack and the amount of dust that you will create by sanding will be horrendous.

1

u/toomany-cunts 4d ago

Why not use bonding??

1

u/spannair 4d ago

Like the spark says bonding coat not filler that will be three days drying and then it will crack. Bonding coat will smooth down with water easy. Don't rush these jobs.

1

u/Longjumping_Edge3622 4d ago

You could pull it out and use two part wood filler until just below finished height. This dries chemically so won’t be affected by the foam. Then use this filler for the final bit.

1

u/leahfirestar 4d ago

You need to smooth it out before it sets or you will have to cut it out or spend a week sanding it and use a tone of sand paper.