Plaster – Corner Bead Cracking?

stuart45

It's when you need one of these that you know it's time for a new trowel.
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paperclap

A concrete planer?! My God. Didn't even know that was a thing!

FreeBear

paperclap said:

This might sound a bit crazy… but would an electric sander be too aggressive for sanding plaster? Is there a risk of loosing the plaster?

Would be ideal if I could use one, merely for the dust extraction.

Different grits will dictate how aggressive the sanding is. 60 grit might be a bit too coarse, whilst 120 grit barely does anything.

And yes, you want dust extraction. Lots of it. Don't forget the dust mask & goggles either.

paperclap

Good thing I've got 80 grit then! 

Yep, 100%. I practically live in my Trend Stealth P3R mask.

travis-powers

paperclap said:

Good thing I've got 80 grit then! 

Yep, 100%. I practically live in my Trend Stealth P3R mask.

I got one of them free with a worktop jig, it’s absolutely brilliant, the only mask I’ve used that doesn’t steam up my glasses!

Grenage

I normally use an orbital sander attached to a wet and dry vac when decorating.  Much quicker!

paperclap

Well, all sanded just fine. Now about to mist coat. But before I do, y’all got me thinking about the potential for these “galvanised” corner beads to rust. When plastering, I did very lightly use the edge of my trowel to clean up that bead, and I’ve also sanded bits off.

Zinsser BIN was recommended here, but shellac isn’t waterproof. Though, does say on the back of the tin is could be used to cover rust stains? Got a tin of this beaut.

Or, is it worth using an oil-based paint? I’ve got an opened tin of satinwood (self undercoating) handy. Probably not ideal, but hey, it’s what I’ve got.

EDIT: Didn’t bother in the end! Just whacked the mist coat right on. If it rusts, I’ll deal with it then!

Grenage

For future ref, any oil paint would be fine.  Just needs a light sanding before top coat.

ThisIsWeird

paperclap said:

Well, all sanded just fine. Now about to mist coat. But before I do, y’all got me thinking about the potential for these “galvanised” corner beads to rust. When plastering, I did very lightly use the edge of my trowel to clean up that bead, and I’ve also sanded bits off.

Zinsser BIN was recommended here, but shellac isn’t waterproof. Though, does say on the back of the tin is could be used to cover rust stains? Got a tin of this beaut.

Or, is it worth using an oil-based paint? I’ve got an opened tin of satinwood (self undercoating) handy. Probably not ideal, but hey, it’s what I’ve got.

EDIT: Didn’t bother in the end! Just whacked the mist coat right on. If it rusts, I’ll deal with it then!

Yes, I always try it and see, and if it doesn't rust-stain, then all is good. If it does, then you need a sealer of some sort - oil based paint should do, but apply thinly and feather, so as not to show through as a flash.

paperclap

Thanks guys! I’d be quite shocked if it did… but we’ll see!