-
Amazing. Super helpful as always.
I think I'll go with the Fibarex first as it's a delivery thing for me, then if needed I can swing by Screwfix. I guess I'll grab the 3 piece set and a big float, but leave the external corner one.
Think I'll also grab a 4½ grinder as I've been holding on buying one until the next DIY job comes up. I reckon it'll be faster/easier using one with the brilo pad discs than going at it with a wire brush.
hugo7-
Angle grinder is one of my least used tools. I guess it could be useful in this case but you'll need to be very careful not to leave the surface covered in ridges.
I've been using an IR stripper with some success on cement cills but mostly I chip paint off with a hammer and sharp chisel. I guess it's a technique that you get better at after you've done a few hours though!
-
A stonemason used a sanding flap disc on our sandstone cills. It avoids the problem of ridges that Airhead mentions,
Although on concrete. Ick.
To repair, they built a form, and used chicken wire reinforcement. I'd be tempted to do similar with a concrete block, and maybe use reinforcement fibres rather than faffing with wire.
Airhead
NotThamesWater
There's Murex and Fibarex that are both common for exterior repairs. Fibarex is reinforced with fibres to provide some resistance to cracking, Murex has a high marble content and can be used on corners unsupported without slumping. Ideally you'd have both and pick which one suits the area best. The decorators supplier I use is an independant and they will sell the individual 1kg bags out of the 5 kilo big bags so it's easier to get what you want without having loads left over.
I wouldn't bother with an exterior corner trowel, you can use 2 trowels to get the same result or use a ply former. You can sort a lot out by sanding on exterior corners anyway.
Touprelith is the grey cement filler, I have used it in the past but Murex took over for some reason.