Best heavy duty filler or render in deeply damaged plaster?

[fairplay]

I have been ripping out the old basic sixties skirting in our spare bedroom. Of course it was fixed with an excess of those hefty great cut clasp nails. I have found the best way to remove it is to cut either side of them with my multitool saw and then remove the skirting then the nails. But it absolutely pulls out loads of the old plaster, leaving quite big holes in places. The new skirting is taller so will cover it but what is the best way to fill the damage sufficiently so that I can dab and dot the adhesive for the new MDF skirting?

 

[blup]

Have found this very good for deeper holes, ready mixed and lasts a long time in the tub:

Ronseal Big Hole Ready Mixed Wall Filler Grey 1.2Ltr | Multi Purpose Fillers | Screwfix.com

Blup

 

[JohnD]

You don't have to pull out cut nails, you can break them off.

 

[lostinthelight]

If the skirting is sticking to the wall, run the MT down the back with an old blade to free it.I don't throw blunt blades away until there's only a stump left.
If its pulling the nails thats doing the damage split along the grain of the piece left after you've cut down either side and disk the nail off flush

 

[fairplay]

If the skirting is sticking to the wall, run the MT down the back with an old blade to free it.I don't throw blunt blades away until there's only a stump left.
If its pulling the nails thats doing the damage split along the grain of the piece left after you've cut down either side and disk the nail off flush

Thanks, that sounds like the best idea. "Breaking them off " wouldn't work because the plaster is too crumbly.
Also thanks blup for the heads up on the filler.

 

[blup]

Need to build up in layers if holes are deep, otherwise may not fully dry out.

Blup

 

[Matt108]

Have found this very good for deeper holes, ready mixed and lasts a long time in the tub:

Used Big Hole myself. excellent product.

Tiny tip: when long stored in tub, but a little dry then add some water to bring it back to life.

 

[blup]

Used Big Hole myself. excellent product.

Tiny tip: when long stored in tub, but a little dry then add some water to bring it back to life.

Yes, done that, brings it back to a workable state.

Blup

 

[perky416]

I tend to lean towards plasterboard adhesive if i need to fill deep or large holes. It doesnt shrink or crack and dries rock solid. Leave it below the finished level though and go over with normal filler or plaster as its a pain to sand.