Plaster Bonder or Water over old Brown Coat?

[totallyfake1]

Quick question for the plastering gurus:

I've got some walls which I went at last weekend, pulling down anything that was loose and crumbly. In some spots, this took me down to the lath, but in large portions, the brown coat is still quite solid (and well-affixed to the lath), and only the skimcoat came free. I'll be filling in the big holes with structolite and then skim coating. But I'm not sure what to do about the spots where there is still solid browncoat.

I've seen some instructions to wet the lighty wet the old brown coat and then skimcoat over it, but I'm wondering if putting plaster bonder (PVA compound) over the browncoat would be better still. After all, the last skimcoat didn't "take" very well.

Any thoughts?

[Ken]

Well, I'm no expert, but I'll give you my opinion.

In that situation, I would make sure that the remaining brown coat surface is sound, no more loose bits to come off, and then put on a coat of bonding agent, then do the skim coat. You may be able to get away with just wetting the brown coat, but I think in the long run the bonding agent will be better.

BTW, when I break out loose pieces of plaster all the way down to the lath, I paint bonding agent onto the lath before doing the new brown coat. I figure that way if I don't get the entire brown coat keyed well, its a little extra insurance to help keep the brown coat bonded to the lath. I'm just an amateur, so there is a distinct possibility that I might not always get the brown coat keyed well.

Ken