Joint compound. Silverset or Easy Sand.

Truly not spackle.

Apply with putty knife. Sand smooth. Vacuum and wipe up dust. Prime and paint.

Will most likely take two applications. One to mostly fill. And a second to make flush with the surrounding wall.

Hi, This is just an idea I have seen it done on siding. Get some corks, put them in the holes, trim maybe drive in just a little and fill. I would use mud. then paint.

Woodbutcher

So, nobody likes "patching plaster?" Also, no tape? The cork thing sounds like a good idea. I had thought about partially stuffing the holes with something first, just to give the mud some backing. Any chance that expansion would be a problem? Just hope I can find drywall compound in something other than 5-gallon quantities. Thanks.

If its plaster you do not want to use drywall compound if you want it to stay consistent. Use plaster of paris, and add something for backing if you can get it to stay in place in the small holes. You may be able to attach short pieces of wood or other backing to the existing lathe by just stuffing it into the holes after applying a liberal amount of glue. You just need something in there to hold the plaster in place while it sets up.

Most powdered plaster mixes are chemically activated and only stay workable for a very short time, but at least you don't have big areas to patch. When you mix the plaster it takes about 4-5 minutes of mixing to get a relatively solid consistency that works well for patching, and then you only have about 10 minutes to work with that batch of plaster before it hardens too much and starts to ball up. Once you get the patch in place it will only take about an hour for it to harden up enough to sand.

Bruce

Tape for what?

The cork thing sounds like a bad idea and extra work. Although it does sound like a good idea for wood siding since the expansion rates would be similiar.

The pre mixed joint compound in the 5 gallon bucket is garbage. Do not use that...

I suggested this product: http://www.homedepot.com/p/BEADEX-Brand-18-lb-Silver-Set-40-Setting-Type-Joint-Compound-385268/202329688

It's less than 10 dollars.

This is Plaster of Paris with some other ingredients to retard set time. Read the label on it.

Or you could just use straight plaster of Paris. Whether your straight PoP or "setting type" joint compound you do not want to mix it for four or five minutes. Especially not PoP. That will drastically reduce your working time. Will add air bubbles, and reduce how well the product tools out.

If you go the plaster of paris route, use as cold of water as possible (maybe even refrigerated) Add water to your container first. Then slowly add the plaster to it so the plaster is just slightly peaking above the water level. Let the plaster slowly hydrate itself for a minute or two. Then slowly incorporate it with what ever you have to mix it with to ensure the product is evenly mixed. Make it thick.

With the size of the holes you are patching, nothing needs to be added as a backer. In fact, you want the plaster to push through the back and droop down to really lock it in place. No matter though, it will stick to the sides of the hole well enough.

Fill holes. Let cure. Sand. Final level coat. Sand again. Prime and paint.

Get a piece of backer rod and cut off some short pieces to fill the holes.Use 20 minute Durabond or Easy Sand for the holes.Overfill slightly.This stuff shrinks very little so if you overfill a slight bit you should have a little to sand flush and be able to get by with on coat.

Guys, guys. I'm talking about a half-dozen holes between 1/2 and 3/4
inch that go all the way through an otherwise very solid 80-year-old
plaster-and-lath wall. I'm not going to replaster an entire house. I'm
just looking for a ready-made product in a small tub that I can use to
fill these holes, with or without the backing rod (which sounds like an
OK idea to me, better than cork). Thanks for all the advice -- and I'm
sorry to trigger such a debate.

Joint compound comes in quart containers most anywhere.