Sandable topcoat/skimcoat over plaster?

Hello plaster gurus,
I had some BIG holes in my 100+ year-old plaster which I decided to fix myself. I have never plastered before, but I thought I'd give it a try. Took me an age to find suppliers for the plaster, etc, but I got it together and jumped in.
I have put in a scratch and brown coat using Structolite and I have filled in the last 1/16 or so with Diamond veneer plaster. Now I'd like to do a final skimcoat over the whole wall - that is, over my patches, and over the paint (and in some cases wallpaper backing paper) from the unpatched sections.
My plastering technique has improved quite a bit as I've done all this, but not enough to give me the kind of smooth surface that I want (or my wife demands, I should say!). Therefore, I think a final skim-coating with Diamond veneer would be a bad idea. If I had a few more rooms to practice on (in someone else's house?), I think I'd be ok, but that isn't an option.
So... my question to the plaster gurus. Which product which you all would recommend for this final skimcoating? I was thinking maybe USG Topping Compound? My number one concern is a forgiving mixture which allows me to sand down my mistakes. Pre-mixed would be a boon too.
Thanks so much...
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Uh oh. That will make you very, very sad, if my experience in a previous home is any indication.
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I agree that it isn't ideal. However, most or all of those spots will be covered by new wainscoting. Also, I note that what remains is a pretty porous paper backing material which seems to have more in common with sheetrock facing than with wallpaper. I am less concerned about adhesion there than I am about the topping over plaster. If THAT stuff starts peeling away/cracking, the wainscoting won't help me!
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Doug Kanter wrote:

Yeh, me too :o) I know almost nothing about plaster, except that it is fun to make kids' handprints in :o) I would not put it over wallpaper - the water in plaster is likely to loosen the wallpaper, leaving a nice mess to contend with.
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What finish are you seeking?
Finishing the walls with clay has become kinda the latest "thing" http://www.americanclay.com Venetian finish is quite similar.
It is unusual to go for no texture which is what it sounds like you are attempting. I assume some of your walls have been painted and I would be concerned about the adhesion of some plasters over a painted surface. I would experiment on a small area to test. You can "pant" everything with Larsen's to improve the adhesion . Drywall compound is better about sticking to multiple old finishes in my opinion. It does not lend itself to hard toweling to a smooth finish like plaster does. You can lightly scrape and remove as much texture as possible and skim coat, dry, sand, re-skim, dry, sand, repeat until smooth. Here is a short article: http://www.extremehowto.com/xh/article.asp?article_id `264
A light texture adds character, ambiance, and light diffusion to a wall. That sounded kind of neat! <grin> In reality, texture helps disguise irregularities in the wall. Plaster texture can be hard troweled to slick, float textured with a cedar shingle float, soft green sponge float, cork float, dash coat, Spanish, Venetian, etc. Each will give a slight variation to the finish as will the type and size of sand (if any) in the finish coat. These samples are mostly exterior, but interiors can be dealt with much the same: http://www.plasterconnect.com/residential/plaster_textures.html#lightlace Here are several textures, but they emphasize the paint job: http://www.hesterdecorating.com/showroom.htm
______________________________ Keep the whole world singing . . . . DanG (remove the sevens) snipped-for-privacy@7cox.net

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DanG wrote:

Venetian plaster isn't a finish, it's a different product than your standard lime plaster.
R
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