Patching and Plastering - So, I decided to start scraping...

OK, I swear none of the posts in the past few pages have covered this, so bear with me...

Aiming to repaint our kitchen ceiling. Since we moved in, there's been a small water-stained area with some cracking paint (about 6" x 6"). It hasn't gotten bigger or changed in 3 years. Just above, in the attic is an exhaust(?) pipe, which looks like it was patched with silicone some time ago - it's dry as a bone up there now. Ain't no way it's leaked for at least 20 years.

I scraped away at the paint to pull some of it away, planning to use a vinyl spackle, sand, and repaint. Started scraping very lightly with a metal mud knife, moved up to a wide chisel, and now I have what looks like cement(?) beneath about 1/16" of paint and plaster. I had no idea this cement layer was there. Is it really cement?? Anyhoo, I quit scraping, cuz I wanted to check in with my DIY amigos. Now I have a 3" x 3" cement area. And I still have what seems like a "tapping" sound where there might be space between the plaster and concrete on the remaining discolored area.

My main questions are:
1.) should I continue to scrape until all discolored paint/plaster is removed?
2.) will vinyl spackle adhere to the concrete area once I'm done scraping? Or should I use something else?

Thanks a million,

-Woostah

Generally you don't need to remove plaster because it's discolored. As long as it isn't crumbly or loose you can seal it with a solvent based primer.

The 'cement' layer is the plaster brown coat. Don't use spackling to repair. What I usually do is paint that area of the plaster and then use a setting compound to repair the damage. I'm no plaster pro........ but we have one that will chime in later :D

Chimes.

Go ahead and scrape what comes off easily. If you have to sweat to get it off then stop.
I suppose to do it yourself use a setting type joint compound like EasySand to patch it. Try not to build any up on the existing good plaster. In other words keep the new exactly flush with the existing. Just as that joint compound sets you can mist it with a spray bottle and trowel it and get it almost as slick as the existing plaster. As soon as the first coat is hard a second coat can be added if necessary and when it's dry you can sand it. fix any imperfections and sand them and prime and paint.

If I were doing it I would use some plaster finish but it isn't as amateur friendly and is harder to sand. It would be faster to do it this way but if it isn't right it's nearly impossible to sand and scrape off and try again so use the joint compound.

Thanks, Marksr.

I had to scrape off some of the paint since it was flaking - didn't want to paint over that, right?

When I did that, I felt the "middle" coat - between the paint and the plaster brown coat - sort of "bubbling up" - or at least there seemed to be space between it and the brown coat. The brown coat isn't damaged or cracked at all. So my spackle isn't really filling any holes, just replacing that fine layer of paint plus plaster finish(?) - sorry, I don't know my plaster terminology.

So, still best to NOT use vinyl spackle?

-Woostah

Whoa - Tightcoat - I knew I should have waited for your reply...

Thanks a million. This makes it clearer - right, so I'm really just replacing that plaster finish(?) coat - not messing at all with the brown coat.

Tightcoat - best to use joint compound, or is vinyl spackle ok here? Will it adhere to the brown coat?

Thanks again!!

-Woostah

Spackling is formulated for minor repairs [dings,nail holes,etc] and is not intended for larger repairs.

Marksr - thanks - got it - spackle for the small stuff. Which is what I've had up until this water spot.

Now I've gone and done it. I kept peeling away the plaster top coat - not using a lot of pressure - just trying to get rid of the stuff that would flake off easily.

As I did that, I found the ugly center of the spot - the brown coat has a hole about 1/4" deep and about 2" in diameter. It seems a bit crumbly - what the heck do I do now?? :mad:

I should be able to DIY-it, right? But what kind of repair agent? I'll read some other posts, too, and see what I can come up with, but drop me a reply if you can.

Thanks!

-Woostah

No larger than this hole is use the EasySand. Unless you can find a quart of StructoLite.

Tightcoat and Marksr -

Got it EasySand or StructoLite. Now, Marksr suggests painting the brown coat if it's dusty or crumbly? With what? Regular ol' paint? Primer?

Or, is it not necessary - will the EasySand or StructoLite adhere to the crumbly brown coat?

-Woostah

If everything is sound it will bond just fine. if it's crumbly some paint won't hurt. it might give you a little more working time too.
Use a plaster bonding agent. Plaster-Weld or something like it. I suppose some latex or acrylic paint or Elmer's glue would work too. Grind the first coat of mud into the brown coat pretty tight then double back and fill it out a little more. Keep adding coats as necessary to get flush.
Let us know how it goes.

How big of a section is the water damage? You may find that more will want to come off and your hole will get bigger. It may be easier to cut out the bad section, replace with drywall, and tape and mud it. Sometimes what seems like more work can actually be easier.

Brewcity - I take your point. BUT, I think I'm going with the patch job. The 1/4" hole in the brown coat is about 2" diameter. Outside of that the brown coat is smooth and solid as can be. Wish me luck..:o

Tightcoat - OK, got the skinny on the bonding agent, etc. BUT, if I do decide to throw a layer of paint on it first, do I let that dry, or what??

I'll try to get some pics up for you guys.

Thanks!

-Woostah

If you go to the trouble of either a bonding agent or paint let it dry. That dry plaster will soak the moisture out of it fast. Probably be dry in an hour or two.

Do you live in Kansas or have family roots there?

Worcester maybe?

Alright, then. I'm headed to the store. We'll see what I walk out of there with. I gotta get this behind me and get sanding and painting - much to do in this kitchen!

Tightcoat - actually, I live in Worcester, MA, outside of Boston. That's the accent/pronunciation out here - Woostah - no "r's" in Boston!!

-Woostah

Yeah, my dwiveway just got paaaaaved so I have to pak my ca in the yad. I love the accent der hey (I'm from the midwest)! No offense taken to your decision. I'm an electrician by trade anyways, so I'm no expert. I've done quite a bit of mudding though and chipped a lot of paint. From my experience, where there's a little chipping, there's a lot of scraping. I'm glad that you're more fortunate. Hope it all works out nicely for you! let us know how it went.