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bill02888
Calcimine

It seems as though the ceilings in my 1940something house were "painted" with calcimine. I'm using slightly soapy warm water (sprayed on and allowed to sit for a while) to reactivate it and a scraper to remove it. Messy work.

The layer of plaster that is revealed after I remove calcimine from a section of the ceiling is very shiny. What should I do to that shiny plaster, if anything, after removing the calcimine but before I put on primer?

- Bill

Re: Calcimine

I would recommend sanding it at the least, but it might be better to talk to local plasterers to see if they can recommend what grit to use, or whether there is an etching compound/primer that can be used, or special plaster primer that will embed into the plaster for a sturdy base for paint.

You can also try a Google search of "+painting +plaster", there seem to be a good number of matches that might help.

Ruth Dean
Re: Calcimine

Hi Bill, I renovate repo'd mobile homes for resale and have to deal with sheetrock that has a shiny finish and after literal hundreds of gallons of Kilz as my primer I discovered Gripper a exclusive Home Depot primer product. It works a lot better and it claims to hold on glass. Another thing I have found is proper cure in time. I allow up to 24 hours between coats of primer and paint. So far I have had no one return to me with a problem with their walls since I change over to the new product. ----Ruth

oldfan
Re: Calcimine

There are 2 methods that I used to recommend when I sold paint for 14 years, the first and easiest was if the surface was good. You first scrub the surface with warm water with TSP added then after it dries prime with an oil based (alkyd) primer becuase of it's superior penetration versus latex and after a 24 hour dry time finish with latex or the paint of your choice. This method does not work well if there is peeling paint or layers of paint on top of the calcimine. If there are layers of paint on top of the calcimine this does not work. I have seen this method last many years or fail fairly quickly.
The other method is removal, using warm water with a strong solution of TSP you use the soak and scrape method and follow with a scrubbing pad dipped in mor water and TSP then wipe it down then use the oil based (alkyd) primer then top coat with whatever pain you desire.
As for the shiny plaster you sand with fine sandpaper or use primer for shiny surfaces, I prefered the XIM 400 series primers, that stuff would bond to ceramic tile or glass.

Re: Calcimine

Calcimine is a water based decoration meant to be renewed periodically. If there is paint on top of the calcimine a wallpaper steamer works great, otherwise TSP or a TSP substitute together with a sanding sponge with a fine grit works best. Remember to wear gloves and other safety apparel to protect yourself.

MDTEP112305
Re: Calcimine

Here's a link to an article from Old House Journal on dealing with calcimine...

http://www.oldhousejournal.net/magazine/2001/apr/Cures_for_Calcimine_Ceilings.lasso

I agree with CHYNA that the shiny layer could be paint. Here's another Old House Journal article on paints. It mentions that enamel paints were popular during the era your home was built...

http://www.oldhousejournal.com/npsbriefs2/brief28.shtml

Hope they help!

ordjen
Re: Calcimine

Oh how I remember the 50's when we would frequently find calsomine that someone had painted over with oil paint. We would naively paint over it with the then new latex paints, not knowing that calsomine was under it. It would look great until a few minutes later, the whole ceiling would start bubbling and peeling. It was very labor intensive to get the remaining paint and calsomine to release by use of more water.
Calsomine itself washes off readily. Indeed, that is one of the reasons it was used, it prevented a build-up of paint over the years.
If I were down to slick, bare plaster, I would NOT sand the slick surface. The alkaline understrate will allow scratches to show through water soluable paints. I would opt for primeing with Gripper. Bin also makes a great primer. It seals in the alkaline plaster and can't be beat for adhesion. I prefer the odor of Bin over the solvents that are in most of the oil based primers. I'd rather have an alcohol high over the headache induced by toluene based quick dry oil primers!

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