Friday, June 25, 2010

The Flip Side

The photos of the new old plaster medallion I showed yesterday were taken with the medallion sitting just 1-foot inside the front door. After carrying it from the car that is about as far as I could get. I’m referring to the antique plaster medallion I bought on Craig’s List yesterday.



It is hard to say how much it really weighs. It is not like a 50 pound sack of potatoes that you can really get your arms around and sling it over your shoulder. It may only weigh 50 or 60 pounds, but it is very hard to hold and move. You can only grab it with your hands and you must keep it away from your body, so getting the excess plaster off was a must. Fortunately, 1-foot inside the front door is already a bit of a disaster zone, so working on it there wasn’t an issue.



This is the back side of it. You can see it is filthy and you can also see the impressions of the lath from the ceiling it once hung from. If you look closely you can also see that there are 4 white sections of plaster near the center that have the same lath impressions as the surrounding lime and sand plaster. The white plaster is Plaster of Paris. This is what the medallion itself is made out of. Seeing this was an “Ah Ha” moment for me.



The picture above is from my front parlor. Ignore the brown dots. They are from circa 1970s ceiling tile adhesive from when they stuck ugly ceiling tiles up. You will notice though, that there are 4 circles of white plaster surrounded by lime and sand plaster. This is where a now missing medallion once was. I always assumed that they put 4 dollops of plaster on the back of the medallion and then stuck it on the ceiling, sticking it to the finished plaster ceiling. I now know this is wrong.

What they did was cut out 4 holes in the finished ceiling to expose the lath. They smeared the entire back of the medallion with plaster and put 4 large dollops of plaster on the back to match up with the holes where they exposed the lath. As the medallion was pressed on to the ceiling it formed it’s own keys on the lath. Also, what you can’t see in this picture is that they scored the surrounding lime and sand plaster to give it a better surface to adhere to. Remember the term “scratch coat of plaster”. They really did scratch the surface of the plaster to give the next layer something better to grab a hold of.



The excess plaster on the back was thick. Not only did the medallion have the extra coat of Plaster of Paris with its 4 dollops, it also had 3/8ths of an inch of lime/sand plaster. This easily doubled the weight of it. It is hard to tell from this picture, but that is the exposed surface of the original medallion, then the new coat of Plaster of Paris, and finally the lime plaster.

I first tried just a hand scraper and it worked alright with the remaining ridges of the keys. It had no effect on the Plaster of Paris, and was slow going on the main body of the lime plaster. I would have been there for weeks with the scrapper, so I went back to my trusty friend the Rotozip with the ¼-inch bur bit. I furrowed grooves in the plaster about and inch apart and then chiseled off the rest.



Yes, I said chiseled! Chiseled with a hammer and with butt cheeks tightly clinched through the whole process. I had the feeling the thing was going to crack in two with every swing of the hammer. In the end it came through in one piece, but it was a nail biter. Most of the white you see is the original surface of the medallion and you’ll notice on the right you see more scratch marks where they exposed fresh surface for better adhesion.

It is still heavy, but the weight is manageable now. I’ve also decided that this will go up sooner rather than later. I think it will be better to stick it to the original plaster in the stairwell now rather than wait until after I skim coat. It will make skim coating the ceiling a little more difficult, but there is no sense in having the 1/16th of an inch skim coat sit between the medallion and the original plaster that is structurally sound. Of course, I’m going to remove some of the original plaster to expose the lath so the medallion will have its own keys. It is the right way to do it.

2 comments:

St. Blogwen said...

Hooray for detective work!

Do I understand rightly that the lath-imprinted plaster all over the back of your CraigsList medallion was a piece of the ceiling it was originally attached to? Great job getting it off. Whew!

Kate H.
www.sowsearhouse.blogspot.com

Greg said...

Yes, that is correct. It is almost like someone cut it out of the ceiling.