plaster color uneven + doesn't seem to be set right

Members online

Total: 616 (members: 4, guests: 612)

Share this page

Status
Not open for further replies.
F

fantasticfarm

New Member
Hello there. I am building a home in the US. I have just tried my hand at plastering a small area and I am not sure that it went that well. I am using a product called structo lite that we have here which is a gypsum based plaster that is premixed with a perlite aggregate. I am putting it up over "blue-board" which is a gypsum panel faced with a paper that is specific to being plastered over. I taped and mudded the seams + screws with another product that I can't remember the name of + paper tape. I was planning to just use this as my finished wall because I am not too fussy about the final surface. So I just mixed some of it up with water in a bucket to a consistency that I thought was good and started troweling it on. I would say it went on at about 2-4 mm thick. maybe 45 min after I had applied it I went back over it with a metal trowel and smoothed it all to a (mostly) leather type surface. initially it was all dark grey. As it dried over the next few days a lot of it lightened, but quite a bit of it didn't. I can se that some of the areas that remained darker are over the tape joints, but a lot of them are not too. Actually there is a lot of darkness towards the bottom of the wall as well. I decided that I was just going to go over this with another coat , and see how that came out, but because I had smoothed it I decided to rough it up first. Well, that was when I found that the light areas are very soft, as in soft enough to gouge with a fingernail, and the dark areas are very hard. So, I know I've screwed up, but I'm hoping that someone who knows plaster can set me on the right path.

Thanks.
 
I think what you used is actually a base coat which is equivalent to what we call bonding here.You should have just skimmed the blue board with a veneer plaster like Diamond plaster.It may be possible to still do this providing you can control the suction the base coat will create and also it depends on what state you left the wall in.What part of the US are you in?.
 
fantasticfarm said:
Hello there. I am building a home in the US. I have just tried my hand at plastering a small area and I am not sure that it went that well. I am using a product called structo lite that we have here which is a gypsum based plaster that is premixed with a perlite aggregate. I am putting it up over "blue-board" which is a gypsum panel faced with a paper that is specific to being plastered over. I taped and mudded the seams + screws with another product that I can't remember the name of + paper tape. I was planning to just use this as my finished wall because I am not too fussy about the final surface. So I just mixed some of it up with water in a bucket to a consistency that I thought was good and started troweling it on. I would say it went on at about 2-4 mm thick. maybe 45 min after I had applied it I went back over it with a metal trowel and smoothed it all to a (mostly) leather type surface. initially it was all dark grey. As it dried over the next few days a lot of it lightened, but quite a bit of it didn't. I can se that some of the areas that remained darker are over the tape joints, but a lot of them are not too. Actually there is a lot of darkness towards the bottom of the wall as well. I decided that I was just going to go over this with another coat , and see how that came out, but because I had smoothed it I decided to rough it up first. Well, that was when I found that the light areas are very soft, as in soft enough to gouge with a fingernail, and the dark areas are very hard. So, I know I've screwed up, but I'm hoping that someone who knows plaster can set me on the right path.

Thanks.
Click to expand...

Welcome :) Get some photos up :D
 
Hey thanks for taking the time to reply. I am in the northeast. Since I posted this I was able to get a hold of a friend who is a builder + has done a lot of plastering. He told me few things that I should do differently, but the main reason for my problem is that the blueboard has been up for too long which is what led to the plaster curing incorrectly. He said to use a primer which would case the plaster to set up from the back first. He also told me that I could wet the plaster which I had already done + put another coat over the top of it. It is a base coat type material, but he is telling me that it will be fine for me, as long as I take steps to ensure that it sets correctly. Thanks again. If you have anything to add, of course it will be appreciated, but I think I am out of the woods now.
 
Status
Not open for further replies.
Top