Walls and Ceilings - Keenes Sand Float Finish help

Good morning, Tightcoat here has been helping me with some plastering projects, and he has been very helpful. I am a little stuck at the moment, and I don't know if he is around today or not, so if anyone has experience with keens, please feel free to jump it. Thank you very much. I just posted this same message on wconline, but it is not always very active, due to the urgency of my issue, I posted here as well. Thank you again.

I have keenes open on my wall right now, and am having some problem, if anyone has a few minutes to help, It would be wonderful, Thank You very much in advance, here is the information about what I am doing and the problem:

I am top coating a wall with Keenes that I had to patch in several areas. I am looking for a sand float finish. The wall is structurally sound and was thoroughly coated with plaster bonder.

I trowled in a coat of Keenes over the full wall (about 8'X10'). I do feel like it went on thicker than it should have. I mixed the Keenes by dry weight, 1 parts Keenes, 2 parts lime, 8 parts fine sand, per usg directions for a Keenes sand float finish.

Here is my problem: The first coat went on pretty well, however I was left with low spots that I was having trouble getting trowled out. So I left the Keenes firm up a bit, once it was more first, but not quite to where I think it should be to float it out, I trowled over it with a fresh batch of keens. I have been able to remove most of the low spots and feel the wall is pretty level.

However, I keep getting trowel marks in my work that I just can't seem to get rid of and get a smooth surface. I assume that the surface needs to be pretty good and flat before you float it out?

I have been keeping my trowel very clean, I trowel in and back right away, and still have a trowel marks.

I am thinking about getting the wall wetter with a spray bottle and then trying to smooth it out, otherwise was considering trying to take a mag float to it. Would it be better to do it while it is still fairly wet, or should I let this firm up more and then try and get this evened out with a mag or red float?

I have other walls that I have put a base coat of plaster on, but that was a lot thicker, and I wasn't using keenes, on those walls, I embedded metal grounds, and was able to strike off against the grounds. Those walls came out pretty nice and flat. However, since this wall was already flat, and I just wanted to top coat for the sand finish, I did not put and grounds in it, and it is too large for me to strike off with any of my tools with no grounds to strike against.

I will watch for responses, and respond asap to any questions you have.

Thanks again,

Jamie Dolan

You are probably done by now and I bet it worked out just fine.
It's always better to have a wall straight and level before you try to float it but you can do a lot of good with the float. It takes a bit of practice but you can move the mud a bit with the float and you can use a little more pressure in one place and less in another to even it out some too. If you have a good straight 1 X 4 two or three feet long you can wet that and slide it over the wall or ceiling holding it almost but not quite flat and that will flatten out some of those trowel lines. You are after straight and flat not necessarily perfectly smooth before you float it
Once you have an area floated to you satisfaction do not keep going over it just progress to the next section. Consistent circles a foot or so in diameter is your floating motion. Don't even take the float off the wall unless you need to wipe some excess mud off the float or need to wet it again to keep from pulling and dragging.

But like I said. I bet you are finished by now nd it turned out fine.

Let us know.

When doing this finish you should be troweling it on a 45 % angle unless its a very small area. You also float it on a 45 % angle.

Thank you both for responding, I think that some of my keens may not be quite as set as it should be for floating, as I was lifting off a bit of mud in places when I was floating. These are some photos from the floating I just finished, taken about 10 minutes ago.

I am not sure if I should try to re-float it again in a while and see if I get a little better pattern or if it is done right now and I should not mess with it. http://www.dolanhosting.net/jamiedolan/plaster/IMG_5719.JPG
http://www.dolanhosting.net/jamiedolan/plaster/IMG_5713.JPG

Thanks again
Jamie

I hope it is not too late. That is one good thing about Keeenes is it is slow setting and you have a lot og working time if it doesn't get too dry.
It looks like you are taking a swipe with the float then lifting it off and taking another swipe. To match the finish you have you want to rub the surface in continuous circular motions never taking the float off unless you need to wet it again or if you need to wet the wall. When I float it is a two hand operation. I hold the float in my left hand mostly and a water brush in the right hand. I'm right handed. Floating is when my right arms gets to rest. I float in circles and when the wall needs a little more dampness I flip a little on from the brush. Yes you can use a spray bottle.
Hold the float flat to the wall
Try this again and rub gently to start with and use more pressure if it helps and I think you can take out the trowel lines and get a finish like your first pictures show. Practice and you will get it

I hope it is not too late. That is one good thing about Keeenes is it is slow setting and you have a lot og working time if it doesn't get too dry.
It looks like you are taking a swipe with the float then lifting it off and taking another swipe. To match the finish you have you want to rub the surface in continuous circular motions never taking the float off unless you need to wet it again or if you need to wet the wall. When I float it is a two hand operation. I hold the float in my left hand mostly and a water brush in the right hand. I'm right handed. Floating is when my right arms gets to rest. I float in circles and when the wall needs a little more dampness I flip a little on from the brush. Yes you can use a spray bottle.
Hold the float flat to the wall
Try this again and rub gently to start with and use more pressure if it helps and I think you can take out the trowel lines and get a finish like your first pictures show. Practice and you will get it

I re-floated it again once I got this message from you. It is still floating out just fine. Actually the bottom area of the wall that I troweled in last, close to 6 hours ago is still a bit wet, and I think it needs a smidge more time before I can float it properly. I can't yet hold the float to it firmly without taking off too much mud. Will try it again very shortly.

As for the majority of the wall, I am now able to create the larger swirl pattern like they used elsewhere in the house. You can see the swirl patter on the ceilings in the rest of the house, but the walls have had too much paint over the years, and I'm not sure if they were swirled or just troweled out with a sanded finish. Is it normal to do a swirl on the ceiling and just sand on the wall?

My only concern, as this is drying, I have seen just a couple small cracks at some places by the edges, should this be a concern at all? or will these hairline type cracks be self limiting and get covered with paint? I am around 60 degrees far. and 35% humidity.

Thank You again,

Jamie
p.s. Just out of curiosity for the future, if I was going to make a wall a smooth finish, would I float it at all or would that all be trowel work? (using keenes)

You might be able to close up those cracks by dampening the wall and floating it again. What is probably happening is the material is drying out without setting. That is one of the natures of Keenes. There are some things you could have done to get it to set but not now. If you float it and it closes up the cracks that's good. If you float it and it smooths it out instead of raising the sand and closing the cracks then quit and hope for the best.

Yes to do a smooth wall is trowel work. A little water for lubrication, a clean trowel proper pressure and good timing will make a wall so smooth it shines.

Probably the walls and ceilings were done a little differently. Same mix, same tools and just different strokes with the float.

You might be able to close up those cracks by dampening the wall and floating it again. What is probably happening is the material is drying out without setting. That is one of the natures of Keenes. There are some things you could have done to get it to set but not now. If you float it and it closes up the cracks that's good. If you float it and it smooths it out instead of raising the sand and closing the cracks then quit and hope for the best.

Yes to do a smooth wall is trowel work. A little water for lubrication, a clean trowel proper pressure and good timing will make a wall so smooth it shines.

Probably the walls and ceilings were done a little differently. Same mix, same tools and just different strokes with the float.

The tiny cracks near the top of the wall disappeared and the sand all raised to the surface.

We are very pleased with the swirl pattern I ended up doing, it is very similar to what has been done on the ceilings throughout the home, as you saw in the prior photos. I am going to run a skim coat of Keens like this on all the walls, ceilings, and sofit boxes in the kitchen, so it is all going to match.

I only ran into one semi major problem as I was finishing the floating. An area that we had just patched did not adhear to the keenes, and when I went to float it, the keenes just cracked and fell off.

I know how to fix by going back and applying plaster bonder and reapplying keenes, but don't understand why it happened.

There was a good size area around a outlet box that was patched, and filed flush to the old wall (so it was full filled with plaster and bonded with plaster bonder to the old wall edges and was flush with that old wall). The area was not really raked well before it set, but was not polished smooth either.

The patch on this one was done with National Gypsum Kal-Kote Base. The patch was made well less than 24 hours before I applied the keens, so I didn't think I needed plaster bonder.

Was this caused by me not roughing up the surface of the Kal-Kote patch enough before it set? What else would have caused the bond between the fresh set Kal-Kote and the Keenes to fail?

I have a lot of sqft in the kitchen where I will be bonding Keenes to Kal-Kote. I can just apply plaster bonder to all of my Kal-kote before I apply keens, I just understood it to be unnecessary if the Kal-Kote was fresh.

I will be starting in on laying Keens for the rest of the kitchen in the next day now, I just have to finish a bit of base coat first. Are there any special pratices I should observe to help avoid cracking? (extra moisture?) Or accelerate the set? I read I can add USG molding plaster to the Keenes mix to accelerate the set, I did throw a cup in one batch today, but it didn't seem to make a lot of difference in my set time.

I will get that area that broke off plaster bonded and filled back in with the next batch of Keens I make up, then I will post some new photos here.

Thank you,

Jamie

Here are a couple photos, not the best photos, but something:

http://www.dolanhosting.net/jamiedolan/plaster/IMG_5720.JPG
http://www.dolanhosting.net/jamiedolan/plaster/IMG_5721.JPG