Will Grout Stick To Foam?

[crokett™]

long story short, I did a faux stone wrap on our kitchen island.  the product I used after ordering samples from a couple places is a cast foam.  it looks and feels amazingly realistic.  There were various technical difficulties with the outside corners.  For one, unlike wood trim that has the same profile all the way along, when you cut the panel to miter an outside corner and then go back to cut the matching miter on the other side even if you are 1/4" off the profile no longer matches because the stone is irregular.   For that and other reasons I decided to leave a gap and come back and fill it.  I'd like to fill it with grout, since it will look more  like mortar than caulk.  Will grout stick to the foam in a vertical application?  The cut edges of the foam are closed cell but not smooth.    I expect the foam to be dimensionally stable. Is there such a thing as sanded caulk?  I'd be using siliconized grout from a caulk gun.

[Roly]

long story short, I did a faux stone wrap on our kitchen island.  the product I used after ordering samples from a couple places is a cast foam.  it looks and feels amazingly realistic.  There were various technical difficulties with the outside corners.  For one, unlike wood trim that has the same profile all the way along, when you cut the panel to miter an outside corner and then go back to cut the matching miter on the other side even if you are 1/4" off the profile no longer matches because the stone is irregular.   For that and other reasons I decided to leave a gap and come back and fill it.  I'd like to fill it with grout, since it will look more  like mortar than caulk.  Will grout stick to the foam in a vertical application?  The cut edges of the foam are closed cell but not smooth.    I expect the foam to be dimensionally stable. Is there such a thing as sanded caulk?  I'd be using siliconized grout from a caulk gun.

Sanded caulk will be in the ceramic tile section by the grout.   It is used to match the tile grout.   Comes in many colors to match the grout.   Roly

[crokett™]

Sanded caulk will be in the ceramic tile section by the grout.   It is used to match the tile grout.   Comes in many colors to match the grout.   Roly

Is this the stuff?  This is what I was looking at, it came up when I searched for sanded grout in a tube:

https://www.homedepot.com/p/Custom-Build.../204984830

[Stwood_]

Yes..

[crokett™]

thanks.

[FS7]

thanks.

FYI, in my opinion that's one of the single best products Home Depot carries. I have used that sanded caulk in many applications beyond matching grout - it is durable, easy to clean, and seems to resist mold and mildew a lot better than silicone. It also cleans up with water instead of alcohol.

[crokett™]

I was thinking last night and figured out what I should have done to get a better match on these corners. Since they're outside corners, all that really matters is the outside edge meeting. What I should/could have done is cut one side. The remaining side with the angle cut the wrong way, remove most of back of the correct miter with a saw, then use a rasp to clear the rest out to the edge and leave the cut profile intact. It's foam so wouldn't have taken long. The actual miter angle wouldn't matter that much so long as the back of it is relieved enough to get the outside edge to close.