[TS3660]

I know this isn't woodworking but I figure you are a bunch of smart people and many are DIY'res like me. I am building an outdoor kitchen. The countertop is natural tennessee sandstone and is 2 1/2" thick. What should I use on the joints? By "joints" I mean the seams between the stone pieces, the seams where the stone meets the brick backsplash in back, and underneath the stone where it sits on top of the brick. I've been told non-sanded grout, colored caulk, colored mortar, and nothing.

 

[cabinetman]

That's some nice looking stone. I would first try to get that miter closer. If you are looking for an adhesive, I would use a clear Polyseamseal adhesive caulking. You could use GE Silicone II, but I'm not happy with the clean up, and the fact that it stays sort of spongy, and attracts dirt.

For a fill for any joint gaps and to the brick, I would use a colored non sanded grout, and when that cures, use a stone sealer on it. It works good for doing butt joints in marble, and granite tiles.

.

 

[TS3660]

That's some nice looking stone. I would first try to get that miter closer. If you are looking for an adhesive, I would use a clear Polyseamseal adhesive caulking. You could use GE Silicone II, but I'm not happy with the clean up, and the fact that it stays sort of spongy, and attracts dirt.

For a fill for any joint gaps and to the brick, I would use a colored non sanded grout, and when that cures, use a stone sealer on it. It works good for doing butt joints in marble, and granite tiles.

.

Thanks for the input. That miter is as close as it's going to get because it's butted on the bottom because it's not cut square to the top. As far as sealing it, I have looked into that too and there's two different thoughts. Seal it and don't seal it. I think I will eventually seal it but I can't find food grade seal. Some say if I don't seal it I will be fine. If I spill something, scrub with water and powdered soap, like Boraxo. I dunno.

 

[cabinetman]

Were you meaning sealing the stone, or the seams, or both? I will say if you don't seal the grout, and it stains, it's likely you won't get the stain out.

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[TS3660]

I was meaning sealing the stone. I understand now. Yes, if I grout, I will seal the grout. But sealing the stone, I dunno. The jury is still out. I'm hoping someone on here is a stone expert.

 

[mobilepaul]

The countertop is natural tennessee sandstone and is 2 1/2" thick. What should I use on the joints? By "joints" I mean the seams between the stone pieces, the seams where the stone meets the brick backsplash in back, and underneath the stone where it sits on top of the brick. I've been told non-sanded grout, colored caulk, colored mortar, and nothing.

I think I would use epoxy grout. I have never used it on an outdoor application but it's bulletproof on every indoor app that I have used thus far and I know of people using it on outdoor kitchens.

http://www.troublefreepool.com/any-experience-with-epoxy-grout-on-tile-counter-of-bbq-t37994.html

 

[Hammer1]

Stone installers use special clamps to pull joints together and try to avoid larger gaps like you have. This joint should be sealed to keep everything from lodging in the joint. There is no concern about "food grade" sealants but plenty of concern if an area is open to collecting nasty stuff. There are many colored caulks that can be used, formulated for stone counters and exterior applications. Take a look around this site, contact them for a recommendation. Don't try to do it with big box or ordinary caulks.
https://www.regentstoneproducts.com/item_detail2.aspx?ItemCode=CEMABONDSILI

 

[Bill White 2]

Do you have a granite installer nearby? If so, I'd be wearin' him out with these questions.
Surface sealing on sandstone would be a prime objective if it were my project. That stuff if porous, and as beautiful as that top is, I'd not want it stained.
Bill

 

[Sgt. Spatula]

I really think it's feasible to take a little diamond blade angle grinder and fix the fact that it's not cut squarely. Just touch the bottom half of it with the diamond blade, adding water. Don't even try to come close to the top, you don't want to nick that sweet edge.