My friend came over and helped clean the grout. We wet it down, then scrubbed with a tooth brush sized nylon brush dipped in haze remover, then mopped up. I will see what it looks like tomorrow when it dries.
The Mapei rep advised
this stuff:
http://www.mapei.com/us-en/product-detail.asp?IDProdotto=1005815&IDTipo=162&IDLinea=102
Have you ever used it? He said it will seal grout and color it. I read the
info sheet and it may not be solvent tolerant. What do you guys think?
Part of me says it is epoxy based and will be like having epoxy grout. Part of me wonders if it will just sit on top like paint and end up peeling off... The guy in post #8 of
this thread tested it and was able to peel it up.
The colored sealant is good stuff. Dakota just hasn't used it so he doesn't know
It is a real pain to put on and get right though. I have done it a few times and don't like doing it. I have, and would recommend, hiring a good painter to paint the stuff on if you go that route. The colored sealant will seal the grout and it will be exactly the color you buy.
The enhancing sealer should also darken your grout and might get it to the color you want. Do two coats. First will absorb real quick, wipe up any that is on the top of the tile. Do a second coat and you will find it uses less and most beads up on the surface. You will want to reseal the grout fairly often if you want it to stay good. However, these sealers don't really protect against oils. Oils can and will still penetrate. These sealers are a penetrating sealer. So, they soak down in and try to fill the voids so other crude can't get in but they can fill everything and they wear out.
Color sealers are what is called a "topical" sealer. They don't soak "penetrate" in but rather put a layer over the top and prevent the crude from getting in and keep it on top. I am not certain how the color sealers act when they encounter solvents though, not sure if they wash away or hold up. Solvents by the way can also wash away penetrating sealers.
Now, the mapei rep recommending mineral spirits and linseed oil. That is sort of an old school way of sealing portland cement stuff. The mineral spirits would be the solvent carrying the "sealer" linseed oil. This would also darken your grout and "protect" it. It would be similar to the penetrating sealer but may protect better than the commercial penetrating sealers in a garage environment.
Basically, just know that this is a garage and if you plan to use it like a garage the grout will NOT remain perfect. Most people can't keep grout clean in the kitchen.