floor grout -- why did I make such a mess?

I am tiling a hearth with 4X4 slate tiles. I installed the tiles over a month ago and sealed them twice.
Today I grouted the hearth and it was a total mess. I used a float to work the grout all over the hearth and this seemed fine. Then I got up a reasonable amount of grout with the float. The grout directions said to wait 45 minutes at that point so I waited... then I started removing the grout on the tiles using spones and rags and it was a complete mess. None of the grout was dry (maybe this is correct---this is my first attempt at tiling) and I had to work like crazy to get the grout off the tiles.
At this point all of the tiles are clean, which is nice, but there is hardly any grout left in the tile joints. This is because of the scrubbing and rubbing that I had to do to get the grout off off the tile faces.
I am sure that I did something wrong because the grout lines are pretty ugly, not smooth, etc.
I am suspicious that I removed the grout too early and that I should have waited until the grout in the joints was hard. Is this right? Any other ideas here? The sealer evidently worked because when I look at the tiles now I see grout only in the joints.
Assumign that I can figure out what I did wrong, I want to re-grout the entire hearth so that the grout lines look good. Can I just put another layer of grout on top of the existing grout? THe hearth will not be a heavy traffic area. I am going to place a woodstove on it when I am done.
Thanks, mh
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???
When you're done putting the grout down there should be no more than a thin hazy layer on the tiles. Then you can sort of wet that and work it with a sponge and it comes off.
You don't seal til the job's all done.
(The above info may be wrong but it's my experience)
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snipped-for-privacy@yahoo.com wrote in message

I was told to wait three days before sealing, that could be wrong too, but it is what I was told.
Cheri

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Cheri wrote:

With slate (unlike ceramic) I was told that I needed to seal before and after grouting because the slate would otherwise absorb grout.
mh
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that may be true with slate. I know it's one recommended practice with saltillo tiles. Where you went wrong was letting the grout "dry" before cleaning (even if was only 45 mins). My method looks something like this and I've done more than a few hundred feet of the stuff. I grout using the float and do my best to minimize the amount of grout actually on the tiles. For smaller tiles, this can be difficult but on larger ones, you can darn near keep the tile clear of any grout. I do around 9-12 SF at a time only cause that's as far as I can reach generally. Once I have them all grouted, I take a sponge with two buckets. Both start out with clean water. I wet and wring the sponge out and start cleaning the tiles. I work at the grout line at a 45 degee angle. When the sponge gets dirty, rinse in bucket number 2 and then refresh the sponge in bucket number one. Keep at it until you've got as much of it up as possible. You can really smooth out the grout lines as well although you don't want to add too much water to them. Let it dry. Then go back and wash it again as there will undoubtedly be some haze. For really bad hazing, you may have to use a bit of vinegar to help with the cleaning (although there are other acids out there to do the same). Cheers, cc
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James "Cubby" Culbertson wrote:

Ok, this makes sense. Thanks! I like the two bucket idea as in fact I quickly ran into a dirty bucket and did not have another in the house. My tiles are 4X4 and I can certainly do a better job of not getting grout all over them.
mike
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Mike wrote:

Sounds like you tried to be too neat and your grout was too wet. You just slop in on all over making sure it fills all joints, then wipe off the tiles with a rubber squeegee, I wouldn't call it a float but probably a lot of people do. The squeegee should just wipe the tile tops and leave the grout in the grooves. When you get it all the extra grout wiped off, you go over it once more with a clean squeegee. Wipe with a sponge after you test the grout and the sponge does not lift the grout. Wiping with a sponge should remove just enough grout to be a hair lower than the tile. It will naturally be a very shallow U.
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