you can push more mastic into the inter-tile gap now, and later grout on top of it.
(i didn't read the whole post carefully, so i don't know if you have other problems) . Stand by for bill v or others who may comment on other things.

I'm interested to hear what Bill says. I've never used mastic, only thin-set, but I thought it was a good thing not to have a lot of thinset between tiles, and I've always attempted to clean up the joints before grouting. I thought excess thinset in the joints could bleed through and affect the color of the grout, among other things.

My inexpert guess is that you don't need an adhesive there where you aren't putting on any tile that needs to be adhered!

what you wrote is all true, but she is asking about absence not excess.

What was the Backer Board you set those tiles on? If it was painted drywall or Denshield the mastic could still be wet behind the tile.

You mention Hood as where the tile went. Are the tiles attached to the wood itself? Is the wood lacquered?

Pictures here would help.

If the Mastic is on a large tile and is stuck to something semi waterproof the mastic will only dry on the corners. This is not good....

JW

It is in fact on the wood itself, and unfortunately, yes, it was finished wood. I had read that it was OK to put it directly on the wood because it won't be exposed to water.

That is a lot of moisture to leave under your large tiles in my opinion. I'm not sure if you would do more harm removing them than good leaving them but my gut says to get them off.

If it was me removing the tiles at this point I would cut a small square in the center of the tile and remove. Then pry out from there.

If you where to leave these tiles for a long spell perhaps the mastic will dry out. Will the wood be damaged by the moisture I don't know.

I'll see if Bill is anywhere and can offer up some better advice.

Stand by.

JW

standing by, hoping for the best. I guess I'm hoping at this point that the fact that it is a hood, and therefore presumably exposed regularly to heat MIGHT mean that the mastic will eventually dry. Maybe I should not grout for a long time?

Oy, the one thing, I attempted to do myself.....

for a number of reasons, i wouldn't worry about the mastic
(that might take a long time to dry out).

one can now safely add mastic into the large gaps, between tiles, and leave room for grout to be added later. The Main Thing here is to make grouting easier and more likely to proceed trouble-free and give good results, that you will be satisfied with. Only a DIY can do this. A pro would not come back for one more little step when they could finish it all off in one go. So, this is a happy time, for you. You get to do a better job than a pro might do. Be happy. Don't worry.

Davidrol: Thanks for the encouragement!

You absolutely do NOT want to put mastic in between the tiles. You use grout between the tiles. I am very concerned that you tiled directly to the wood. Wood expands and contracts, which will cause your installation to fail. It is true that you can use mastic in a dry installation, but that is not the issue here. The issue is that you tiled directly to wood.

I would enjoy it while it lasts. Sooner or later it's going to come off. Mastic, thinset, epoxy, silicone-- doesn't matter. You can't st tile over dimensional wood, and eve moreso with a finish on it. I hate to put a damper on this party, but this will not last.

Mr. Bill V is a busy boy. I posted the question on his FB page and I think he said it needs to come down.

I would hold off on grouting till next week... or next year!

OK...so sooner or later it will fall off. I take it that it MIGHT be quite a while before it does. And when it does, is it likely to be repairable? I mean would I be able to scrape off what I needed to, put some kind of thin backer board on it and tile it again? if so, sounds like I should, as Bill says enjoy it while it lasts, and plan on redoing it properly when I need to.