Help with cross-grain situation

[Dan Mages]

I need help with a cross grain and inlay situation. Here is the deal. I will be inlaying a 12x12 granite tile (1/4 inch thick into an ash board (3/4 inch thick). I will be framing out the granite with some 1/4" thick x 1" wide walnut burl. Should I be concerned about cross grain on this inlay? Any tips or advice??

Thanks!

[David Rose]

Dan, an RH (relative humidity) change of 20% will cause a bit over a tenth of an inch of shrinkage or expansion. That could cause problems not only with the board to tile, but also the trim to the board where crossgrain exists. One way or another you need to allow for that much movement if your RH can change that much. My shop can be as high as 60%. The house as low as 20%. I would have to allow about 1/4" over the 14".

Would it be feasible to attach the center of the tile to the ash panel along the grain, then the trim to the tile and not the panel? That way the trim could float over the main board.

David

[Dennis Peacock]

Dan,

Wood movement would be my first concern. As David R. has already pointed out. If it were me....and this is just me....I would make my joints in the "frame" as tight as possible and then spline joint the corners with some 1/4" maple as as accent piece. With the splines glued and the miters tight, you would only need to allow a small amount of space for movement of the total frame that would be around the stone surface. Seal every edge of the wood with a good oil poly to slow the mositure effects on the wood and help in stablizing the wood around the burl frame. Make sense?

[David Rose]

But... if you attach that frame to the panel, the panel *will* move. Are you not suggesting gluing the frame to the panel?

David


Dan,

Wood movement would be my first concern. As David R. has already pointed out. If it were me....and this is just me....I would make my joints in the "frame" as tight as possible and then spline joint the corners with some 1/4" maple as as accent piece. With the splines glued and the miters tight, you would only need to allow a small amount of space for movement of the total frame that would be around the stone surface. Seal every edge of the wood with a good oil poly to slow the mositure effects on the wood and help in stablizing the wood around the burl frame. Make sense?

[Dan Mages]

Please let me clarify. I will be setting the tile into a solid ash board. I will use my router to plow out a space for the inlay.

Dan

[David Rose]

That's what I thought you meant, Dan. I don't think you will get a lot of tile changes in dimension, but the panel *will* move to some extent. In other words, if the tile was a tight fit to the mortise, and the board expanded, you would simply have a gap around the tile. If the board contracted, it would probably split some place. The frame dimensions will change insignificantly. That is why I was wondering if there was a way to attach them to the tile rather than the board or possibly float the frame above the board. They could be a nice fit to the tile and hide any expansion gaps on the big board. I'm not sure how practical this would be to do, but I think it would work.

David


Please let me clarify. I will be setting the tile into a solid ash board. I will use my router to plow out a space for the inlay.

Dan

[Dennis Peacock]

OK...gotcha.....Yea....David has you going on the right track.!! :D

[Dan Mages]

Thanks for the advise. Here is my adjusted plan. Please excuse the crudeness of the schematic.

The 12x12 granite tile will have a 3/4 inch wide band of walnut burl on the top and bottom. I will leave a 1/4 inch gap between the granite and the walnut. I will glue the granite to the ash base with a few tabs of a silicone adhesive on the top side only. As a new design option, there will be a 4x12 piece of tartan laid in. I will use some of the leftover tartan to fill the 1/4 gap.

How does this look. Any suggestions?