Help with crossgrain joining table top.

[baycal94566]

Hi. I have a table top design that has a few cross grain joints in it. The design is final, pieces are already cut, so I can't change it. I am wondering if on all the joints if i leave one of the dominoes unglued if it will help. Or maybe even glue them all but use the widest setting? As an example on one of the joints its a 10 inch wide board. What if I did two dominoes glued in and then a third that is glued into one side but not the board that will expand laterally. Or what if I alternate gluing every other one. Hope that makes sense.. Any help here is greatly appreciated.

JD

 

[Stone Message]

Hi JD

If what you describe is a breadboard design (a piece that goes across the end grain of jointed boards) then use the narrow setting for the centre domino and the (DF 500) middle setting for the others. This will allow some movement as the wood shrinks across the grain.

I know that you said you are committed, that is fine, and it might still allow you to leave the wood in the room where the finished piece will live for a couple of weeks before final trimming, joining and planning/sanding. This may help to reduce the worst of the effects of further drying out.

Peter

 

[baycal94566]

Thank you for your time Peter. It is not a breadboard design. It's much more intricate than that. Think Labyrinth. Ok maybe not that bad but it has several Cross grain joints.

 

[Stone Message]

If you are building up an area using a pattern of pieces like a labyrinth then you may have some fun ahead. I do not know the actual design (perhaps you could provide a sketch or photo) but the wood may want to shrink (sometimes expand - but less likely) across the grain. If you have multiple cross grain joints then they should, in general, even out the warp factor (dear old Spock) but you may be more likely to see shrinkage cracks.

The latter is very easy to deal with during a touch up or re-application of finish perhaps at the 2-3 year point.

My experience is based on a series of tables that I made a very ling time ago that had a spiral design. They were not my best bits of work !

[attachimg=1]

Peter

 

[baycal94566]

H[attachimg=1]Here is the tables sitting raw no dominoes punched just laying how they will be.. Not much I can do now except leave some of the domino holes larger hoping they help a little with expansion. The buyer wants a rustic beat up look so maybe that will help but the finish will need to be re applied for sure.

 

[tiralie]

Any help here is greatly appreciated.

Looks like you're well on your way but other than veneering, which is the traditional way of addressing cross grain I can't think of any thing else.

The buyer wants a rustic beat up look so maybe that will help but the finish will need to be re applied for sure.

Not sure why the finish will have to be reapplied...because of the distressing?

 

[Rick Christopherson]

Not much I can do now except leave some of the domino holes larger hoping they help a little with expansion.

No, leaving tenons loose is not going to help you. You need to glue this up tight and hope for minimized expansion.

A cross grain joint will survive significant expansion force, but very little contraction. So your table will be far more survivable if you start out drier than normal. Keep your stock dry. Keep your glue joints tight and strong. Finish all side of the table to minimize the amount of seasonal change. If it's going to blow up, it should do it in the first season.

 

[baycal94566]

The finish will need to be re applied because the top is probably going to crack, along with the finish. even tho it will be a marine grade finish it is not bullet proof.

 

[mouppe]

Furthering Tim's suggestion, I would glue it to a plywood or MDF substrate leaving a small gap- perhaps 1/32"- between all the pieces. The pieces should be glued in their middles leaving the edges free to expand and contract. It will also leave no problem with the finish.

If you don't want to see the substrate you can lip the outer pieces or add a solid wood edging.

I can think of no solution with the domino that will mitigate the seasonal movement problem and still look good.

 

[Jonnio]

Hi, I make hundreds of table tops from reclaimed wood for pubs and cafes. Whenever we do the breadboard end as peter mentioned theres trouble. No matter what you do with or without the dominos or how much you dry the wood out (though it does help) the width will always shrink more than the length. The worst case for the customer is that the top buckles or falls apart. At least if it is laminated to a sheet of something stable you will only have to deal with the gaps and re finish. Plus it will add to the beaten up look while still being useable. Good luck..