What material to use for splining a bench top?

[Larks]

I built a kitchen bench top about 2 years ago from New Guinea Rosewood and although I bought it as kiln dried, it has moved in the time that I've been away in Darwin and opened up at the joins.

I had glued it and batten screwed each join quite firmly but it seems that the longitudinal planks have shrunk more width wise than those that I have used to frame the ends have done length wise.

I did a bit of a temporary "bog" when I was home one weekend thinking it had done with moving but it has kept going a bit more. Without pulling it apart it would seem that the best fix now is to route out the join between the "framing" pieces around the edges and the longitudinal planks and insert a splining piece all the way around .

Here are some pic's of some of the openings and one end of the piece to show the shape of the "framing pieces" and my question is what are your thoughts on a suitable material for splining the joins?

I don't know if it is likely to still move a little more, I didn't think it would move much at all in the first place, so I am after any ideas on what may work best. Should I look for a soft wood - say cedar -that might work a bit like cork allowing me to compress it when I insert it and glue it so that it can still maybe expand a bit if it does open up? Or something else entirely?

http://i260.photobucket.com/albums/ii11/Larks_01/P9130046.jpg

http://i260.photobucket.com/albums/ii11/Larks_01/P9130047.jpg

http://i260.photobucket.com/albums/ii11/Larks_01/P9130048.jpg

http://i260.photobucket.com/albums/ii11/Larks_01/P9130052.jpg

http://i260.photobucket.com/albums/ii11/Larks_01/P9130050.jpg

[kc8pql]

Cross grain construction. Doomed from the start. Wood always moves more across the grain more than it does with it. Kiln drying doesn't stop wood movement.
Surface splining the joints will be only a temporary fix. The wood will continue to move with changes in humidity and open up again. The correct method would have been to use a veneered plywood center panel. Plywood is much more dimensionally stable.

Routing out the joints and filling with something like flexible teak deck caulk may work.

Edit: The correct method if you want to keep the tight joints and mitered frame all the way around would have been to use a veneered plywood center panel.

[ishmael]

Solid wood works fine for panel construction, but you can't restrain its movement across the grain. A rule of thumb is a quarter inch per foot of width, some wood more some less. If you restrain it something has to give; open glue joints or splits in the panel.

Typical ways of keeping it flat are bread board ends held with pegs in slotted holes in the panel, putting it in a frame where it's free to float, and battens with slotted screw holes, all of which allow the wood to move. Rather than try to describe each method in detail, I'd suggest going to the library or bookstore and picking up a good book on cabinet making.

P.S. I posted before your pics came up. If I'm seeing it correctly, I don't think there's an easy way to fix it. Taking it apart and making the frame with a dado and the panel with a tongue, which will allow the panel to float would be one way. And then, the joints between the frame and the panel are still going open up across the panel's width and allow crud in. This would be a good place for bread boards, and or battens, depending on the length of the bench. Unless it's quite long, bread boards alone will probably work just fine.

Pretty wood.

Good luck.

[David G]

Agreed as to the cause. Trying to cap a solid panel with a solid piece running perpendicular is always a recipe for heartache... without a bit of trickiness that that allows the panel to expand & contract independent of the cap.

Often, the easiest solution is to simply make the panel long enough and skip the cap. this results in visible end grain... which may not be the look you're after, but is far better than perpetually fighting new cracks.

If you're gonna cap, you'll need to incorporate the techniques discussed in the following link:

http://www.woodweb.com/knowledge_base/Breadboard_Table_Top_Ends.html?printfriendly

Good Luck,

[peter radclyffe]

it looks similar to iroko, you could glue spline some battens in

[StevenBauer]

Slick Seam?

;)

:D




Steven

[ishmael]

In my experience, splines between the boards of a panel make little or no difference. If a wide panel is restrained it will come apart. It's just a force of nature. The only thing which prevents it is allowing the wood to move.

P.S. One thing that does help to keep a panel flat, unless you are trying to show off some grain which doesn't allow it, is to alternate the growth rings, one set curved up, the next curved down.

Two cents, from fifteen years of doing this sort of work commercially. It's been awhile, but my memory isn't completely shot. LOL. As Dave mentioned, it might be fine with no frame, but you still have to figure out how to fasten it to the legs or the trestle underneath. Figure out a way to let it move.

P.P.S. A way to cut the tongue on a large piece like this is with a router. It's too big to lift up and do a credible job with a table saw on the ends. Not without some help.

[kc8pql]

In my experience, splines between the boards of a panel make little or no difference. If a wide panel is restrained it will come apart. It's just a force of nature. The only thing which prevents it is allowing the wood to move.

Agreed. (cabinetmaker for the last 40 years)

[Larks]

Thanks for the responses all, I'd kinda realised that I'd done the wrong thing with the framing around solid planks. This is our kitchen island bench and the last time I'd done one similar was with jarrah framing and a stained ply centre, this was an attempt at being a bit more "refined" than the ply. I didn't think of a veneer finish.

So, if you think the splining may be a wste of time, is pehaps sikka flex or something similar the way to go?

[ishmael]

Personally, if you aren't going to rebuild it I'd just let it be. Putting goop in the seams isn't going to stop the movement, and in a year or two will be messier than just letting the cracks open and close.

Two cents.

[Paul Girouard]

What about cutting the "panel" free went rabbiting it on all edges , then make a new "outer" frame thats grooved to accept the rabbited panel. You could put a slight radius on the rabbited top edge to give it that panelized look , and allow room via the grooves to allow for wood movement. The border could be a disimilar wood in color.

A lot of work , BUT .................

And yes you'd have a crack , but a "purposed" crack.

[RFNK]

When I worked in PNG I heard people warn against taking furniture back to Oz due to problems associated with going from such a humid environment to the relatively dry climes of southern Oz. However, having worked quite a bit with PNG rosewood since, I'm surprised to see that it's so prone to instability as it's such an oily timber, a little like teak. I've actually been thinking about using it for the new farmes in the Twister - it glues really well and it doesn't rot so it should be good for the laminated frames.

I think you're stuck with this problem unless you rebuild that part of the benchtop. Could you redesign with breadboard ends to accommodate the instability? Rick