Making an invisible joining

[rudy de haas]

I have a 2.25" x 17' 6" piece of cedar trim that's a just above head height and in plain sight for anyone coming onto the main floor. I'd like to
replace it with polished jatoba but the longest board I have is a bit over 9'. I can make two straight pieces of the right width and identical thickness and am looking for advice on how to make the joint as close to an invisible as possible.

Bear in mind, please that I do not have cabinet maker skills and do not have a machine that will make a perfect mortise/tenon type join or a good router table - but do hope to get a both a mortiser and shaper sometime this spring and if I have to leave the job until then, well I can do that.

[George Bokros]

How about a scarf joint? That is how they join long runs of baseboard, chair rail and crown molding. If cut accurately with a miter saw they are virtually invisible.

[Chris Padilla]

Scarf joint. Basically cut the two pieces on a 45 and join them that way.

[Peter Quinn]

Boat scarf. All it takes is a decent router, a quick plywood sled, a straight bit. Basically you are making a 1/8 pitch to 1/10 pitch joint along the long grain. You glue this up, if the grain match is good, fans that's a big maybe with jatoba unless vertical grain, the joint is strong and very inconspicuous.

Another option would be to purposefully block it out, don't try to hide it, make it a design feature. Put a vertical rail, 4' horizontal, vertical rail, etc to fill the run. Might break up the monotomy of a long straigh run too.

[Chris Fournier]

Scarf joint as others have recommended but I would be more aggressive and try for 20 to 30 degrees. Easy to do on a table saw with a 5 minute jig using your mitre guide.

[Yonak Hawkins]

No such cross-grain joint can be totally invisible unless it is disguised. Can you put some kind of decorative medallion or trim pieces over it ?

[rudy de haas]

Thanks!

I have scarf joints in other places but they are all cut at 45 degrees. Having just looked up "boat scarf" I see my mistake: something much shallower should work
better.

I can't do a really good grain match, but I can cut both from the same board and switch it end for end so the colors will match nearly exactly. I'm going with a board showing a "vertical" (along its length) grain pattern for this.

I don't think breaking it up would work. The main floor is one continuous open space, with the low ceiling this fronts for over the dining room part. It might be possible to have a friend with a cnc router cut letters for me and glue something like "ogne speranza, voi ch'intrate" on to cover the break, but my wife might not appreciate it.
:)

[Peter Quinn]

Regular 45 scarfs aren't really a mistake, they are pretty normal trim practice for longer runs of trim than boards allow. But IME they always open a bit, and exterior they can be problematic depending on location. I've used boat scarfs for exterior handrails, its a really good glue joint and not that hard to make. Its maybe overkill for interior, but it can be very inconspicious.

I'd be careful about the sign over the dining room. Perhaps a cheerier message would inspire a better performance in the kitchen? I do most of the cooking in my house, I'd like a sign that says "Eat what I make or eat elsewhere"

[guy young]

I agree with the miter, if you can split the thickness you can make a book match joint. Just make sure you figure the exact lenght need for the miter cut, and lay out the wood before cutting the miter. This way the book match is perfect on the outside of the miter, what you see. The grain will be a perfect opposite and blend. This is about as invisible as you get

[rudy de haas]

Can you put some kind of decorative medallion or trim pieces over it ?

Maybe a purple heart?

[Wade Lippman]

No such cross-grain joint can be totally invisible unless it is disguised. Can you put some kind of decorative medallion or trim pieces over it ?

True. Unless you get a perfect grain match it will be pretty obvious, and even then there will be a line.

I would put a couple inches of wenge between the two lengths of jatoba.

[Frank Pratt]

The fact is you are never going to make the joint anywhere near invisible. Even with perfect grain match, ie: you cross cut a board in half with a really good saw & then rejoin the same pieces, you are going to see the joint. It's not at all like hiding a long grain joint. So either decide you will be happy with an obvious joint or, as others have suggested, make it a design feature.

Sorry for sounding harsh, but it is what it is.

[Chris Padilla]

Maybe you could dovetail the two pieces together but highlight the dovetail by doing something like an Incra Double Dovetail (google it). It might look pretty cool.

[Frank Pratt]

The dovetail feature would look really nice, but may require more skill or tools than you currently have. Something as simple as a 1/8" chamfer on each board at the joint would look clean & would be easy to do.

[Pat Barry]

Seems like a simple scarf joint is all you need. Be sure to angle the scarf so its least visible. I doubt anyone will ever look close enough to notice but of course you will want to TRY and match the grain flow as much as you can.