End grain join with different species

[Rick Herrick]

I recently made a bedroom dresser for my daughter.  Mostly white oak but with a Peruvian walnut top.  She would like a matching mirror, using both woods.  She found a retail mirror showing how she wanted it, drawing below.  For those stiles can I do an end joint without any issues down the road?  I didn't know if the behaviour of each species could cause a movement issue later?  Any thoughts?

 

[Michael Kellough]

You can count on different amounts of seasonal movement. Even joining different boards from the same species will result in different degrees of movement.

 

[hdv]

Oops, accidentally cancelled my earlier reply before sending it...  [embarassed]

I wouldn't relay on glue to keep it together. Just like Michael says, the differing expansion coefficients will get you in trouble.

But the Japanese have invented multiple types of joints that could be applied to a situation like this. You could take a look at some of those.

But maybe a more simple approach would do too?

Here's two examples that spring to mind. Of course you would need to adapt them to your situation.

[attachimg=1]

You could make a half-lap joint with one or two through dowels.

[attachimg=2]

I like this second one quite a bit. You could make an inline connection of two pieces based on that idea.

 

[Rick Herrick]

I had planned on just using dominos and glue.  I guess I have nothing to lose.  Worst that could happen is if it gets ugly, just make a new one.  I guess I have the option of using all white oak and just using a dark stain/oil to replicate the walnut coloring on top. 

 

[Packard]

A half lap is easy to make and provides a large glue area.  It would be quite strong.  You could peg it with dowels in contrasting wood.

If you want an even stronger joint, then a saddle joint doubles the glue area.  It would be stronger than the wood itself.  Indeed, the  half lap would be stronger. 

You usually see those joints at corners or T-junctions, but there is nothing to preventing using it for a butt joint.

I've made both of these joints on the table saw.  With a tenon jig for the saddle joint and with either a tenon jig or a dado head for the half lap.  You could do the half lap with a router also. 

For that application, I think I would use the half lap.  I definitely would prefer it over a floating tenon or dowels.  It would be easier to clamp than those joints.

As a rule, according to everything I've read, differences in expansion becomes a concern when the joint is over 3" wide.  It does not  look like it would be a problem to me.  I've made Shaker drawer fronts and doors using both half lap and saddle joints.  The vanity in my bathroom is about 12 years old and has saddle joints.  It is about 3" wide. 

 

[hdv]

If you are not yet experienced in making more complex joints by hand, then maybe the option of a half lap joint with through dowels is your best option. On the other hand, if you have ever made dovetail joints by hand, then the other type really isn't that hard to make. Try it on some scrap first and you'll see that it really is quite doable. Just don't cut the part to length yet. That way you can always redo your attempt if some mishap happens. Start with the tail and mark the "cut out" on the other piece after that.

 

[Crazyraceguy]

As narrow as those pieces are, I wouldn't worry too much about wood movement. Simple butt joints with a couple of Dominos will be fine. It is after-all a mirror frame, not a door, no one is going to slam it shut.

 

[Michael Kellough]

Sorry my reply was so brief.

The joint won't fail even if it's glued end grain to end grain as long as the stress on the joint is minimal.
The more stress the more you need a mechanical joint. Domino is probably enough in this case.

What I met say is the edges won't stay as perfectly flush as they were at the time of completion.
At this small scale the resulting bump at the joint in another season will be minor. Up to you whether that is a problem

 

[Cheese]

Rick, I'd just use a Domino or two, I expect it will be fine. If you want to go the belt & suspender route you could also pin/screw the Dominoes or if you like contrasts you could do something similar to this route.  [smile]  It's interesting to note that the maple plugs look lighter than the maple flooring and the Jatoba plugs look darker than the Jatoba flooring but the plugs were actually cut from the same material...its the contrast that affects the color of the materials.

[attachimg=1]

 

[Packard]

I don't use a domino, but I do dowel often.  For me, the straight run is going to be easier to clamp a half-lap than a butt joint no matter what inserts you use (domino, biscuit, dowel, floating tenon, etc.).  The strength is going to be adequate regardless of which joinery method is chosen from the above.

On a table saw, the half-lap is a cinch to execute.  It works equally well going straight, in corners or T-joints.

Most people (and that includes most daughters) will not appreciate the difference in the joinery method.  It is rare that people are impressed with the craftsmanship involved.  It  appeals to the woodworker more that to the recipient of the gift.

I do like the appearance of the Amish looking half-lap plus pegs.  I have a mortising machine and I prefer square pegs, but dowel pegs look good too, especially in contrasting woods.

If I am pegging the joint, I forgo the clamping entirely.  I  drill pilot holes where the pegs will go and  drive short pan head screws in, in place of the clamps.  I  remove the screws once the glue is dry and then add the pegs.

 

[Rick Herrick]

Trying to understand the responses.  The four corners themselves, are not the issue.  They will be the same wood on both ends so I will use glue/dominos like I would normally do.  The concern are the two stiles.  Each one will be composed of about 8" of walnut, end joined to about 16" of white oak.  I don't want half laps or pegs, or anything like that, because they will look odd to me.  I don't want the half lap because you will see in from the side.  My real question is that once I fashion a stile out of two different types of wood, how much of an issue will that be.  I assume expand/contract will be different but the width will be about 2.5-3" so hopefully I won't see much, if any issue.  If it violently splits apart then I will try something else.

 

[hdv]

I am not convinced a butt joint will be strong enough over longer periods of time. Not when it comes to a mirror. But that depends on how large the mirror would be. With everything glass I am a belt-and-suspenders type...  [embarassed]

A domino would probably hold up. Not sure though. You might try a mortise and tenon joint if the frame were thick enough, but it probably isn't. Possibly with a dowel just through the back so you wouldn't see it from the front.

The easy version of that would be a dominoed butt joint with a dowel through the back of the frame into the domino on both sides of the joint. That would be invisible from the front too. Like I said belt-and-suspenders...  [wink]