# What is this joint called? Compound angle butt joint?



## mbira (May 15, 2014)

Hi folks,
I'm attaching a pic to give an idea of what I build. The long ends are generally 65" and the long end piece is around 14" and the short end piece is around 6". The end pieces have an 8 degree angle on the edges making the bottom longer than the top. Because of the one end piece being wider than the other end piece, there is also a 3 degree angle on the edges of the long pieces where they butt against the end pieces. all pieces are 4/4. 

I have always just done this as a butt joint and used two screws on each joint that are hidden with plugs. 

I would like to get more elegant with these joints and move away from screws. I'm thinking about a mortise and tennon, but I have never seen anything on doing that with an angled joint. Can anyone point me to advice on how to approach that.

I'm also open to any other tips on good ways of doing this joint. Ideally, I would like to be able to do this quickly and efficiently, but the number one concern is making this joint strong and looking great-even if it takes longer. Thank for any advice!


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## GeorgeC (Jul 30, 2008)

It would be difficult to do mortice and tenon because of the angles.

However, you could do hand cut box or dove tail joints. These would look nice.

Your last picture looks like you added dowels to the butt joint.

George


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## mbira (May 15, 2014)

Thank you for the reply. That last pic shows the plugs that I use to hide the screws. I suppose I could also do this with dowels instead of screws. 

Regarding the difficulty of getting that angle on the shoulder of a M and T joint, it seems like it would be more cumbersome getting that same angle on each inside edge of the angled box or dovetail joint? 

One thing I have noticed is that if there is a slight bow in the long pieces (these are 65" x 3" x 1"), then that three degree angle where the meet is slightly off and I need to finesse it a bit. The nice thing about the butt joint is that I can use a card scraper to get that angle down every so slightly to have a good fit.


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## Paarker (Mar 20, 2013)

If you're already cutting one angle for a butt joint why not lower the blade and cut two and there will be your tenon. don't forget to reverse the angle for the second side.


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## woodnthings (Jan 24, 2009)

*angled mortise and tenon joints*

This won't be cheap, but it will make the type of joints you need..... Or make them by hand?

https://www.youtube.com/watch?v=c18H3N_8UjM

even more expensive?
https://www.youtube.com/watch?v=Z7BOcet4ZTM


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## Zircon (Aug 1, 2009)

If you look at that frame, it is the same as a chair frame seat where the front of the chair is wider than the back and the long pieces are the sides of the chair. I have made several chairs M&T. I cut the tenons straight on the long(side ) pieces-easy-I do it with a band saw. The angled mortices I do with a router. I knock together a jig that looks like an old fashioned miter box except one side is higher than the other. then I clamp the workpiece into the miter box. The router rides on top of the miter box and it cuts the mortice. The correct angle for the mortice is achieved by calculating the difference in height between the two sides of the miter box which causes the router to ride at an angle.

Happy New Year!


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## Zircon (Aug 1, 2009)

Another thought- You might try a box joint. I just made a screw advance box joint jig that was described on WWT tips and tricks a while back. It's a really good design. Typically the back wall of a box joint jig stand straight up to make a 90 degree joint. You could make an angled back wall at the correct angle and cut the fingers a little long and trim them and end up with a box joint at an angle. I haven't tried this yet but I may play around with it to see if it works.


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