# Plywood corner joint advice.



## roadrunner45 (21 Nov 2021)

Hello All,

I am trying to make a wall mounted bike rack from some 18mm thk plywood offcuts and would like to create a mortise and tenon joint construction , the reason for this is to make a strong bond for the rack.
Below is an image i am trying to replicate , i am hoping for some images for me to follow to achieve this joint and willing to learn the technique for future projects.

Any help/advice would be appreciated.

Thank you.


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## Cabinetman (21 Nov 2021)

Not sure that I would consider using a mortice and tenon joint in that situation, perhaps as it is but add some chunky bits of pine in the corners. The leverage on that is going to be quite high, I think I would take the backboard further so that you could put chunky bits both sides of each arm. This would also have a bonus effect of being able to screw into the wall each end and in the middle. Ian


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## Jameshow (21 Nov 2021)

I would run a 200mm run of ply along the wall then have your ply arms notched say 6mm into this then run another 200mm length of ply flat on the top screwed into both the arms and the wall board. 

This way the ply along the top is taking the strain and serves as a useful shelf for helmets and shoes? 

Cheers James


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## recipio (21 Nov 2021)

Baltic ply is hard to work by hand as it tends to crumble even with sharp tools. Loose tenons are the answer but you need pricy machines like the Domino or a router. I would suggest using 10 mm dowels either as a hidden joint or simply run in from the side arms as in the photo.


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## dzj (21 Nov 2021)

Google 'wooden wall mounted bike rack' images. They have a lot of ideas that circumvent the leverage problem.


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## Cabinetman (21 Nov 2021)

Jameshow said:


> I would run a 200mm run of ply along the wall then have your ply arms notched say 6mm into this then run another 200mm length of ply flat on the top screwed into both the arms and the wall board.
> 
> This way the ply along the top is taking the strain and serves as a useful shelf for helmets and shoes?
> 
> Cheers James


 Trouble with that though James is that you would be screwing down into the edge of the plywood.


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## Cabinetman (21 Nov 2021)

dzj said:


> Google 'wooden wall mounted bike rack' images. They have a lot of ideas that circumvent the leverage problem.


Haven’t looked yet but the obvious way is a couple of gallows brackets made from pine.


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## Ollie78 (21 Nov 2021)

What about just a box joint ?

Ollie


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## pulleyt (21 Nov 2021)

recipio said:


> I would suggest using 10 mm dowels either as a hidden joint or simply run in from the side arms as in the photo.



+1 for dowels. If I were doing this I would make it up with basic butt joints as in your photo i.e side panels butting up to the edges of the back panel. Once that joint had dried I'd then reinforce the butt joints with dowels.


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## Cabinetman (21 Nov 2021)

pulleyt said:


> +1 for dowels. If I were doing this I would make it up with basic butt joints as in your photo i.e side panels butting up to the edges of the back panel. Once that joint had dried I'd then reinforce the butt joints with dowels.


Sorry, I have to disagree, I’m confident that would tear the front face off the backboard the first time that somebody wasn’t too careful.


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## pe2dave (22 Nov 2021)

Daft idea? Ply isn't the right material for that job?


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## Jones (22 Nov 2021)

A couple of large dovetails would do it. Dovetails are designed to resist the racking force you will have . Otherwise just reinforce the join will a fillet glued and screwed in. You won't get furniture grade dovetails in ply but the mechanics will still work.


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## dephill (22 Nov 2021)

I think ply is plenty strong enough for this job, at least 18mm birch ply for the backboard, glued and maybe a couple pins till dry. Then two or three 8mm dowels inserted from the outside, possibly biased slightly towards the wall to provide a little more meat at the front. Also the length of the joined area would make a massive difference - the bracket in the picture looks to be 3 or 4 inches high. If you made it closer to six or eight the glue area and dowels would easily be sufficient.


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## dephill (22 Nov 2021)

As long as the bikes aren’t like this:


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