Types of wood joints

The rebated joint should prove to be the most useful joint to use. The added area for gluing is only secondary to the most important part. When you rebate a panel you create a shoulder, and that is the key to accurate assembly. All ASS cabs were made working from inside dimensions. The importance of this is that when you buy 18mm ply, sometimes it can be 17mm or up to 19mm. When you work from a shoulder size, everything remains constant and you throw the tolerance to the outside.
The same principal applies to grooves. It must be very tempting to machine an 18mm groove and slide the panel in, but there is no control over size variations. So it is better to machine, for instance a 9 mm groove, and make a tongue on each side creating a shoulder size. It then doesn't matter if your groove goes deeper than it should because the shoulder that you create keeps everything constant. This is very important when assembling horn cabs. I hope this clear and helpful.

If your joints are spot on then pva is great, if they are not so spot on then theres loads of filler expanding wood glue available. It is always best to get your joints 100% square.

Tony.A.S.S. wrote: The rebated joint should prove to be the most useful joint to use. The added area for gluing is only secondary to the most important part. When you rebate a panel you create a shoulder, and that is the key to accurate assembly. All ASS cabs were made working from inside dimensions. The importance of this is that when you buy 18mm ply, sometimes it can be 17mm or up to 19mm. When you work from a shoulder size, everything remains constant and you throw the tolerance to the outside.
The same principal applies to grooves. It must be very tempting to machine an 18mm groove and slide the panel in, but there is no control over size variations. So it is better to machine, for instance a 9 mm groove, and make a tongue on each side creating a shoulder size. It then doesn't matter if your groove goes deeper than it should because the shoulder that you create keeps everything constant. This is very important when assembling horn cabs. I hope this clear and helpful.

What would the rebated panels look like?
Thanks for your help.

What would the rebated panels look like?
Thanks for your help.

Well, I thought Tony was talking about cutting a grove on both panels. 9 mm on each panel to form a shoulder.

DJ, Just to clarify. The grooves I referred to were when you are doing internal grooves for horn loading. The shoulder size becomes the internal dimension when placing all the horizontal panels.
For instance, in a scoop bin, if you imagine the horn path and then the panels that make it. Some people butt joint after drawing the shape on the sides. Others machine a groove to suite the thickness of the ply or MDF that they are using. My method was or is to machine a 9mm groove in the side panel and then machine a rebate on either side of the internal ply panel to make a tongue that will fit the groove. Usually made slightly shorter than the depth of the groove so that there are no foul ups in the bottom of the groove. The tongue slides into the groove and when fixed both sides the internal dimension is maintained by the shoulder size. I hope this is a clear explanation.

Missing word.Edited by: Tony.A.S.S.

Sounds like a good reason to have a router table, would take ages to do both sides and both ends of each panel with a hand-held router!

Ok thanks Tony, i think I understand it.
Sounds really strong. If you ever find any pictures of it post it for us.
Thanks again for that tip on that glue. (the stuff that you coat paper cones with)
thanks again for your knowledge

looks like a pair of shoulders

chaudio wrote: Sounds like a good reason to have a router table, would take ages to do both sides and both ends of each panel with a hand-held router!

you do it with a spindle moulder Chris not a router

its done with one run through