joining plywood

[Barry Keippel]

Hello I'm a newbee at joining with a router. I want to build a cabinet (sides, bottom and top) out of 3/4 inch plywood. I would like to use my tongue and groove bits. No problem cutting the tongue on the edge of one sheet, but what's the best way to cut the groove on the flat side of the other board. Do you hold the router sideways and then place the plate against the edge and route the groove along the flat side? My bit doesn't fit into my router table, the hole isn't big enough for the bit to pass through. I have no rabbet bit that big. Barry

[Lew Hodgett]

I wouldn't go there for several reasons.

1) Tough to get a decent T/G joint in plywood since voids appearing just where you don't need them are inevitable. 2) Trying to cut a groove in a piece of 3/4" wide any thing is just plain dangerous.

A table saw, a fence and some feather boards will allow you to do the job more safely, but again, not plywood.

If you truly need to join plywood sheets, take a look at the "Scarfer" available from the Gougeon Bros. Do a google for their web site.

HTH

[Preston Andreas]

You would be much better off using rabbets and dadoes for plywood joinery, especially for cabinets.

Preston

[bob]

How about a slot cutter? I thought that's what slot cutters were for - grooves for tongues.

Bob

[B a r r y B u r k e J r .]

Not with a slot cutter in a router table or with a good edge guide.

Do both sides of the joint with the slot cutter. Use a thin piece of wood or hardboard as a "spline" to join them.

Before the slots are cut, the edge must be straight and 90 degrees to the faces.

Barry

[Chip]

Dare I be bold enough to suggest a pocket hole?

[Bay Area Dave]

and if all the other tips don't help, perhaps you could use biscuits...

dave

Barry Keippel wrote:

[Bay Area Dave]

oops! never mind. for a cabinet you should be using dados; not biscuits. shame on me for speed reading again.

dave

Bay Area Dave wrote:

[Kevin Johnson]

Dave,

Educate me, new to woodwork>oops! never mind. for a cabinet you should be using dados; not

[Swingman]

Not to say that biscuits won't work, however, rabbet/dado joinery for case sides in plywood will give you a greater mechanical advantage, more glue area, less or no clamping time and therefore quicker use of the the component, and a carcase that is much easier to 'square up' than one joined with biscuits and glue.

"Square" is the holy grail of cabinet making as all future operations depend upon it, such as applying face frames, and fitting drawers and doors.

[Kevin Johnson]

Dave,

Educate me, new to woorwork>oops! never mind. for a cabinet you should be using dados; not

[BP01]

Biscuits work just fine there is little advantage to rebating unless your using relatively thick material but for 18 - 22mm they`re more than sufficient

[Mike Hide]

I have been using splines for years they are so simple to use a 1/4" cutter with a bearing and a router is all you need .set it up to cut in the center of one sheet and all is done insert the sline and glue it up.........mjh