Thread: Box Joints - Router Table or Table Saw

Hi Mike. I bought a CMT Dado set for my table saw (contractor style with 5/8" arbor) and I am a little disappointed with the quality of the cut. The seat of the cut isn't perfectly flat but has a little chip. Annoying. But it's great for other joinery - tenons, bridle cuts and rebates. My saw has no trouble driving blades but arbor length doesn't allow for all of them to be used. Hope this helps!

Perhaps a better alternative to a dado blade is a box joint blade.
although these are advertised as only cutting two sizes of joint, judicious use of shims allows you to cut wider box joints -- out to almost 8 mm for a nominal 1/4" blade.

I bought the iBox and find it very time consuming and fiddly to set up, so i don't use it as much as i should. I only do box joins and set all fingers and slots at 10mm so all my box heights are in 10mm increments.

In hindsight i should have just bought a dado set and made my own jig

I have none of the above but I do have access to a router table finger joint jig and I believe the most expensive part was the spiral head cutter at about $68. Actually there are 3 different cutters 5/16, 1/2, 3/8

either way you are still going to have to make a jig/sled for the table saw or the router so I would say go the router option.

here is a pic of the result from the finger joint jig I use, and probably would be totally invisible if not for the type of timber and it's perpensity for tear out. Next time I use this I will put a price of sacrificial 3mm msg behind it to stop tearout.

IMG_4650.jpg
You will have to look very closely for the joins, but this is 1 piece, finger jointed 4 times for the box pictured below.
IMG_4717.jpg

Best of luck with with your decision.

Thanks for the replies. Food for thought.
Cheers
Mike

William Ng has a video on youtube showing a sled that will cost literally nothing to make.

I use the tablesaw, an Incra iBox and Forrest box dado blade (2 pieces) also from Incra. Perfect cuts... absolutely perfect. Love it.

If I haven't used the iBox for a while I do need to do a quick revision on its operation, but it really isn't too hard.

I've also an under table router, incra fence and a zillion cutters, but I only use that for dovetails. It can, however, be used to do box joints. My trial of it to do so produced an excellent result. The only negative is the bit must be absolutely perfectly sized, whereas with the iBox it may be adjusted to any arbitrary width.

Whether cutting dovetails or finger/box joints on the router table you should always back up the stock with a sacrificial piece. This is good practice regardless of the cutter you're using. It only takes the most minor of catches to tear out the edge of your cut ruining the finish. It's so easy to avoid you'll be kicking yourself if it happens to you.