Woodworking Talk banner

Was This an Acceptable Dado Technique??

5K views 6 replies 4 participants last post by  rrich 
#1 ·
I was doing dado cuts with a stacked dado tonight and was wondering as I was doing it whether it was a safe practice. So I thought I'd ask you pros.

I'm making an oak wall shelf with three 3/4" horizontal shelves and two 1/2"vertical dividers (aside from the outside 'box'). These all intersect so I need to slot each shelf and divider halfway through so they interlock. The shelves each got two slots and the dividers each got three.

So to cut the slots, I put the shelves on edge on the table saw against an Incra miter gauge and cranked the 8" dado head up to almost 2" to do the cuts. I used a stop block on the fence (set back, of course) to cut the three shelves and did the dividers by clamping them together and then clamping the pair to the miter gauge. I made one full depth cut for each slot.

I was wondering if there was any problem with this other than having the spinning dado head exposed almost 2" above the table. All went well, no splintering to speak of (I fed slowly) and everything lines up great, to my amazement. The whole process made me kind of nervous, though.

Bill
 
See less See more
#2 ·
nervous...yep

I issue I see with the dado head that far up is any lateral movment of the workpiece may cause a jamb and a kickback since there is a lot of leverage against the stack.
By securely hold the work from moving like you did with a clamp on the miter gauge then it would probably feel a bit better. The width of the cutter that high up just "seems" more intimidating than a narrow blade.... and it probably is. :laughing:
I can't come up with a different method other than a double kerf and wasting out the middle with either more kerfs or a chisel.
Sounds like it worked OK for you, but when you look back it may not have been as safe as you would have liked. :blink: bill
 
#3 ·
It's a good thing you completed the procedures without a problem. I would have done it differently. I would have used a router for all the dadoes, not a stacked set.

For ends of a cabinet they can be edged clamped so the dadoes are lined up perfectly. For dividers, they get dadoed from both sides to accept shelves. Structurally IMO that provides a much better method than interlocking. The edges of the shelves are hidden in the dado.

I find that router use can be simpler, and more accurate, and safer. I prefer to see what I'm doing, which is working with the stock face up. I feel I get cleaner cuts. For handheld use, I use my shopmade jig, which you've likely seen by now (if not, I'll provide a link). Some machining I'll do on the router table, depending on the size and what's needed.






.
 
#4 ·
I did all the dado's for the ends of the shelves with a router, then did the tenons on the table saw. I just didn't see a way to make the shelves interlock without deep dado's (unless I did chisel work) even though I was kind of leery of the way I did it.

I could have made the vertical dividers separate pieces but I figured that would add to the chances of a mistake resulting in a crooked looking divider.

Anyway, I'm glad that little chore is done! I still have to rout some dados in the top and bottom of the shelf assembly for the vertical divider's ends. I'll have to post some pics so you have a better idea of what I was doing.

Bill
 
#5 ·
something like this?

crossed edge half lap --- A crossed half lap joint where the two mating pieces are presented to each other edge to edge instead of face to face. Examples:

 
#7 ·
I think that I would have cut dados in the shelves and then fit the vertical pieces into the dados. If the vertical supports were glued into the dados, the shelves would be the equivalent of solid wood. As the shelves are now, the interlocking feature has slightly weakened the shelves.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top