LumberJocks

2" dado on table saw

  • Advertise with us

« back to Safety in the Woodworking Shop forum

Forum topic by RickDel posted 04-05-2020 07:20 PM 406 views 0 times favorited 12 replies Add to Favorites Watch
View RickDel's profile

RickDel

53 posts in 641 days


04-05-2020 07:20 PM

Hello, I’m a beginner level woodworker and I want to make a torsion box out of 4” MDF. I’ll be making the lap cuts with an 8” dado blade on the TS. I know making dados and rabbets with a router is normally done with multiple passes, but is that the same with a TS and dado blade? Or do I just cut the entire 2” cut in one pass? Thanks.


12 replies so far

View WhyMe's profile

WhyMe

1309 posts in 2407 days


#1 posted 04-05-2020 07:34 PM

The widest dado I know of for a regular TS is a little over 3/4” so it take multiple passes to do 2”. Duh.. I guess you’re talking about the depth not width. Yes it’s best to make multiple passes, 2” is a lot to cut in one pass. But it will depend on which way you are cutting, along the length or through with board on thin edge.

View Bill White's profile

Bill White

5302 posts in 4806 days


#2 posted 04-05-2020 07:34 PM

I’ve never seen a dado blade set that will cut a 2” dado in one pass. Multiple passes? Yes.

-- [email protected]

View Fred Hargis's profile

Fred Hargis

6412 posts in 3339 days


#3 posted 04-05-2020 07:42 PM

I think you’re referring to the depth of the cut (that’s a question), and if true I just did that last week and cut the entire 2” in one pass. Actually, I think my web was more like 3 1/4” deep…so my cut was likely closer to 1 5/8”. I also gang cut the members, clamping them together and cut the short ones at the same time, then the long ones. The loong ones would be tricky on a TS (I used an RAS) but it could be done.

-- Our village hasn't lost it's idiot, he was elected to congress.

View RickDel's profile

RickDel

53 posts in 641 days


#4 posted 04-05-2020 07:43 PM

Yes, depth…. Thanks!

View shampeon's profile

shampeon

2167 posts in 3029 days


#5 posted 04-05-2020 07:43 PM

You’d need quite a large HP motor to spin and cut a 2” dado to full depth in one path. Certainly not the kind of saw you’d find in a home shop.

When you cut your dado, set up a stop block with an offcut of the 2” wide piece on the inward side, then make the first cut. Then remove the offcut and replace it with another scrap piece the same width as your dado stack (for example, if your dado set is 1/2” wide, a scrap piece 1/2”), and make the second cut. Remove any waste in the middle, and you’ve got a dado exactly the same width as your cross piece.

-- ian | "You can't stop what's coming. It ain't all waiting on you. That's vanity."

View tvrgeek's profile

tvrgeek

1042 posts in 2495 days


#6 posted 04-05-2020 08:27 PM

I would not try and cut more than 3/8 depth at a time.

View RickDel's profile

RickDel

53 posts in 641 days


#7 posted 04-05-2020 08:40 PM

Thanks guys…. multiple cuts. Got it!

View Lazyman's profile

Lazyman

5794 posts in 2233 days


#8 posted 04-05-2020 08:58 PM

With MDF, I would do 2 passes. I’ve done plywood with a single pass at over 2” with no problems. For best results make sure that you attach a backer board to your miter gauge or use a cross cut sled. This will support the cut on the back and prevent tear out. It also makes it easier to set a stop block so you can make multiple identical cuts, since all of the the cuts on parallel boards need to be in the same place.

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

View LeeRoyMan's profile

LeeRoyMan

1397 posts in 573 days


#9 posted 04-05-2020 10:23 PM



I think you re referring to the depth of the cut (that s a question), and if true I just did that last week and cut the entire 2” in one pass. Actually, I think my web was more like 3 1/4” deep…so my cut was likely closer to 1 5/8”. I also gang cut the members, clamping them together and cut the short ones at the same time, then the long ones. The loong ones would be tricky on a TS (I used an RAS) but it could be done.

- Fred Hargis


I agree with Fred.
I would try the first cut full height and see how it goes. If it’s touchy try a couple of passes. It’s hard to say when we have no idea what type of saw your using, or your set up of off tables and/or side tables for support.

-- I only know... what I know....

View RickDel's profile

RickDel

53 posts in 641 days


#10 posted 04-05-2020 10:35 PM

Thanks guys…. I’m going to do the multiple passes. I have a small portable Bosch 4100. It’s really no more work to do multiple passes. I mainly wanted to ask for the knowledge of what more experience guys are doing. Thanks Again.

Question Answered. Thanks

View therealSteveN's profile

therealSteveN

6228 posts in 1420 days


#11 posted 04-06-2020 05:38 AM

I agree with LeeRoy, and Fred. Try full depth. You have an 8” blade, so it would do it, and for a cross lap cut, you are going to limit width to the size of your members on the Torsion box. Most folks use 1/2” or less on the thickness of torsion box material, for weight.

I think you could cut 3/4” stuff as well, maybe just couldn’t lift the torsion box once built.

Let us know how you do.

-- Think safe, be safe

View Fred Hargis's profile

Fred Hargis

6412 posts in 3339 days


#12 posted 04-06-2020 10:42 AM

To be clear: my cuts were in plywood, and I did need a backer board on the exit side. But in terms of power, my RAS is a (true) 1.5 HP saw and it had no problem. But maybe with MDF and a your saw multiple cuts might be best. You could also do it the more conventional way: no lap joints. The cross members side-to-side would be cut to length and then toe nailed with brads and glue to the longer members….that’s how David Marks did his IIRC.

-- Our village hasn't lost it's idiot, he was elected to congress.

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com