cutting groove in 2X2 with table saw

I need to cut approx 3/16" wide and 1/5" deep grooves in 2x2" IPE 8' posts, down the entire length and need advice using a table saw to do this. Is it possible/advisable to get the 3/16" width groove with a thinner width saw blade by doing multiple passes? Or, should I use as thick as possible saw blade and try to do it in one pass? The thickest saw blade i've been able to find is 1/8th thick......but was told the cut is wider than the actual of the blade......so a 1/8th width blade may actually get close to a 3/16th kerf.

 

That's the sort of thing you would use a dado blade for. I would probably use an adjustable wobble dado blade. You want to make this cut in one pass.

 

Get two identical blades and install them with washer(s) between to achieve desired width of cut. Have done this several times over the years until I got a wobble head dado.
Good luck!

RR

 

Just set your fence off center by 1/32" to either side, make first cut flip post 180 degrees and make second cut!

You will need to do some tests cuts to get proper settings!

 

I don't have a dado blade and have done as Marq described multiple times.

 

Another vote for offsetting the fence. Quicker and easier than breaking out a dado blade.

 

There's a guy on youtube, Jimmy DiResta, who shows woodworking techniques, tips, and tricks. You might watch a table saw video or two- he's a clever guy.

A table saw will cut a channel with 90* corners- is that the desired result?

 

It looks like offsetting the saw fence is a good way to go. 90 degree cuts is what I want. Is offsetting the fence a simple matter? I'm not the one who will be doing the cutting, just trying to be informed about the best, easiest way to do it - with the least likelihood of screwing up.

 

What I do is set the fence to cut one side of the dado and then once that side has been cut, turn the wood around and cut the other side. With your narrow dado cut that should be all you need to do. On wider ones I've used a chisel to finish cleaning out the groove.

 

A dado blade is probably the "right" way to do it, but, even though I have dado blades, offsetting the fence and making two passes is the way I have typically done cuts like this. As far as what needs to happen, the stock has to be on the same plane as the table, meaning that you want a steady hand on the feed side as well as outfeed support, and at a minimum you want a horizontal feather board holding the stock tight to the fence, and personally I would use a vertical one to hole it tight to the table. Gravity obviously is going to hold it down, but that doesn't mean that it can't ride up at some point which would result in less depth of cut.

 

Hopefully this cut doesn't have to be a perfect finish cut, because you wont get a perfect cut doing it that way. (Moving the fence and making 2 rips)

Ipe is probably the hardest wood you will ever cut. Because of that you will encounter a problem that non carpenters don't understand. Since the wood is so hard and since your cut is 3/16... and close to the blade width, when making the 2nd rip cut, your blade will likely naturally want to bend into the first kerf cut, making the total width of your 2 cuts irregular. A sharp blade and pushing very slowly will result in the best possible outcome.

But if you wanted to err, you would be wise to err by making it wider than needed... say 1/4". Because then your 2 cuts would be far enough apart that you wont have the bending blade problem.

Of course you will also have user error, where you didnt keep the board tight against the fence while you are ripping it. If you have a feather board or two on your table saw that would help. Clamping a guide stop on the fence above the board will also help you keep your depth consistent. Ipe is so hard you will have trouble keeping it tight on the table as you rip... it will want to ride up over the blade if you dont. (Making the depth of cut inconsistent.)

This isn't like cutting pine.