Ripping 8/4 walnut, almost got nasty

[Dan Mitchell]

Earlier, I was ripping a piece of 8/4 walnut on my PM2000, with a brand new WWII blade. Piece was about 24" x 8", and I was ripping off a piece about 2 1/4" wide, with the wide portion next to the fence, of course. Using a magnetic feather board & all the saw's guards. When the open end of the cut was about 2" from the riving knife, resistance began to increase considerably, accompanied by the smell of burning wood. The 3HP motor actually began to slow, which has never happened to me before with this saw. After turning off the saw, it took quite a bit of pulling to get the cut piece off the blade, which during the cut was raised so the gullets were about 1" above the top of the piece. I had a good grip in the piece, which never felt as though it was lifting off the table, but it still shook me up a bit, and I'm glad I had all the safety bits in place. I fed the piece through again without trouble, re-cutting the narrowed kerf past the knot. Here's a pic of the cut knot & resulting burn marks.

[Josiah Bartlett]

I have quite a bit of walnut that I harvested from urban trees. The grain is mostly straight but it can get really gnarly and funky, and the saw blade starts to do funny things when you relieve the internal stresses. I take it very slow when I cut, and I prefer to do anything with wavy grain that is more than 5/4 on the bandsaw instead.

You will also find that sometimes walnut is hard on your tools. It machines nicely but it tends to dull blades, especially chisels and turning tools.

[harry strasil]

When I get a piece like that, I cut half way thru from one side, turn it over and do the other half.

[george wilson]

I never cut through on 1 cut on thick stock.

[Steve Clardy]

I keep a door shim handy nearby on the extension table.

Resistance starts, I grab it and jam it into the kerf.

[Faust M. Ruggiero]

That's why I rough rip thick stock on the band saw. Besides, burning walnut gives me a heartburn. So does hot chili but the taste of the chili is worth it.

fmr

[Mike Cruz]

Nothing like the smell of walnut...ahhhhhhhhh. Can't think of a better smelling wood.

[Peter Quinn]

Yup. walnut can definitely have some tension. Mostly around knots and funky crotch grain, but sometimes where you might not expect it. I keep both hands on the wheel and my eyes open with that species. I haven't had a piece stop my saw yet but I have definitely experienced a little burning. Funny how that second pass always goes smoother.

[Walter Plummer]

For thick stock like that we use a 12 tooth rip blade that has a sizable saw kerf and it does the job well. It does leave a rough edge though.

[Dan Mitchell]

Thanks for the replies. This is the 1st time I've worked walnut, and only the 2nd time I've worked 8/4 stock, the previous experience being hard maple. Just to clarify, for those who suggested cutting half way through 1st, I'm assuming you mean raise the blade to 1/2 the thickness of the piece (in the case of 8/4, raise it 1"), do the cut, then raise the blade to the usual height for a complete cut, correct? Also, are these precautions as critical for crosscuts, or slightly less so? The piece I started with was 96" x 8" x 2", and I crosscut 2 24" lengths on my SCMS without incident. Maybe just lucky :D

I do have a bandsaw, but I sure like the nice finish the WWII gives.

Thanks again.

[Josiah Bartlett]

I've never had a problem with the kerf closing up on crosscuts. You have to be extra careful with thin kerf rip blades... like the Freud is only intended for 1" thick or less stock, and dense wood really can tax the blade. A lower tooth per inch blade with a wider kerf is a safer way to rip thick stock if you don't want to do it on the bandsaw.

[Paul Ryan]

I keep a door shim handy nearby on the extension table.

Resistance starts, I grab it and jam it into the kerf.

I do the same thing. Door shims work great, I run into that problem alot ripping 2x4's and 2x6's the tension in those boards is really something. I have had the tension grab the blade on an older saw with out any splitter on it and never had a problem though. The kerf closed up so tight the motor couldn't kickback the board. That is when I learned the door shim trick. Since then I never cut anything with out a splitter if I can help it.

[george wilson]

Yes,I cut,say,2" wood 1 inch at a time. Just what I always have done to avoid wood closing on the blade. I'm not in a production situation.

[Dan Mitchell]

I've ripped a fair amount of framing lumber with this saw, since I had a ton of it in all widths & used it initially as cheap wood to "practice on". What's interesting is the PM2000 has not just a splitter but a riving knife, which of course is only about .25" from the blade, & the wood began to firmly grip the blade before to cut had even made it that far. I see about the door shim, but since the trouble happened so early in the cut, it wouldn't have been possible to use, plus I wouldn't do such a cut without the guard in place anyway, which pretty much rules out the shim.

Thanks again for the replies.

[Paul Ryan]

Dan,

I have had to use the door shim on my saws that have rivings knifes too. The door shim helps open it up enough to be able to finish the cut. Sometimes the tension is so great the board grips the riving knife so tight you still have a hell of a time pushing it through. Usually the wood isn't worth a dam once it is cut because you released so much tension. But for some projects when i just needed 2x2's it was worth it.