Blade kerf with riving knife-- std vs thin ?

[Don Jeansonne]

I need to replace a standard 0.125" blade on my Grizzly 1023R that uses a rving knife. Grizzly says that the knive requires you to use a standard kerf blade as the thin kerf ones are thinner than the knife and they don't make one to match.

I really would like to use the thin kerf ( 0.0904") blades as they are more readily available, cheaper, and have other advantages. But the 1023 at 3hp can handle the 0.125" blades no problem.

My question is --- If I can adjust the riving knife correctly on the right side and let the left side of the blade be misaligned, is that a bad thing? I really never use the left side of the blade and when needed I would remove the knife. This would let me use any blade kerf.


Any suggestions?

[Chris Kennedy]

Maybe I am not envisioning this correctly, but the problem that I would see is that the riving knife would be thicker than the kerf made by a thin kerf blade, and then you are in for a world of trouble.

Chris

[Chris Fournier]

The riving knife will likely be wider than the kerf if you go the thin kerf blade route - the wood stops as soon as it reaches the splitter. You could make or modify your present splitter; careful work with a surface grinder will do it. Likely machine shop stuff unless you know someone.

Honestly though, you have a three hp saw and as you say it'll power the standard blades just fine. In my experience thin kerf blades never deliver the quality of cut that the standard blades do. I use thin kerf on my skill saw and that's it.

[Jamie Buxton]

Hunh? You're going to slide a .12"-thick riving knife through a .09"-wide kerf? It won't go.

[Howard Acheson]

Take the riving knife blade to a machine shop and have them grind it thinner. No big deal.

[Andrew Joiner]

That is why riving knives might not get used much in my opinion. You need to match blades to knives. Like blade guards, many woodworkers never use them.

[Alan Schwabacher]

That is why riving knives might not get used much in my opinion. You need to match blades to knives. Like blade guards, many woodworkers never use them.

I disagree. You need to make sure the riving knife is aligned, and not too large. But a riving knife thin enough for a thin kerf blade will be just fine for a standard kerf blade.

[glenn bradley]

a riving knife thin enough for a thin kerf blade will be just fine for a standard kerf blade.

I feel the same way. It should fit as well as possible and I would prefer one for "most" full kerf blades and one for "most TK blades but, until it gets too thin to do its job it is not super critical. I have run several splitters that did not fit like a glove yet, still did their job.

[Jim O'Dell]

Two other possibilities. One that I am thinking of with my 691 is to take the splitter with the blade guard and cut it down to a riving knife and have it ground for my one and only thin kerf blade. Another would be purchasing another riving knife from Grizzly and have it ground down for a thin kerf set up. Since the only TK blade I have is a 30 tooth Forrest WWII, and I would only use it on the 691 for ripping since it should rip better than my Infinity 50 tooth Combo Max, it will probably be cheaper for me to go ahead and get the dedicated 24 tooth ripping blade I really want. Don't know what it would cost to get the grinding done. The Infinity Ripper is only 51.90 less 10% offered to us here at SMC. Add something else I need to get above 100.00 and shipping is free. :rolleyes: Extra riving knife for the 1023 series is 11.00 plus shipping. The one for the 691 is 34.50 plus shipping. If you can get the grinding done cheap, buy the extra knife and be safe. Jim.

[David Kumm]

Riving knives are available in different thicknesses. Get a second one, inventory is good. Dave

[Ronald Blue]

I thought the purpose of the riving knife was to help control boards that have stress in them from "pinching" in on the blade causing kick back. If the knife is surface ground down thin enough for a thin kerf blade it will no longer be effective for a standard blade. Get a second knife so you can have both if you want to be able to run both blade types.

[Jim O'Dell]

David, Grizzly doesn't offer a thin kerf knife...I wish they would. (Hint hint Papa Griz!!) Seems like Powermatic does offer both for the PM2000, but I doubt that knife would fit the Grizzly saw. The other saw that is like my 691 is the Laguna model, and they don't even offer a riving knife!! Just the splitter/guard that I've thought about cutting down and grinding to a TK knife. I guess it might be worth looking at the PM knife just to see if it would work, but I'd be surprised if it did. Jim.

edit: I just looked at the parts listed on ereplacement parts dot com for the PM2000. The knife looks similar in the drawings, but who knows. Might take mine up to Woodcraft one of these days and compare. But they only showed one option in knives. So maybe I'm thinking of a different saw. Jim.

[David Kumm]

Go to Felder, Hammer, MM for riving knife. Most are made with a 12 or 13mm groove and can be used on any similar machine. I am not familiar with the Grizzly setup but check the dimensions and talk to the Euro's. I use a felder on my Knapp. Think it cost about $50. Dave

[Don Jeansonne]

I think the best bet is to get a second knife and grind it down.

Thanks

[Prashun Patel]

I'd just get a regular 1/8" kerf blade. I don't believe there's any advantage of using a thin kerf blade for a properly powered saw.

If you really want a thin kerf riving knife, I'd contact Lee Styron (maker of Sharkguard). I bet he makes one and I bet it's inexpensive.

[Alan Lightstone]

My Sawstop came with thin and regular riving knives. If they fit your saw, they could be a source also.

Is there a disadvantage / risk using a thin riving knife with a normal kerf blade?

[David Kumm]

If you rip a board far enough to clear the riving knife and stop the cut, then pinch the board to close the kerf behind the riving knife and the kerf does not bind on the back of the blade the knife is doing it's job. If the knife is too thin, theoretically the kerf could close behind it and the knife won't stop the close before the blade binds. Also dependent on the depth front to back of the knife and it's distance from the blade. Dave

[Chris Fournier]

I think that the greatest quality of the riving knife is that it prevents kickbacks when ripping against the fence, keeping the kerf open is secondary to me but even a slightly thinner riving knife (when compared to the kerf) is going to help with this too. If you have material that is really closing up and pinching the blade (heavy cuts of poplar come to mind) go to the bandsaw.

[craig greene]

Have you tried a TK blade with your current knife? I just purchased a Polar Bear hybrid and according to the manual, the knife has a range of blade widths that can be used. All my TK blades (Forrest, Freud, Ridgid) work fine with my knife.

[Charles Krieger]

Would a picture of a Powermatic 2000 riving knife with a 6" scale included help? If so I can make it happen.

[Jim O'Dell]

Yes Charles, that might help me at least. I'm sure the spacing and size of the legs will make the difference on if it will work or not. Thanks! Jim.

[Andrew Howe]

A machine shop will charge you for an hours work just to grind one down. Better to go to a micro steel supplier and order the right thickness of steel and use your existing riving knife as a template.

[Charles Krieger]

195805 Here is the picture made by scanning the knife so there should be no little or no distortion of the shape.

[Jeff Books]

Try Lee Styron of Sharkguard. He has riving knives at multiple thicknesses and reasonably priced. I don't know if he has one for Grizzly yet, but suspect he would be interested.