Thin Kerf vs. not

[John Hulett]

As I, like several others - I'm sure, was preparing to cut the material for my gift cutting boards, I thought I'd use my thin kerf rip blade (cheapo Freud Diablo) so as to minimize waste lost by the cut (since I'm cutting 1/8th inch strips of Walnut and Purple Heart to begin with), as opposed to the Amana combo blade I use 90% of the time. The Amana give me a cut I'm happy with, but again, waste was a concern. Though the Amana gives me a decent cut, I've eyeballed the WWII, as well as the Chopmaster for my CMS.

I got to thinking about if I actually was to get a WWII, would think kerf be the way to go? Obviously, TK is beneficial in the situation I'm working with today, but generally when would one not want to use TK?

- John

[Jim Becker]

The WW-II should NOT be used on a CMS or SCMS. It's a table saw blade with a positive hook angle. You need a blade designed with a negative hook angle for safe cutting on those tools.

I personally don't prefer TK blades. They are fine on a low-powered table saw, but outside of that, I like a "standard" kerf blade. That said, many CMS/SCMS blades are TK or at least a little narrower than the typical 1/8" wide table saw blade. But a heavier blade flexes less and will generally cut cleaner longer, IMHO.

[John Hulett]

Let me clarify - I was considering the Chopmaster for my CMS, and the WWII for the TS. Relative to the WWII, when would TK not be preferable? It seems the answer is when you have a decently powered TS.

[glenn bradley]

I run TK blades 99.99% of the time with no problem (Freud, Lietz, WWII). The savings in material is not that great (+/- 1/32"). Chopmaster for the CMS, WWII for the TS.

[Glen Blanchard]

One thing to consider is that most splitters and/or riving knives (I'm having to get used to referring to riving knives nowadays) are not compatible with TK blades as they are thicker than the blade itself.

[Art Mann]

Maybe I'm just not discriminating enough, but when I went to a thin kerf blade, I couldn't tell any difference in cut quality. I think the brand and model of blade makes more difference. It made my slightly underpowered saw perform much better. OTOH, the thin kerf carbide is pretty small and won't take too many sharpenings before it is worn out.

[scott spencer]

Many of the more respected manufacturers suggest using a TK on a saw of < 3hp, like a contractor saw or hybrid. Many will attest to the fact that most good contractor saws or hybrids will cut fine with a full kerf, but the feedrate will be faster with the comparable TK version and the motor will strain less....just a matter of physics there. If you're saw is a full 3-5hp cab saw, you shouldn't need a TK....the material savings aspect is minimal. You will also see less benefit on a CMS, b/c crosscuts are easier than rips. Any deflection issues would be more exxaggerated with a 12" blade than a 10" or smaller, so I wouldn't suggest one in a 12" either.

I've used nearly 20 TK's and probably 10 full kerf blades on my contractor saw and hybrid, and have not noticed a difference in cut quality between the TK's and full kerfs. I also have not had even a trace of deflection, but have definitely noticed the increase in feedrate with the TK's. As long as you stick with the high quality names, and the splitter is the correct width, the TK's should serve a hobbyist fine.

[John Huber]

I was resawing 3" tall x 30" long walnut on my table saw using my thin kerf Woodworker II blade with appropriate Micro Jig Splitter. The blade was perfectly parallel to the vacuum fence. Examining the resawn boards afterwards showed the cut was on target at the start, but the top of the blade drifted away from the fence further along the cut. By the end, the top was almost 1/16" farther from the fence than the bottom. There was no scorching or burning of the wood.

It seemed to me that heat from resawing was causing the think kerf blade to warp. So I bought a standard kerf Woodworker II and appropriate Micro Jig Splitter. Now when resawing tall hardwood on my table saw, the cut is nearly perfect (less than 1/64") -- top to bottom and end to end.

[scott spencer]

I was resawing 3" tall x 30" long walnut on my table saw using my thin kerf Woodworker II blade with appropriate Micro Jig Splitter. The blade was perfectly parallel to the vacuum fence. Examining the resawn boards afterwards showed the cut was on target at the start, but the top of the blade drifted away from the fence further along the cut. By the end, the top was almost 1/16" farther from the fence than the bottom. There was no scorching or burning of the wood.

It seemed to me that heat from resawing was causing the think kerf blade to warp. So I bought a standard kerf Woodworker II and appropriate Micro Jig Splitter. Now when resawing tall hardwood on my table saw, the cut is nearly perfect (less than 1/64") -- top to bottom and end to end.

John- 3" thick stock would be better cut by a 24T ripping blade regardless of kerf.




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[John Hulett]

One thing to consider is that most splitters and/or riving knives (I'm having to get used to referring to riving knives nowadays) are not compatible with TK blades as they are thicker than the blade itself.

That was my biggest concern with the change; I have a MJ Splitter for standard kerf, but not for the TK. After using the splitter for some time now, I was really nervous about not having one while using the TK. It worked out fine in the end, but I would have felt much more comfortable with the splitter in place.

[Charles McCracken]

John- 3" thick stock would be better cut by a 24T ripping blade regardless of kerf.




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I agree. In fact I would suggest less than 20T for 3" rip. 30 to 40T is WAY too many to clear the chips effectively.

[glenn bradley]

I run the TK splitter. $14, no big deal. Obviously you'll have different ZCI's for your TK blades and the hole pattern on the TK splitter is different than the full kerf version for just that reason. When I make ZCI's, I just make a half dozen or so. As long as I'm already set up, why not? Then I finish off the saw cut and mount the splitter the first time I use it. I mark the bottom with a felt pen as to the blade the ZCI is for at this time as well (old-timer's disease prevention, eh?). If your MJ splitter jig-board is already made up you can drill for the splitter in a matter of minutes and the ZCI is ready for next time.