Full kerf or thin kerf

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I have used a think kerf CMT General in my original contractor saw for years, then when I got my cabinet saw, it's been with that for about two years and I'm very happy with it. My brother is just putting together his shop and he is choosing a Griz 1023SL TS and I was going to get him a Forrest Woodworker II as a shop warming present. The problem is that I can't decide between full or thin kerf. Why would I ever want to use more kerf than necessary - there must be a reason, but it escapes me. Thanks for any input.
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DJ
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The theory I heard is that the thin kerf would be more likely to experience vibration issues, since it would be marginally more flexible. So if your saw can drive a full kerf blade, that seemed to be the most advisable.
Having never compared directly, I don't know how much of an issue that actually is.
Clint

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DJ wrote:

The full kerf blade is less prone to flex.
It also offers a little more resistance before bending when you tilt the blade with the zero clearance insert still in the saw.
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Jack Novak
Buffalo, NY - USA
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Been there done that
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Think kerf helps an under powered saw cut faster.
From there the thin kerf is a disadvantage as it flexes and does not produce as flat of a cut as a regular kerf blade. You may not realize the flex until you switch to a premium quality regular kerf blade. In particular you see the difference when cutting miters and compound miters.
Get him the regular kerf blade. I used thin kerf blades for years until I discovered Premium regular kerf blades.
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On longer ripping jobs the TK blades are more likely to heat up and wobble.
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DJ wrote:

I'm betting that most folks here work with stock that's considerably less than an inch and a half thick - David Eisen being the exception (see his table legs - out of ash as I recall). Just finding stock thicker than 3/4" can be an adventure. And no one works with ply thicker than 3/4". So for a table saw, and the stuff you typically do with it, blade flexing isn't an issue - assuming the blade and fence are set parallel to the miter slot - a BIG assumption in some shops. So a thin kerf blade works just fine - for me. In fact, I leave a 7 1/4" blade on my Robland - Freud and CMT make some nice carbide tipped blades for circular saws that work just fine. Why spin a 10" full kerf blade when it isn't necessary. And kickback, if it should happen, is a LOT less dramatic with a think kerf than it is with a full kerf.
No on a miter saw, compound miter saw, sliding miter saw or sliding compound miter saw - you NEED a thicker blade - and a 12" will give you more cutting capacity - both in height and width. But with the thicker blade and larger diameter comes the opportunity for Mach 10 UFOs. There are always trade offs in life - the trick is to minimize the likelyhood that one of those trade offs doesn't damage any body parts you really need.
My vote - unless it's for a miter saw, go with a thin kerf.
And BTW, you can get three or four thin kerf, carbide toothed 7 1/4" blades for the price of one really good full kerf 10". At the first hint of dulling I'll replace a blade, putting the "less than perfect one" on the carpenter's circular saw. I still haven't sent my original WWII back for sharpening and it's replacement WWII wasn't as sharp as it had been - which is how the 7 1/4" thin kerf discovery was made.
charlie b
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I talked to the Forrest demo rep after a demo at a local shop and he suggested the thin kerf with a 5" stabilizer for my Delta hybrid TS. I am not sure if I told him I just had a hybrid saw, but he felt that was the way to go. So far I have been very pleased with how it cuts. Do most people use stabilizers?
-Steve
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They should if using thin kerf blades.
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5" stabilizer will reduce your max depth of cut from 3" to 2.5"
I am

I have one and really only use it as a spacer.... but then again, I prefer thick kerf.
-Steve
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And assuming that the stock you are ripping is perfectly straight. I don't know about you but I would bet 99% of the wood that I rip is not absolutely straight.
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Leon wrote:

Ah - stock prep - the elephant in the room nobody wants to talk about.
If you don't have one straight edge, square to the top and bottom of the stock and the top and bottom parallel - preferably with squared off ends - you're starting off with one foot in the hole - and digging. The hole you'll find yourself in eventually - assuming you make it to glue up without one or more trips to the emergency room worse case, or to the house for some ice, or maybe just a band aide, will make it crystal clear why the old maxim - "You can't make rectangles out of trapezoidal parts!" warrants taking to heart. (Now I know there's someone out there who's heading for Auto CAD to come up with a way to disprove the maxim and post the solution here, or to a.b.p.w. or the url to a page or two with the solution.) For some reason, which seems to defy the randomness of nature, wood working errors always seem to accumulate rather than being self cancelling /compensating.
Then we come to "perfectly straight" and how close is "close enough"? If the edge against the fence isn't "close enough" to straight then a regular kerf or thin kerf is the least of your problems. If it's off by enough to make the thickness of the blade an issue - or the need for a stabilizer, why not just hit the high spot(s) with a hand plane for a pass or two in that /those areas and then make the rip cut?
Inquiring minds want to know.
charlie b
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Think S2S lumber that is straight on one edge and has a curve on the other side. Basically, you have just run the piece through the jointer to straighten the fence side of the board. Now you have a curve on the side that you are going to correctly straighten on the TS. For maximum yield your blade will likely have wood on both sides as well as only on the right side, as the narrow part of the board passes the blade. If the blade is exiting and or entering or reentering wide and narrow spots on the board it is going to have a side force applied as the left side of the blade appears and reappears. Regular kerf is affected less in this situation.
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I remember reading once that one of the main reasons to use a thin kerf blade was when one was cutting really expensive wood. Don't know how true that statement was/is, but it sounds logical to me.
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Makes sense if you do the numbers.
Let's say a board is 5 1/4" wide. You need to cut two 2" pieces from it. 2" + 2" + 1/8" kerf + 1/8" kerf will leave a scrap of 1/2". If you use a thin kerf blade you save 1/16" and have a 5/16" scrap piece and the difference can be put towards your 401k or the kid's college fund.
I guess it can make serious sense in a production shop taking very wide boards to very narrow ones.
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Actually, I was thinking more along the lines of use with cabinet grade plywood. That stuff can get pretty expensive. Last time I bought some was oak veneered plywood some twelve years ago and it was something like $140 a sheet (CA) even back then. Getting into some of the exotic stuff could get really expensive. I'm afraid to look and see what it is now.
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wrote in message

Basically, a majority of the time a thin kerf blade saves enough wood to insure that the scrap you throw away is a little larger.
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I may have missed it, but so far I haven't seen any mention my favorite reason for a regular kerf blade: 1/8" is SO much easier to work with than 7/32!
YMMV :)
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Larry Wasserman Baltimore, Maryland
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7/32"? That's almost a quarter of an inch. Never seen any blades that wide, at least not in the home setting.
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OOPS! Sorry. Of coursce I meant 3/32! (Told you 1/8 is easier to work with...)
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Larry Wasserman Baltimore, Maryland
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