# Problem wit a board binding during ripping



## JFPNCM (Dec 13, 2009)

I successfully ripped a series of 5/4" x 6" dry cedar slabs each about 30” long (cut from multiple 6 footers) into 2” strips on my TS when I encountered 1 slab that bound the blade. The initial 3-4” cut like butter and then the blade slowed and a significant amount of pressure built against the forward movement of the slab. I stopped the blade immediately. In order to remove the board I had to release the fence and add a wedge behind the blade to spread the cut. 

The blade was damn sharp; the fence true to the blade and the fence side of the board had been passed through a jointer resulting in a good edge and the blade was running about 1/2" above to allow ample clearance for the gullets. The cedar was also dry. 

When I sat the slab down on the TS I noticed a very subtle side to side rocking motion which went away when the board was turned over. A quick check with a square showed a very minor cupping in the board which was not otherwise noticeable. I am assuming on that basis that once the rip had started the slab was free to torque and closed in on the blade even though the ripped end was well past the MicroJig splitters. 

A 2nd slab from the same board created the same result. The next slabs from 2 other boards cut like butter. 

Open to any and all thoughts on this one.


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## kp91 (Sep 10, 2004)

Twist or internal tension. You can change the mj splitter around to give a little mora push to one side.


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## Cherryville Chuck (Sep 28, 2010)

We call that timber bound. I once saw a hemlock log close up on a 52" diameter head saw that was being driven by an old D8 caterpillar engine. Before the sawyer could stop the saw tore the log loose out from under the carriage dogs and tossed it back onto the feed deck. This was a green hemlock log about 20" in diameter and 8' long. It's caused by internal tension that makes the wood want to close up on the cut. You can back it out of the cut and start again and it could take 8-10 passes before you can get through it but the piece will be so off sized and possibly crooked that you may not be able to use it anyway. This is actually a potentially very dangerous situation because when the cut closes on the back of the blade it can be lifted and thrown with great force.


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## Rube (Feb 8, 2005)

Do you have a riving knife/splitter installed? If not !!???


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## tooler2 (Aug 11, 2012)

We call it reaction wood. It is a good time to use a short fence but bear in mind the wood may not be suitable for furniture in larger pieces.
Rob


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## DonkeyHody (Jan 22, 2015)

The board has internal stresses that are partially relieved when you cut part way through the length. Sometimes these stresses are strong enough to pinch the blade even with a splitter in place. The internal stresses could have been present all along if the tree was leaning, or had a lot more weight on one side. Or, it could have resulted from improper curing. The pieces that come from such a board are quite likely to continue to move as the internal forces equalize after sawing. Unless the pieces are small and easily restrained, I'd not use them.


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## JFPNCM (Dec 13, 2009)

Appreciate all the comments. My situation was frightening enough I would not want to be around the situation you described Chuck. That might call for new underwear. 

Yes Rob there was an MJ splinter in place. 

I eventually cut those slabs into 5" blocks and used them as corner pieces in a rough planter for the side yard.


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## Cherryville Chuck (Sep 28, 2010)

Jon it was a cousin who was doing the sawing and he is also a big guy. The two of us couldn't pick that log up and yet it got tossed at least 8' through the air back onto the feed deck. We were cutting railroad ties and the log started out large enough to get two #1 ties out of (7" x 9" x 8') and when he finally managed to nibble his way through the log it only made two #2s (6" x 8" x 8'). It definitely got our attention when it happened. We knew something wasn't right when we heard the change in pitch of the saw and that big D8 engine bog right down.

I've since had it happen on my table saw a couple of times, particularly with some #3 red oak I bought. The one good thing that came out of the sawmill experience is that I'm able to recognize when it starts happening on my table saw.


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## TwoSkies57 (Feb 23, 2009)

Cherryville Chuck said:


> Jon it was a cousin who was doing the sawing and he is also a big guy. The two of us couldn't pick that log up and yet it got tossed at least 8' through the air back onto the feed deck. We were cutting railroad ties and the log started out large enough to get two #1 ties out of (7" x 9" x 8') and when he finally managed to nibble his way through the log it only made two #2s (6" x 8" x 8'). It definitely got our attention when it happened. We knew something wasn't right when we heard the change in pitch of the saw and that big D8 engine bog right down.


Now THAT woulda been one helluva RUSH!!!!


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## TenGees (Sep 12, 2012)

I had this ripping a 2x4... it closed the 1/8" kerf after about 12" into the cut. I never expected that much stress to be in a board, especially since it had been in the shop for ages. You'd think the tension would give out after a while but surprise, surprise.


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## Cherryville Chuck (Sep 28, 2010)

The wood that I've had do it to me on the table saw was aged a few years too. It's a possibility that you need to keep in the back of your mind. The safest thing to do if it happens is to cut the power to the saw and then lift the board off once it's stopped.


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