OK - How common is reaction wood? Am I just really unlucky?

[Matt Armstrong]

It seems EVERYTHING I cut recently has a tendency to pinch the blade / splitter to the point where i can't even push it forward anymore. I was cutting some cedar (which I thought was a softwood so it wouldn't have the same tendencies to react like hardwoods) and it pinched the blade so bad I couldn't even dislodge the board from the blade and splitter without the use of a hammer. This had happened with some 8/4 maple earlier in the months, now the cedar, and just now I was cutting some 4/4 black walnut and the stuff pinched so hard that it literally grabbed and ripped out my microjig splitter. Does this happen a lot? I thought it was relatively rare, but I'm seeing it with everything I cut... :(

[John Loftis]

At the risk of stating the obvious, are you sure your rip fence is truly parallel to the blade? Seems like the likely culprit.

[Jeff Duncan]

Something is a bit strange here, I've run into some pretty bad pieces over the years, but never had anything pinch so bad it stuck:confused:

And I mean even having 8/4 maple bind up on me and still got it through the blade. Is this wood you air dried yourself possibly? Or is there something else you forgot to add that might explain this reaction????

JeffD

[Steve Mellott]

Matt:

This is not a common occurrence with either hardwood or softwood. My guess is that something is seriously out of alignment and needs to be fixed before the saw is used again. If you have to pound the board out with a hammer, this is a disaster waiting to happen.

Steve

[Cliff Polubinsky]

Matt,

Clamp a board to your fence that ends just before the blade so that there will be a space between the blade and the fence when and after the board is ripped. Then rip one of the boards you had a problem with. If the board still clamps onto the splitter you will know the fence isn't the problem.

Personally, I don't think it's the fence. A misaligned fence might push the wood on the fence side towards the blade but it would have no effect on the wood on the other side of the blade and it would seem that both sides have to move towards the center for the kerf to close up enough for that much clamping to take place.

Cliff

[Cliff Rohrabacher]

That happens when the front of the saw blade is thinner than the rear.

Or maybe when the humidity in your shop is swinging wildly

Or when you are ripping 2*4s

Or maybe you simply have a few hunks of wood with lots of stress in 'em.

The Rip fence is best if it's not parallel to the blade but rather leans away from the blade by a few thousandths. Same with a precision sliding table.
The idea is that if the work is drifting off by a couple of thou it won't pick up the aft end of the blade and get all marred up.

[Joe Jensen]

That happens when the front of the saw blade is thinner than the rear.

Or maybe when the humidity in your shop is swinging wildly

Or when you are ripping 2*4s

Or maybe you simply have a few hunks of wood with lots of stress in 'em.

The Rip fence is best if it's not parallel to the blade but rather leans away from the blade by a few thousandths. Same with a precision sliding table.
The idea is that if the work is drifting off by a couple of thou it won't pick up the aft end of the blade and get all marred up.

True for the part between the fence and the blade, but the other piece gets pretty torn up. I used to run this way, and I now set it as perfect to parallel as I can.

[Simon Dupay]

Knotty cedar, white cedar, elm, SYP and cypress will bow and twist like crazy as will 8/4 being thick more likely to move when ripped, but not as bad as you describe it. I check out the saw as others suggested.

[Peter Quinn]

It could honestly be that you have just gotten really unlucky. I'd check the saw out to be sure its set properly, but I have had similar problems with every species you mention and more. Black walnut has some NASTY tension here and there, as does maple. A more likely problem with cedar is case hardening, where the outside was dried too quickly and sort of frozen in place and not allowed to twist or work out its tension as it dried. When you slice it, you release the tension created in the drying process. Look up "Case hardned lumber" on the net or in a lumber book for more on that truly scary phenomenon.

[Wes Grass]

Is your splitter thicker than the blade?

[Steve Clardy]

It seems EVERYTHING I cut recently has a tendency to pinch the blade / splitter to the point where i can't even push it forward anymore. I was cutting some cedar (which I thought was a softwood so it wouldn't have the same tendencies to react like hardwoods) and it pinched the blade so bad I couldn't even dislodge the board from the blade and splitter without the use of a hammer. This had happened with some 8/4 maple earlier in the months, now the cedar, and just now I was cutting some 4/4 black walnut and the stuff pinched so hard that it literally grabbed and ripped out my microjig splitter. Does this happen a lot? I thought it was relatively rare, but I'm seeing it with everything I cut... :(

Common for me, as I cut wood every day. It happens several times during a month or so.

Reaction/stressed wood seems to be more common these days.

I keep a wood door shim laying on the saw table, ready to jam it in the kerf to keep it from pulling/ruining my micro jig insert.

[Brian Kent]

Maybe you need to move to a worse climate. Wood might like getting -40 sometimes.

[Todd Burch]

Find a new wood supplier. Sounds like someone operating the dry kiln is skimping on the cycles and omitting the tension / stress relieving cycles typically done at the end of the drying run.

That's what it sounds like to me. I've had wood pinch the blade stopped before (my first Craftsman TS). But it was underpowered anyway, along with the wrong blade that was dull to boot. I think I was ripping pressure treated 2x4's

Todd

[Matt Armstrong]

It's not the fence - when the blade gets pinched, I can slide the fence away from the workpiece and it's still stuck. Similarly, I aligned it with a dial indicator, it's within a few thousandths from parallel and actually just heads away from the blade, not towards it. Additionally, this happens on about 50% of the wood I cut, not 100%... and I've pointed the fence significantly away from the blade and the results ar ethe same. There is no binding between fence and workpiece when this phenomenon occurs.

I wouldn't think it's the lumber supplier - I'm using both Jackel lumber in Watsonville (highly recommended from other woodworkers) and Southern Lumber in San Jose (a ripoff, sure, but a reliable staple for hardwoods in the bay area).

The splitter is not wider than the saw kerf.

Lastly, when i do manage to dislodge the board from the saw, all of the boards show the kerf closed completely at the leading end. Sometimes this is with only a 12"-long kerf!

I have also let the boards acclimate for 3 months at this point (the walnut, at least). I think really I've just had a bad streak here?

My solution has been to just finish th ecut with a jig saw (no bandsaw :( ) which wastes wood and then requires me to trim up the wood on the jointer. It's wasting a ton of time / wood / enthusiasm through it all...

[Todd Burch]

It's the wood, not your tools. I would take it back to the vendor, showing its improper drying.

Todd

[Matt Armstrong]

It's the wood, not your tools. I would take it back to the vendor, showing its improper drying.

Todd

Yeah, I suppose that's not the worst idea. But quite a PITA.

[Stephen Musial]

Do you know someone else with a saw that you can try a test cut? Or use a circular saw and see if the same thing happens.

[Mike Cruz]

What HP is the motor on your saw?

[Conrad Fiore]

What blade are you using? Make, model, number of teeth, tooth gring and tooth material?

[Brian Kincaid]

I haven't really had hardwood bind up on me but construction lumber (pine 2x12...) binds up on crosscuts!

I use mostly air-dried hardwood, green to dried in my studio (garage).

-Brian

[Bob Barkto]

It's the wood.
No improper setup, dull blade or wide splitter will cause wood to close up the kerf and pinch like that. Only improperly dried wood or reaction/stressed wood will do this.

There's a good chance both those suppliers get at least some of their wood from the same kiln operator. Since it's a recurring problem it might be worthwhile discussing it with them.


...

I wouldn't think it's the lumber supplier - I'm using both Jackel lumber in Watsonville (highly recommended from other woodworkers) and Southern Lumber in San Jose (a ripoff, sure, but a reliable staple for hardwoods in the bay area).

...

[Jack Ellis]

I've had this happen while trying to resaw some ash on my 14" bandsaw. It's possible the lumber wasn't dried properly according to John Thompson, who posts frequently on this forum.

I've never had it happen on a table saw.