Why is my cherry burning? - Page 2

michaelgarner · 09-03-2006, 06:17 PM

Originally Posted by McRabbet

We had a discussion about push versus pull on RAS several months ago -- I am a strong proponent of the push cut for cross-cutting since it is not a climb cut. The blade is pushing the stock toward the fence and is cutting the same way a table saw cuts. The stock must be held down as there is a slight tendency for the stock to lift. With a pull cut, the teeth may grab as the blade tries to climb onto the stock. And, as we said the last time when this was discussed, I never rip cut on a RAS because I believe it is too dangerous (DAMHIKT). Was this cherry cut with a pull cut? If so, that may explain the burning (along with the other factors DaveO mentioned) -- you may have taken a slow pull to avoid grabbing -- my recommended faster cut is with a push cut with a sharp, trued blade.

Rob

I remember that discussion too, I am amazed at the level of knowledge we can collect together.

jaustin · 09-03-2006, 06:26 PM

Moisture content i do not know but i bought it kiln dried a year or two ago.I think it may of been even longer.It has been sitting in my building since then.

going to try and pull it instead of pushing.

Ray Martin · 09-04-2006, 09:30 PM

Not sur if I'm putting the pieces together correctly here but... if woods like cherry have a higher sugar content which makes them burn more easily and too much contact with the blade or blade out of align makes for more burn, does it follow that using a thin kerf blade can result in more burn?

Ray

DaveO · 09-04-2006, 09:47 PM

A thin kerf blade shouldn't result in any more incidents of burning than a full kerf blade in the same well tuned saw. A TK blade has thinner teeth and a thinner plate, than a FK.
Dave

Travis Porter · 09-04-2006, 10:47 PM

But a thin kerf blade can and will flex more than a full kerf blade.

Dave, you remember when you came by and my miter saw was not cutting right? I put a full kerf forrest in it and it has cut perfect since. I also changed my tablesaw a while back to full kerf and it makes a lot of difference in cherry (been cutting some up).

DaveO · 09-04-2006, 11:16 PM

Travis, I agree with you, and that is why I qualified my statement with "in a well tuned saw". Providing ample power and perfect alignment and not pushing the limits of thickness, you shouldn't get flex enough to cause burning with a TK blade. We can only strive for perfection like that

Dave

jaustin · 09-04-2006, 11:43 PM

I tried pulling the blade thru the wood.
one thing i found out i lost cross cut capacity and second i tried pulling thru a piece of wood and it grabed it. Didn't like that.

pushing it thru i have never had that happen.

still burned goingto have to check alignment of it.
Been to busy.
Got a big order of the pistol racks to build.
Started on them today did have a little burn on them. they are made from red oak. But it sanded off plus it will be covered and not seen.

DaveO · 09-04-2006, 11:59 PM

What kind of blade are you using??? A negative hook angle blade will give less of the climb cut effect while pulling the carriage to you. IMO that was the way the saw was designed to be used. Going the other way (pushing) causes the teeth to cut up through the board, running a risk of lifting or shifting it .

Dave

Tom Dunn · 09-13-2006, 10:27 AM

I was cutting some pieces of cherry about 2"x3" to a length of 18 inches on my table saw. Had trouble with burn on the ends(dull blade maybe) and, since they would be exposed, that was no good.
Might be kind of a "hack" solution, but I ended up cutting them first to about 18-1/8", then going back and taking that last "wisker" off in another pass. Saw's not really doing any "work", so no burn.

Dusty Sawyer · 09-13-2006, 11:42 PM

You have probably already checked this, but I will float it out there since there has been nothing to solve this so far.

Looking at how the burn does not occur until you are most of the way through the piece, and also how the corners only are burned on the smaller pieces off to the right, I might be inclined to check and see that the pieces have adequate support on either side of the saw and that the back stop block is flat all the way across the back of the saw.

In other words, is it somehow bowing the further the blade goes through it. Or possibly that the back support on the saw is not a flat surface and that is causing a small level of pinch?

Again, just a possible cause. You have probably already checked it.

David

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