What is that stuff that builds up on our blades?

cutterboy · March 26, 2012, 08:48:04 PM

That stuff that builds up on our blades..... what actually is it? With pine I can understand. It's the pitch. Touch a fresh cut pine log and you get it on your hand, it's sticky. I can understand how pine pitch can coat and build up on a blade. But what about hardwood? What is that stuff? Is it some kind of sap, or is it minerals from the wood or maybe mushed up wood fibers? I just finished sawing some hickory logs and after the blade dried it was coated with very hard crusty stuff. Does anybody know what the stuff is? I wonder about things like that.

Thanks and happy sawing, Cutter

POSTON WIDEHEAD · March 26, 2012, 08:59:31 PM

It's a mixture of everything you have said. I have found even if I turn my lube up, I still get build up on my blade.
When this happens, I keep a spray bottle of DIESEL FUEL beside my mill. About every 5th pass through a log, I spray my blade with the diesel and it cleans it slick as a whistle. In fact you can hear the blade "quieten down" when it gets clean. And at the end of the day or when I change blades, I spray it with diesel fuel to clean it before I send it back to WM to get it re-sharpened.

Magicman · March 26, 2012, 09:05:45 PM

It is not unusual. It's just powdered sawdust mixed with sap or blade fluid that has dried. Hardwood buildup. I run the sawmill with the blade lube on full force to clear it off. This buildup can cause the blade to wonder in the cut same as a pitch buildup.

mikeb1079 · March 26, 2012, 09:52:40 PM

QuoteThis buildup can cause the blade to wonder in the cut same as a pitch buildup.

good point mm. i had this happen to me while sawing some white ash. at that point i was using no lube whatsoever and i was getting very very wavy cuts. consulted the forum and started using a healthy amount of water with a touch of cascade soap. worked like a charm.

customsawyer · March 26, 2012, 10:14:56 PM

Mostly it is sawdust. When you start getting build up on the blade you need to turn the lube up. In hickory I turn the lube up all the way as the sawdust is very fine and will bind with anything.

petefrom bearswamp · March 27, 2012, 10:12:54 AM

Ash is bad.
I rarely use any blade lube in hardwoods except ash, unless i lose blade tension due to heat.
On softwoods I only use it sparingly and rarely in Hemlock or Spruce.
Diesel works for me in very pitchy woods.

Chuck White · March 27, 2012, 11:25:51 AM

I agree with Pete, Ash is the worse.

Need lots of lube (water/soap) going soon as the blade touches the cant.

When I'm ready to change blades, I always open the water all the way for a few seconds to clean the blade.

CalebL · March 27, 2012, 12:10:32 PM

Quote from: Magicman on March 26, 2012, 09:05:45 PM
It is not unusual. It's just powdered sawdust mixed with sap or blade fluid that has dried. Hardwood buildup. I run the sawmill with the blade lube on full force to clear it off. This buildup can cause the blade to wonder in the cut same as a pitch buildup.

I have noticed when I run my blade lube at full open, I get a lot of buildup on the idle side blade guide. It develops a paste like substance and sometimes it gets thick enough that it stops the guide from spinning. It's a balancing act for me to get the right amount of lube to keep my bands clean.

Brucer · March 27, 2012, 08:26:22 PM

The sawdust flies out of the cut on both sides of the blade. Some of the stuff coming out the top gets pinched between the inboard blade guide roller Then the drive side band wheel compacts it. Then the idle side band wheel compresses it even more.

There's a little finger just beside the inboard blade guide roller that is supposed to deflect most of the sawdust (if you keep it adjusted). Mine got bent slightly and it actually did a better job of shedding sawdust.

dblair · March 27, 2012, 08:37:36 PM

why do we get it on band saws and not on the circle saws ? the only thing I can think of is clearance . I just cut 18 logs 12 to 22 inches in diameter about 18 ft long and didn't get any on my circle saw . If it had been my band saw there would have been a buildup that water and dish detergent would have been used to cut it .

cutterboy · March 27, 2012, 08:59:57 PM

Quote from: Magicman on March 26, 2012, 09:05:45 PM
It's just powdered sawdust mixed with sap or blade fluid that has dried.

Thanks Magic, that's a straight foward answer I can understand.

Customsawyer, you're right about hickory sawdust being fine. It was so fine it hung in the air. I had to wear a mask.

dblair, thanks for the pics.

A question for those of you who use diesel on your blades. Does the diesel get into the lumber and make it smell like diesel?

bandmiller2 · March 27, 2012, 09:20:08 PM

Dblair,you won't get it on your circle saw because you don't dribble water on it.There has never been a drop of water put on my bands.I use diesel and oil on a wick that rides on the top and bottom of the band and never had any problem buildup or rust.Frank C.

Al_Smith · March 27, 2012, 09:22:43 PM

I cannot comment on a circle mill but I can on a table saw .It does happen especially with pine .Easy off oven cleaner peals it right off .

I have no idea how many sawyers on here are wood workers but let me tell you build up on a blade really effects the smoothness of cut .

Larry · March 27, 2012, 09:53:54 PM

I've noticed that I can mill walnut all day with little or no lube. 10 minutes after I start edging (mostly sapwood) walnut I have a heavy build up of pitch unless I get the water going from the start. Has to be some kind of difference in the sawdust for it to build like that. Maybe that's why they call it sapwood.

Al, I used to use oven cleaner on my table saw blades. Had a factory rep from Freud tell be the lye in oven cleaner attacks carbide causing a slow breakdown.

ALWOL · March 27, 2012, 10:56:38 PM

Another reason, besides clearance, that circle saws do not collect a build-up, is the size of the chips/dust that it is removing. A good sharp saw will throw chips almost big enough to knock you down!

Alan

Al_Smith · March 28, 2012, 08:08:45 PM

Quote from: Larry on March 27, 2012, 09:53:54 PM
Al, I used to use oven cleaner on my table saw blades. Had a factory rep from Freud tell be the lye in oven cleaner attacks carbide causing a slow breakdown.

Coincidently those are the blades I use .However after I let the oven cleaner sit a spell I rinse them off with water .

I suppose a person could stick them in the dish washer but I fear the wrath of Mrs. Smith in doing so .

Ron Wenrich · March 28, 2012, 08:52:51 PM

I get a buildup on the saw tooth on the circle mill when sawing ash, white oak, and hickory. No other species gets that buildup. Put a tulip poplar on, and it will clean everything up. I was always told it was due to the tannic acids in those species. Not sure if that's all true. But, I haven't gotten it in hard maple, and ash isn't really all that hard and it is the worst.