Lubricant for Severe Pitch Buildup
Tooth pitch and lubricant choice may be some help when sawing wood that contains unusual amounts of pitch. March 16, 2015
Question (WOODWEB Member) :
I just came from the only bad saw day I ever had in seven years. I’m looking for some advice on blade selection from fellow LT40H 38 hp gas owners. I was cutting 18" red pine that had been dead standing for one-two years and I could not get any feed rate worth doing without serious waves every time I hit a knot or tried to speed up.
I am running water with approximately 1 ounce of Pinesol per gallon with a liberal squirt of dish soap. I was using 10 degree hook .042 Woodmizer blades. I called Woodmizer Northeast and they recommended trying four cuts - no lube then lube to clean but the pitch built up like crazy. I tried a 4 degree and it was a little better but not much. I ordered some .055, 7 degree which came today but have not tried yet. Pitch was building on the body which one blade company says is not enough set but Woodmizer resharp doesn't custom set I was told. I have also had this problem in some 20-28 " spruce but not as bad. The mill is one year old and just had a service call in late May. Any suggestion from more experienced sawyers on blade selection for all wood types would be appreciated!
Forum Responses
(Sawing and Drying Forum)
From contributor R:
So the tree started dying a few years ago and the insects sensed it and moved in. The tree responded to the attack by generating large amounts of pitch and now you have to deal with it. I had some similar experiences with dead red pine also. I have no further suggestions from what you are doing. Run very sharp blades, slow down, find some other logs to cut and be happy you are working outdoors.
From Gene Wengert, forum technical advisor:
One thing that encourages sap buildup is heat generated from the cutting process. So, how much set do you have? If it is too little, then rubbing and heating and pitch buildup is likely. My preference would be 4 degrees and 0.055 for dead wood. For keeping the blade clean, try Cascade and water. Then when you see some build up, many people use a little diesel. It can be sprayed on the blade and then the Cascade and water will wash off the buildup. Of course, this spray must be used cautiously and also it would not be a good idea to have an unlabeled bottle of liquid lying around either.
From the original questioner:
I guess I'm glad I only have about four sticks left of the stuff and will chalk it up to a valuable learning lesson. Thanks Gene, I was running Woodmizer set which I was told was .024 on a 10 degree .042. I was going to switch and try a little diesel next. Any other 40 owners that could wade in with their favorite blade selection by wood if it differs from Woodmizer’s website would still be appreciated.
From contributor K:
In the shop, when I know I'm likely to get pitch build up, I keep a stick of paraffin sitting on the table that I touch to both sides while it is running to coat it. I think it helps and last pretty long too. While I have not tried it I also keep a big stick of graphite about 15' away on my stroke sander. I have a feeling it might even work better, being a harder stick. You can find the paraffin in any good grocery store in the canning section.
From Contributor P:
I have found a lot of very good information in this forum and I like to read and learn. My English is not so good so to be able to understand some things correct, may I ask about two things from this thread: Can the hook angle be so low as 4 degrees? Does the recommended set of 0,055 (1, 40 mm), for a 0,042 thick blade, means the total set or does it means 0,055 per side? I have a "Metesa" log band saw, about the same size as the LT40, but I have to push the saw, no power feed. That way I know that hook angles less than 7 deg. means much more feed force to get the blade to cut. I have never used set more than 0,030 per side. I cut Swedish spruce and pine, dried and fresh and also sometimes frozen.
From contributor V:
You might try a blade with 3/4 pitch rather than 7/8 pitch. I don't know why but a 3/4 will cut blue spruce straight while a 7/8 is all over.
