The trouble with knots

squarpeg · November 19, 2021, 10:39:34 PM

Any advice welcome. I have mostly cut white pine, but now I am into a whole grove of really knotty eastern hemlock. It is also getting very cold freezing at night. The other day I was cutting 2x6's and they were really a sad bunch of wavey crap. Going to have to run them through a joiner or table saw. Around each knot I get a blade dive or rise. Tried tightening the blade, check the guides. New blades run better but I am burning through them. Not long before the wave returns. What is best procedure?

WV Sawmiller · November 19, 2021, 10:51:18 PM

What blade profile are you running? I'd suggest 4* hook angle any time you have very hard wood even if it is just knots between very soft wood. Many of us have the same problem with spruce, hemlock, etc.

YellowHammer · November 19, 2021, 11:17:06 PM

I agree, drop your hook angle.

Patrick NC · November 20, 2021, 04:09:39 AM

If I remember correctly you have a norwood hd36. Are you still using the ceramic guides? If so I suggest switching to roller guides.

moodnacreek · November 20, 2021, 05:29:58 AM

Frozen hemlock knots have been compared to a mother in law's heart.

Bruno of NH · November 20, 2021, 07:58:06 AM

My 2 cents
Did some ugly Hemlock yesterday
Had to switch to a turbo 7 in .055 nice and flat cuts.
My next choice would be .050 frost notch bands but are out of stock for a couple more weeks.

DMcCoy · November 20, 2021, 08:17:11 AM

My sympathies, I hate hard knots.
For me I resharpen my blades about twice as often(7 deg.). It makes sense that hard knots will dull the teeth quicker. Never tried 4 deg, but that makes sense.

moosehunter · November 20, 2021, 08:40:56 AM

Another vote for 4°. It works for me.
mh

DesertHobo · November 20, 2021, 10:39:13 AM

I tried 7's in the ugly spruce my neighbor wanted cut up, had way better results using a 10 degree bimetal blade. If I was cutting it more often, I'd give the four degree a shot as so many others are suggesting.
Also, as Patrick suggested, give the roller guides a shot if you're able.

squarpeg · November 21, 2021, 05:52:35 PM

I am running a kasco 10 degree blade at the moment. With the ceramic guides. Not sure norwood has a roller guide option will look into it. Also see if I can get a 4 degree blade. Is that a specialty blade? Been buying from SE metals have to call and see if they offer it. Thanks

PC-Urban-Sawyer · November 21, 2021, 06:34:58 PM

A lot of people have put Cooks roller guides in place of the ceramics on the Norwoods...

47sawdust · November 21, 2021, 08:04:11 PM

I've only been sawing for 14 years.I was totally confused by all the blade choices.When I started using the 4° blade my blade confusion went away. I still have plenty of other confusion though.
I have an LT30 with a 24 hp Honda.I saw pine,hemlock and the dreaded knotty spruce.Sometimes frozen.
I have the best luck with the spruce sawing when frozen.
I don't use any other blade now.Mine are also WM blades

Patrick NC · November 21, 2021, 08:34:48 PM

Quote from: squarpeg on November 21, 2021, 05:52:35 PM
I am running a kasco 10 degree blade at the moment. With the ceramic guides. Not sure norwood has a roller guide option will look into it. Also see if I can get a 4 degree blade. Is that a specialty blade? Been buying from SE metals have to call and see if they offer it. Thanks

Norwood has a direct bolt on roller guide kit for the hd36. Its what I have on mine. My Norwood hates 10 degree blades. I use 7s for everything.