sawing spruce

[wannabeonetoo]

Just a question on sawing white spruce.
I had aguy come in last summer and cut about 1500 b/f for b&b siding.The question is why did some of the boards turn out wavy and some were ok ?He was quite new at the "sawing game",and I certainly don't know the tricks.
Could his feed rate have been too fast ? or blades dull or poorly set? How about the knots ? He said the knots in spruce are the hardest to deal with,they deflect the blade and make the cut wavy .What about lube ?
But how come some boards were fine (probably 75%).
He used a WM with 16hp & power feed (older LT 30 ??)
He charged top $ for his service even though still on the "infamous learning curve".(when the job was finished and he told me the total ,his rate was more than he had told me previously)I balked a bit but paid anyhow (he was a former co-worker).Needless to say no positive references coming.
Also the battens were so wavy I had to either rip new ones or salvage on table saw(more work!).
Not meant to be a rant ,just one more reason to take contol of my own lumber making.
I have two more projects requiring b/b siding and plenty of my own spruce ,so if I get a mill I'd like to learn a few tricks ahead of time .
Thanks
            Steve

[Nate Surveyor]

Wavy?

do you mean that they were not consistent in thickness, or that they warped after drying?

Assuming you mean cut wavy, I'd suggest that that as the blade on the mill got duller, quality of dimension went down. Actually there are many things that can go wrong, but that is just an idea. I don't own a band mill, but I did read alot.

Slower cutting speeds, and keeping the blade guides close to the wood helps too.

I went with a Peterson, over a band, because I found a Peterson at a price I could afford, before I found a band I could afford! But, when in good tune, it is hard to beat a nice cut board!

I am like you... good dimensions mean alot to me.

Nate

[Tom]

Knots will cause waves, but, so will a dulling blade or one with too little set.   Some woods, Like Loblolly Pine, are notorious for providing wave.  It's the wide and soft early wood and the strip of hard late wood following it that cause the blade to follow the grain.  Woods like this will be wavy on each surface and, when looked at from the side, look like a ribbon.   The only remedy is a razor sharp blade and more set.

Actually, Charging is part of the learning curve.  I think you were right in paying him and right to be hesitant to use him again without observing his ability to have learned.  If he changed the rate on you, that isn't right in anyone's book.  If he charged by the board foot, he is making an effort to compensate for his lack of knowledge, but by not recognizing his faulty product and giving you a break, I think his long term prospects are suspect.  :D

One of the lessons we should all learn is to stop when we are making unacceptable product.

[ohsoloco]

Did you notice what part of the log the wavy boards came from?  I've cut quite a bit of blue and norway spruce, and I find that I get the most wavy boards from the first few cuts of the log...especially when I don't have a sawn edge up against the log posts.  The knots are bigger on the outside of the log as well.  The easiest way to tell where the boards came from in addition to the size of the knots is the weight of the boards.  The ones that contain the sapwood are much heavier than boards cut from the inside of the log. 

Sometimes if I get a real knotty spruce log, I'll just slab it heavy so I'm not cutting any flitches.  After it's squared up I'll take a 1/2" board off of each face to get rid of the waves.  It doesn't always completely eliminate the wave, but it makes the peaks and valleys much closer together.

[rl]

          I DONT KNOW IF YOUR SAWER WAS BEING SLACK ON BLADE CHANGES OR NOT.       HE WAS SAWING THE WORST WOOD THERE IS TO SAW IN MY EXPERIENCE .I'VE TRIED ALL PROFILES OF BLADES ON WHITE SPRUCE AND STILL GET ROUGHER LUMBER THAN ANY OTHER SPECIES . I TELL MY CUSTOMERS WHAT TO EXPECT . KNOTS ARE HARD AND SOMETHING TO DO WITH THE FIBERS. THE BLADE TENDS TO FOLLOW THEM                                           RL                                                                                                                                                                         

[Minnesota_boy]

Yes, white spruce is very hard to saw straight.  Of a box of 10 blades fresh from resharp, 5 to 7 will cut it reasonably straight.  The rest get put back in the box to wait for pine or hardwood which they saw just fine.

If I remember in time, I saw the spruce a bit oversize.  Once the cant is squared it will be easier to keep the cut straight.  Then I go back and make an extra cut on each side to take the wave out.  Makes much better looking lumber.

[Tom Sawyer]

Don't be too hard on the guy as far as wavy cuts, unless a large percentage was like that.  As has been said, spruce is notoriously hard to cut because the knots are so hard.  Blades must be extremely sharp and well set. 

[woodmills1]

I find spruce very hard to cut.  The knots are so much harder than the surrounding wood.  Requires a very sharp blade that is well set at over .025".  Alittle dirt and put on a new blade.

I also find waves in spruce, pine or hemlock when the blade passes from a wide part of the log to a narrow part during the first or second pass on a given face.

[SwampDonkey]

Mills here want nothing to do with open grown/cow shade spruce, not even the pulp mills.

[LT40HDD51]

Pasture spruce!!!  8)  I love seeing a whole pile of that at a farmers place, he always wants it made into 1x4 or something too  ;D.

Spruce has given me trouble before and probably will again, and I know my mill and blades are well tuned. The only thing that has seemed to help is heavier (thicker) blades. Thats what WM recommends the 50 and 55 thou blades for, difficult sawing conditions.

...Alittle dirt and put on a new blade...

For sure. It can be amazing what a bit of sand or dirt can do to a fresh blade. Might keep cutting something easier like pine or poplar, but in a log that is already tricky to cut...