Sitka Spruce

[DGK]

I have been milling some Sitka Spruce from Alaska this past week and have found it to be rather difficult to mill. It has a tendency for wavy cuts if faster than slow and or near knots and blade marks if slower than than the slow cuts. Sharp blades (1 1/4 10/30 24 set) 2300 lbs. band tension. Some stringy fibres on the blade exit when cutting through grain at rift/quarter angles. Any ideas, thoughts or suggestions?

Don't ask about the waves when quarter sawing near knots. @#<"%$#

[SwampDonkey]

Will the lumber plane out smooth or stay kind of rough? Could be severe spiral grain. When we cruises those Sitka stands of the BC coast we did a quality call on severity of spiral grain. We would look at a height between 5 and 6 meters and visualized the log sliced in 10 vertical sections the length of the log. How many sections the grain crossed was the severity of the spiral. Crossing 6 out of 10, was called a 6 obviously. I think more than 5 sections crossed was not desirable in a log. Look under the bark to see how much it twists along the grain.

[DGK]

I have not tried planing it yet but this stuff is quite straight compared to some of our Yukon Spruce. The slope of the grain on the worst log was at most 1" over 8", some of the logs the grain runs pretty true. I had heard that it was a difficult wood to mill from others, kind of wondering about blade options. Here's a pic of yesterday's log that was milled into an 8 by 12 by 21' beam.

[Papa1stuff]

Try more set (30 ) ,that may help!

[Shamus]

I've milled up a fair whack of sitka spruce with a circle mill (D&L Doublecut) before, and yes it was ornery. The lumber came out very fuzzy, spiral grain or otherwise, this species seems to have long fibers. I used wedges to help with the cuts, and sharpened frequently. Nice wood though, no board warpage that I can recall, made great rafters.

[DGK]

Just got off the phone with Woodmizer Blades, they suggested trying a 4 deg hook for the knottier logs and also a thicker blade. I am presently using .045" so I guess I'll have to try the .055".  Anyone else using this combo? Thanks for the replies.

[SwampDonkey]

Not knowing where/how you checked the grain here:

A tree puts on layers like placing a stack of cones on top of one another representing each year of growth. Near the top of a cone the slope is faster than at the stump for instance because your looking at the end of the rings of the late wood area (darker). Thus, realize the grain on a sawed slice of board has a different slope than in a cylinder where you can see the true spiraling like a staircase following separations/checking along the wood rays and not the growth ring unless it has suffered from compression failure (brittle heart).  You will usually find an open seem or mark/wound of some sort where you can judge the spiraling by taking a 1 meter section, visualize it sliced into 10 sections and see how many sections the seem crosses. Thus, checking under the bark gives a better idea of spiral grain and be aware it is probably worse the closer to the pith in the juvenile area. Just elaborated on my previous post some.

[Jasperfield]

Sitka Spruce is THE prime wood used for aircraft wing spars as well as most all other wooden aircraft parts.

It brings very big bucks when sawed, dried, & processed for this purpose.

Google "Aircraft Spruce & Specialty" and take a look for spruce.

[Brucer]

7 degree blades, 1-1/2" wide, 0.050 thick.

[barbender]

Sounds like it saws like white spruce.

[DGK]

Thanks for the replies. I have some 4 deg and 7 deg saws at .045 and .055 being shipped from Woodmizer. A little experimenting will be in order.

[captain_crunch]

I have never tried sawing it but after logging it is wood is as narly as the limbs good luck ;D ;D Swear you could drag one 10 miles down Freeway and not hurt any of the limbs >:( >:(

[backwoods sawyer]

I milled up some large logs, cutting 20' 2x12. I found that the fibers of the wood were wrapping around the gullet. I set the saws up an extra .005 and that helped. The only wood that I have heard pull my little diesel down. I was running .055, 10* saws. The production mills have struggled with spruce with the heavy bandsaw's and the thin kerf edger saws as well. It has so much resistance that it over heats the saws. Frequent saw changes helped them with the spruce. Therefore, I did the same thing and changed saws every hour and a half and that help as well.

[DGK]

When cutting a 21' 8 by 12 beam, the saws were heating up during the last 3 or 4 feet. This caused the blade tension to decrease and then the cuts went wavy. Fortunately, I left some wood to trim, so on the trim cut, I opened the lube wide open to cool the blade once the tension started to decrease. The blade tension stayed within limits and the cut was better.

Gonna have to get this figured out as I went and picked up another load of the Sitka today.

[fuzzybear]

you also have to remember that sitka is alot denser up here.  With our shorter growing season the trees are like steel. When it's dried you have a hard time driving a nail straight.

[pineywoods]

You guys that have sitka spruce available may not be aware of a high dollar niche market. There are quite a few home-built airplanes flying, many of them made from wood. Sitka spruce is the wood of choice. From a structural standpoint, the only material that is better is carbon fiber. Only bad thing is wood rots. Most wooden ladders are made from sitka spruce.

[Hilltop366]

It is also used for the tops of guitars and other stringed instruments.

[SwampDonkey]

When I cruised those west coast sitka I was told on a number of occasions the 250 foot tall ones I was wrapping d-tape around were $20,000 trees. Not as a log but the wood products from them.  DNR wouldn't let us cut most all the ones we measured, usually because of site sensitivity, slide potential and such. A lot of the time they were growing on old slide fans. ;D That was under new Forest Practices Codes, however I think those codes got overhauled since then as they were costing the industry a lot of $$ to do business. In fact it was a boom for about 4 years and then bust when the costs caught up.

[DGK]

Here's an update to what finally worked for me sawing the Sitka Spruce. Woodmizer sent me a few samples of the 1 1/4  7 degree in both .045 and .055. Both of the saws cut better than the 10 degree. There is a wider window between leaving blade marks from being too slow and wavy from being too fast. The deeper gullet of the 7 degree definitely removes more of the sawdust during the cut. I have increased the set to 28 thou and not sure if it really makes too much difference from the factory set. The .055 saws seem to be easier to avoid a wavy cut but are a bear to handle. I recently ordered and received a box of .045 7 degree saws for the regular sawing and will keep the .055 7 deg sharp and available for the difficult logs.