Lately as I've been reading through the forum I've heard quite a few times that Douglas Fir is hard to cut. I have a job coming up soon to resaw some timbers that were left over from a timber frame house into smaller timbers for a garage. These beams are at least a few years old (stored inside), and from my understanding they were kiln dried before building the house. Being in the east I've never cut any of this stuff before, and the timbers were pricey.
I'd hate to mess them up. I've only resawn dry timbers/boards a couple times. Some antique chestnut that cut like butter, and some thick walnut (that I had sawn years before) that I cut into thinner boards, the blade dove a little on me in the walnut.
How do you think these will saw out? I'm considering getting one just to try out...I'd hate to cut them into a pile of junk.
Here's a link to some advice I gave to Stephen1 when he was doing as similar job.
https://forestryforum.com/board/index.php/topic,56216.msg814130.html#msg814130 (https://forestryforum.com/board/index.php/topic,56216.msg814130.html#msg814130)
I think most of the basic questions are answered there. Steven updated the topic as the job progressed so you get a good look at all aspects of the job.
You shouldnt have any problems, your blades will get dull quicker and possibly heat up if your cutting long and wide, like Brucer said in his link to Stephens project. Clean kiln dried cuts alot easier. You mentioned pricey what is the ring count per inch and are the beams free of center? Can you show us some pics.
Use sharp blade,s and plenty of lube when resawing Doug fir timbers, I resawed about 20 beams for a customer about two years ago and found that the tight grain and dry wood would heat up the blades as I sawed, I ran the lube with dove dish washing liquid in it and they came out quite nice and smelled really good too ;D. Tim
Brucer, thank you for the link, I hadn't bothered to do a search yet ::)
Redbeard, I say pricey since the timbers had to be shipped in, and one of the guys mentioned that they were dried in a radio frequency kiln since the homeowner didn't want checks in the timbers.
It might be a concern to put very much lube if any into a kiln dried timber. ;)
Most timbers and beams 6x8 and bigger are not kiln dried. Lumber yards around here either have them in there yard or order them in straight from the mill. The water wont bother kiln dried fir, many a house being built in pacific northwest has had a months worth of rain on there kiln dried lumber pkg. before house gets closed in. Even kiln dried cedar which is like a sponge I have resawn before using water for the coolant.
WM recommends using very little or no lube on dry wood
I just resawed several units of 6x Doug Fir and have done some before. You can count on some twist and such so there will be at least some waste. I usesd lots of water on the blade and all was fine. I have manual feed on the head and if I was sawing wide and tried to rush the blade it resulted in dive. Slow down, no dive. I am also running older blades with not alot of gullet left and the sawdust did not clear nearly as well as compared cedar. The cedar was easy, the Doug Fir was o.k.. Just had to slow down a little for the DF. Not a big deal at all.
Also, most of the 6xs were #1 or Select Structural. You will end up with sizable knots even in those grades. High grade timbers are allowed to have some knots. If you are sawing into 2x you will not end up with all #1 as you might expect.
DF is hard to cut, but dried cants (and I assume the cut widths would be 12" or less) should be fairly easy.
I think you will find things will work out well, I wouldn't worry about a practice run.
I would like to add something for the cicle sawyers and swing mills on DF when cutting structual framing material and beams, There is a big difference in blade exspence they are very competitive with commercial mills . Compared with bandmill blade exspence I cut 2x4 s for my self but I cant sell them due to exspences. Beams and specialty parts like 1x10 siding I can make a profit cutting DF. The water for coolant I disagree I have to cool blade or it will get brittle and break after it cools down been there done that DF will heat a blade up really fast.
The issue with lube is to keep the blade cool, I had no issue with build up only heat. the timbers that I resawed where very tight grain and 150 years old and hard as a rock!. Tim
Using water will cause the fibers to expand and rub the body of the blade. I've resawn dry timbers and too much water made cutting worse than using less water. Just a drop every few seconds of water and dish soap did well. If your blade is heating up too much, your mill might be out of alignment
Quote from: ohsoloco on May 13, 2012, 10:14:33 AM
... one of the guys mentioned that they were dried in a radio frequency kiln since the homeowner didn't want checks in the timbers.
OK, I know where those timbers came from originally. It's a radio frequency vacuum kiln and it will easily dry really big timbers in a few days. The kiln is about the size of a boxcar if it's the one I'm thinking of.
Just about everything they sold was FOHC, even 12x12's. My timber-framing customer bought a bunch of their 8x8's back in 2008 and had me resaw them down to make handrails and interior trim.
Not hard to saw. I did it with 10 degree blades. Lots of lube -- just water with a bit of windshield washer fluid. Make sure your blade alignment is good, use sharp blades, keep the carriage speed up, and watch the blade tension like a hawk. If the tension starts to drop, sock the fluid to it. You don't need to worry about the wood expanding from the extra fluid on this stuff.
If you're dealing with stuff over 8" wide, you
might need to go to 7" blades.
If the weather cooperates, I'll be sawing these up on the 29th of this month. I plan on using new blades for this job instead of my resharps (I sharpen my own). I usually run a little Dawn or Pine Sol in my water. I'll let you all know how the day goes.
I just resawed half a dozen very dry Douglas-Fir 8x8's today. They had been stored under cover for 10 years. Some were a bit twisted and/or bowed so the customer asked me to square them up and take them down to 7-1/4" square.
I used my regular 10 degree blades and a moderate amount of water/windshield fluid mix to keep the blade cool and it worked just fine. As a starting point with very dry D-Fir I turn the fluid up to the point where there it just barely sprays onto the face of the timber where the blade enters.
I hope there isn't much in the way of twist in these timbers, a few of them are 16' or a little more, and my Norwood can only cut 12-1/2'. I told them that since they're already timbers, we should be able to cut the 12', and then slide the timbers down to finish the cut as long as they are still straight. We shall see...
Any twist shows up pretty quickly when you lay the timber on the deck of your mill. I found a little twist in a few of the RF-Vacuum kiln-dried timbers.
The trick when you have to "shuffle" something on the mill -- a twisted timber or a log -- is to not lose the orientation of the partly cut face during the shuffle. Get this right on the first face and the other faces are easy.
If your mill is level from side to side, make a thin cut off the as far as you can. Then curl up the bit you just cut and put a level across the new face to be sure it's level. Then shuffle the timber and check the level again. Shim the corners of the timber as needed, using plastic paint scrapers.
Thanks for the tip. I think the long timbers are 16 or 18' at the most, so I'll still have 6 feet of cut surface to check for level after sliding the timber down. Wish me luck :D
Good luck! ;D ;D
You'll do fine. PM me if you've got any problems/questions.
This will be a one day job, so I'm on my own if I have any problems :D Just hoping to get my new coil by then. Got the serial number off of the engine, gotta call the small engine shop back tomorrow.
After a few delays I was finally able to get those timbers resawn today. I used a new blade (one did the whole job), and the timbers cut like butter. Reminded me a lot of our hemlock, cut nice but can fill your hands with splinters if you're not careful. The guy said the timbers were dried in a conventional kiln, but they were all free of heart so there was very little checking in them. I used a small amount of water on the blade, sometimes making cuts without it, and it stayed nice and clean. The shims were a must, I had a handful of wood shims with me, and they were used on most timbers b/c almost all of them had a little twist to them.
I figured you wouldn't have many problems. It's very nice wood to saw, unless you hit a beam with a big pitch pocket.
Even the tiniest amount of twist in a beam shows up when you put it on the bed of a level mill ;).
Douglas-Fir "slivers" are most annoying. They're about 1/16" long and just barely penetrate the surface of the skin (usually vertically). They're in just deep enough to irritate whenever they brush against anything and they won't scrape out.
You pretty much need to use tweezers to get them out (I use a pair with a built-in magnifying glass). That's why I always where gloves on the work site.
Glad it worked out good for you and the customer.