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Board Feet Per Meter

Started by Bigshooter, March 22, 2017, 04:58:12 PM

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Bigshooter

Hello everyone, I am a newbie to this forum and have been milling on my Timberwolf mill now for just over a year. I'm located on Vancouver Island one of the most beautiful places around. I was looking for information on estimating how many board feet of wood can be sawn out of a cubic meter?
I have a job coming up and its based on me buying the logs then running them through the mill. So I'm curious how do I determine the amount boards I will get? Say a logging truck load, how many board feet in a load? I did find a calculation online but would like to hear your guys opinions.

tacks Y

I was getting 3500+ per tri axle load to be sawed by the Amish. Nice logs tho. I sold some hemlock to a guy said he would buy down to 8" he found out quickly trucking was to much for the yield. Size matters.

Bigshooter

A smaller tri axle like a bumper tow for a pickup not a logging truck?

tacks Y

This was a full size truck here in Pa, they haul 23' pole wood. He ran 3.5K to 4K board feet a load, this was also cut on a circle mill. So more waste, but good logs. I was cutting the biggest off my property for my house.   

longtime lurker

ummm - depends on the logs. More importantly it depends on the size of the logs and how much defect is considered acceptable in a log.

Cubic meters is an unscaled measure of volume okay. So mid point diameter by girth tape (or circumference divided by pi) , divided by two, square that, multiply by pi, multiply by length= volume in cubic meters

A 2.4m (8') log with a diameter of 720mm (28") is near enough a cube. It scales at around 288 Doyle.
A 3.6m (12') log with a diameter of 600mm (24") is near enough a cube. It scales at around 300 Doyle.
A 4.5 m (15') log with a diameter of 520mm (21") is near enough a cube. It scales at about 271 Doyle.
A 6.0m (20') log with a diameter of 460mm (18")  is near enough a cube. It scales at 245 Doyle.

Where it gets wide is 2x 20' logs with a 13" mid point. That's also roughly a cube, but will scale a whole 160 BF Doyle.

Recovery off the above will vary widely. Buying unscaled by the cube you can get a real hiding in small or defective logs.

What you need to do is establish what the minimum standard of a log is: small end diameter, length, slope of grain, bend deflection, pipe, knot size, percentage of cross sectional area that can be defective. This is really important because when buying by the cube or the ton or other volumetric measure, theres no allowance for defect. Its good and its in or its out and its bad... you dont get to deduct so many BF from a scaled measurement because theres a 15° bend half way up the log... if 15° bends are okay its all okay. If 15° bends arent okay they cut it on the bend and try and get a length each side of it and the bend stays in the bushes.

At least that way you know exactly where the line is in terms of just what trash might show up in your yard with bark on it.

Trucks usually load by weight so you'll find published data that gives you wet wood density of most common species, then you can kinda average out how many cubes to the truck load in a given species.
The quickest way to make a million dollars with a sawmill is to start with two million.

Brucer

I've cut over 400,000 BF of Douglas-Fir and half of that was from logs that I purchased. I kept very accurate records of the stuff I bought. Here's the numbers.

I was sawing mainly timbers for the timber frame industry, all with no wane. I was consistently getting about 200 BF per cubic metre. I also recovering about 100 BF of side lumber (mostly 1") out of each cubic metre while I was sawing the timbers. So total recovery was 300 BF per cubic metre. The timbers were selling for twice what I could sell the 1x for so I naturally wanted to maximize the timbers.

I was buying straight 43' and 52' Peeler grade D-Fir with 12" tops. That gave me a lot of flexibility to buck individual logs to match the timber sizes. Smaller logs than that will give less recovery.

I always got the best recovery when I had a backlog of 3 orders or more, with a mixture of sizes. That let me mix and match to get the most out of each log. A good chunk of my profits came from sitting down with the cut lists and a pencil each evening -- kind of like doing a 3D jigsaw puzzle.

My recovery dropped about 10% when I only had one small order in the backlog, or when the order was only for one size of timber.

I had no trouble selling the 1x (actual dimension was 7/8" thick), so I could just saw it and stack and sticker it, knowing it would sell eventually). My two extremes were A) 13,000 BF of 1x of various sizes piled in the yard and no buyers in sight, and B) no 1x at all, and people paying me timber prices to saw up 8x8's into 1" lumber :o.

I would never saw 2x4 or 2x6 side lumber, unless I had a specific order for it. Lumber yards were selling it for less than half what I would have to charge. I was surprised to find a fairly high demand for rough-sawn, full dimension 2x8's. I made a lot of this when I had a big order for 8x12 timbers and I was able to sell it for somewhere between 1x and timber prices.

One key thing about good recovery. I was paying premium prices for premium wood. Before I started buying my own, the timber framer I cut for was buying whatever logs he could get his hands on. On average he was paying 2/3 of what I ended up paying, but I could only get 200 BF per cubic metre out of his logs -- bottom line, no difference in income, but a lot more waste and wasted time with the cheap logs.

If you are looking at a different species, your recovery may change. Western Red Cedar has quite a bit more taper, for example, than D-Fir. This usually translates into more waste unless you are sawing only short logs -- in the 8' range.

I've sawn a bit of Western Larch with mixed results. It's very straight with not much taper so recoveries are about the same or better than Douglas-Fir. On the other hand, if you hit a pitch pocket and you're not pumping the blade lube, the blade will dive abruptly and ruining a good timber. I also discovered (fortunately not with my wood) that a decent looking Larch timber can blow apart along the growth rings as it dries.


Bruce    LT40HDG28 bandsaw
"Complex problems have simple, easy to understand wrong answers."

longtime lurker

Scaled or unscaled Bruce? Either way I'm jealous - we sit around 35% recovery in Eucalyptus species.
The quickest way to make a million dollars with a sawmill is to start with two million.

Rougespear

If my math is right, there are about 450 "legit" bf per cube.  I think my yields were similar to Bruce's... in the 300 department.  His records are way more comprehensive than mine (I have none), but I may gamble and say I was getting more in the 350-375 department.  These were No1 and 2 d-fir @ 51'.  My yield may have been slightly higher as I was sawing for everything.

My advise though, estimate conservatively when pricing the job... unless you really need to money/or the job leads to future work.
Custom built Cook's-style hydraulic bandmill.

longtime lurker

I went back and edited my previous post with Doyle scale volumes added.

You really can't compare recovery off scaled logs with recovery from unscaled logs bought by the cubic meter or ton or similar. Unscaled logs you pay for the trash as well, and while you would process that volume either way its not possible to just convert cube to BF volumes and say I'm going to get x% recovery.
It don't work that way.
Unscaled logs have to be cheaper because you are paying for the saw kerf and taper and yeild reduction around a bend as well.
The quickest way to make a million dollars with a sawmill is to start with two million.

Bigshooter

So if logs are not scaled then you would have to get them at a reduced price per meter to compensate for loss.

Brucer

Logs in BC are sold by the cubic metre of sound wood. The logs have to be scaled, and there is a specific formula that is applied -- (area of small end + area of top end)/2 x length. Deductions are made for unsound wood and missing wood, but not for sweep, pistol grip, etc. Instead, wood that is considered to be "not recoverable" is used to calculate the grade of the log.

My numbers are based on overall recovery from 650 cubic metres of high quality logs -- no shake, no decay, only a small amount of sweep, and large enough and long enough to allow for efficient utilization of the log. I 've had higher numbers from very large logs, and lower numbers when I didn't have the orders to make the best use of the logs I had available.

I would have had higher recoveries if I had the time and space to increase my range of sizes. For example, I only stocked 3 widths and 3 lengths of 1x lumber. If I wanted to cut (and stack and sticker) 1x2's I'd have had higher numbers. If I wanted to cut (and stack and sticker) 6' long boards, I'd have had higher numbers. But there was not a big demand for those sizes so the eventual income (maybe) did not justify sawing them to put into stock. If I had a specific order for those sizes I would saw them and my recoveries were higher.

I made it a point not to have any wane on my wood. That earned me a lot of repeat business and also a lot of word-of-mouth business. People would pay me higher prices just because they could tell the product was better then what the stores would sell. If I'd allowed wane (but still within the Canadian grading standards), I could have had higher recoveries.

My recoveries began to increase slightly in the last couple of years after I discovered that there was a respectable market for "junk wood". In my case, that was anything with too much wane, or heavy checks, or log handling damage (or tapered pieces from forgetting to lower a toeboard :-[). People would often come by looking for cheap wood for things like temporary fences, batter boards, even a "jail house" for our annual fall fair. I'd show them my cheapest wood -- 8' 1x4's -- and they'd say it was too good. So I started saving the rejects and selling them for "half price". I never managed to get more than half a pile (250 BF) -- it turned out to be a steady mover.

So, yes, you can do better than 300 BF per cubic metre if it's worth your time and effort to make a large variety of sale-able products.
Bruce    LT40HDG28 bandsaw
"Complex problems have simple, easy to understand wrong answers."

DGK

I just had a load of logs scaled by our government forestry department. The conversion that was determined by stick scaling each log (small logs approximately 12" tops and less with 1/2" of taper per 4' in 12' & 16' lengths) is 200 bf per m3. Often the recovery over and above the scale runs 10-20 percent.

Edit. I should add that I use the International 1/4" scale.
Doug
Yukon, Canada

LT40G38 modified to dual pumped hydraulic plus, HR120 Resaw, EG200 Edger, Bobcat S185,Bobcat S590, Logosol PH260M3, Sthil MS660's, MS460,MS362's MS260, Trailtech dump trailer, F350, F700 Tilt-Deck log/Lumber Hauler, JD440B Skidder, Naarva S23C Processor

Bigshooter

Brucer, thank you very much for the info. You are a wealth of info!

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