Band life survey

[Ron Wenrich]

I was talking with a guy about band saws, and he wanted more info on how band saws hold up.  I don't have much experience with them, so I figured its best to go to the guys who use them all the time.  I also know there are a lot of variables between operations.  I'm just looking for your average numbers. 

1)  What is the average volume you get per sharpening?
2)  How many sharpenings do you get per blade?
3)  Avg cost per sharpening?
4)  Do you saw logs with the bark on or off?
5)  What are the primary species?
6)  What's the primary product (dimension, grade, blocking, custom)?

Thanks in advance to anyone who wishes to participate.

[Magicman]

On a recent framing lumber job, I averaged over 1500 bf per band and changed bands at each startup, not when it appeared dull.

I never try to saw over ½ day with a band.  When I stop for lunch, etc. it gets a fresh band.  Sometimes with knotty or dirty logs, I may not make it that long.  Sometimes 300-500 bf.  I believe that blade life is extended by changing them before they dull.  I know that the lumber quality diminishes if you try to push a band.  Everyone loses.

I use ReSharp, and if bands don't break, they replace them when they get too thin.  I would think 6-8 sharpenings.  I don't keep a record of individual bands and a box of 10 cost $104 to sharpen.

Most of my sawing is SYP and a majority of it has slipped bark.  I open the face according to the log, not the dirt, which sometimes makes the Debarker earn it's keep.  My next job is freshly felled and skidded Cherrybark Oak and it is very dirty.

SYP is used mainly for framing lumber and is sawed factory dimension.  Other species are used for siding and paneling and mostly sawed 1".  I saw very little for furniture builders

[Tom]

My experiences are aging, but here is what I found.

1)  What is the average volume you get per sharpening?
This is dependent upon the species of wood, and highly dependent upon the horsepower of the saw.  The band configuration doesn't change and the higher horsepower can take advantage of more of efficiencies of the band design than a lower horsepower mill.

Usually those mills in the 15 horse or less range can look forward to 200 to 500 bf per sharpening.  Those of 20 to 40 horse may work within a range of 600 to 1000 feet per sharpening.  Eventually the design of the band is maxed out  and somewhere, in the 50 or 60 horse range that happens for 1 1/4 or 1 1/2 bands.  It doesn't stop the mill from producing more board feet though, because the extra horsepower allows faster and greater log-handling capabilities.

2)  How many sharpenings do you get per blade?
I would get three to six sharpenings before the band would break from work-hardening. It is highly variable though and a lot depends on the species of wood being sawed and the aggressiveness of the sawyer.  It's dependent on the horsepower of the saw and it also depends on how anal the sawyer is about having a sharp band.  I've seen some tout many sharpenings only to find that they are not working the band to its optimum.  If you sharpen a band over and over and only cut 5 boards per, you can get a lot of sharpenings.  Number of sharpenings is a faulty way of judging production.  A better way might be #number of board feet produced per band.

3)  Avg cost per sharpening?
With me, it was difficult to measure. I sharpened my own and where sometimes I could assign an hourly wage, sometimes it was a pleasure to do and an excuse to not be in the house.  Sharpening ones own bands gives you the opportunity to "Fix" teeth that have found tramp metal and also allow the use of bands that normally would be cast aside by a commercial sharpener.  I could set about 5-6 bands and sharpen 3-4 bands per hour, so a three hour sharpening period would produce about 10 bands and a handful of set bands with which to start the next session.

4)  Do you saw logs with the bark on or off?
I sawed with the bark on.  If there was a lot of dirt, I manually debarked a path for the saw. My latest saw has a debarker-saw that does just that but I haven't a lot of experience with it.

5)  What are the primary species?
I would tell customers that I sawed any wood with roots. But the primary woods were Yellow Pine, Cypress, Black gum, Sweet Gum, Hickory(s), Sweet Bay Magnolia and followed by many other southern species in lessor quantities.  There is a thread on the forum somewhere, where we listed the species we had sawed.

6)  What's the primary product (dimension, grade, blocking, custom)?
I sawed mostly for farmers and backyard cabinet makers, so my repertoire was mostly 4/4 x 6-12 and a lot of 2x4 or 2x6.  Occasionally I would get into a fix of having to saw a lot of 1x3 or 1x4 and sometimes I got to saw 12x12.

My cabinet maker customers favored 8-12 foot lengths and my farmer customers wanted 16' and above.  When they find that you can saw 20' or longer they are ecstatic.  Being able to cut longer than 20' was instrumental in the purchase of my last sawmill.

[WDH]

On my LT15, I get about 600 BF per band, but I wash the dirt off the logs before sawing. 

Most of mine had had 4 sharpenings, but a few went only three.  I am not high volume, though, so I do not have much data.

I use Woodmizer Re-Sharp, so about $8 - 9/blade.

Bark on, put sprayed with a nozzle to remove obvious dirt.

Hardwood.  Walnut, cherry, maple, yellow poplar, and oak, mostly red.  Some sycamore, sweetgum, osage, chinaberry, red cedar, and pecan.  Very little pine.

Mostly 4/4 with some 8/4, 8.5 feet to 10.5 feet in length.

[Bibbyman]

How many board feet/blade?

I'd say an average of 500.  Like Tom said, it's highly variable for all the reasons he gave.  We use 1-1/4 x .045 blades.  If we were to step up to 1-1/2 by .055,  we could push them longer.  Also, we've learned to change a blade when it starts to get dull – not after.   

This afternoon we were sawing with a blade we'd used quite a bit.  Time to change.  Put on a new blade and sawed one large, dry white oak log then squared down another.  It started to make wavy cuts over the hard knots.  I suspect we hit some grit.  But we only got a couple hundred (one large log) out of that blade.  Then again, it was tough sawing.  If we were sawing smaller, fresh logs, we could have kept using it.

How many sharpening per blade?

When we sent them to Re-Sharp, we would get maybe 4-5.  Now that we are using our own equipment, we can get many more.  Maybe more than wise.  The blades get very narrow and lose their beam strength.  Thicker blades will break well before thinner blades.

Average cost per sharpening?

Resharp cost a little less than $10/blade with shipping.  It pretty much took me all day to sharpen 20 blades on our equipment.  So I avoided spending $200.00.  But I also avoided making money by sawing.  The only way I can justify sharpening our own blades is to do it when I can't saw.  $5000.00 + in equipment and a little for supplies (oil depletion).   I'm a long way from break even.

Bark on or off?

We saw with the bark on – unless the logs are old and the bark falls off.  Our mill has a debarker and that helps but does not always get the occasional flint rock that is driven in.  Thick, soft bark line on walnut is the worst.

We primarily saw oak.

About half of what we produce is 4/4 flooring lumber – followed by cants and beams.  About 10% is custom sawing of mixed species.

Other input:

We've visited quite a bit with a guy that has an LT300 mill.  He has a debarker on the lot and all logs are debarked before being placed on the infeed.  He saws mostly oak with the balance other hardwood.  He says they saw 8/mbf per day.  He uses the WM 1-1/2" x .055 Doublehards.  He says he changes blades and noon break and at end of day.  That would be 4,000 bf per blade.  I find that hard to believe.  I'm sure there are times when a blade just gets dull.  He was sending the blades back to Resharp one time and then discarding them.  After a second sharpening, they were likely to break.  Breaks caused production shutdowns so it was not worth it to try for the second re-sharpening.

[ladylake]

1   Around 350 bf in WO and ash, way more in easy wood
2   Up to 20 now, some are down to 1" wide and I take off around .012 per sharpening, I used to get 5 or 6 sharpenings before putting on a good chip deflector.
3  Just time 7 -8 minutes and a stone once in while plus the sharpener cost, I'd guess about $1 per blade
4 Bark on, try not to cut through the dirt
5 WO, white ash , red oak ,basswood, pine
6 Most anything

[customsawyer]

I have only a few things to add that has not been said.
If I am cutting the 12X12 timbers out of logs that are fresh then I tend to get between 2000 and 2500 bf per sharpening. If the logs are a little older then the production per sharpening goes down.
If I am cutting cypress I have cut all day with one blade.
I have a 55 hp diesel and run a 1 3/4" X .055 blade most times.
The blades that I get the higher production per sharpening I get fewer sharpenings per blade.
The bottom line is that my blade cost run pretty close to .008 cents per bf.

[TLahti]

Hi Guys: Great survey topic.
      I have 5 1/2 HP (don't laugh, it works great) Woodwizard (not Mizer) push mill that uses 1 1/4 x .042 blades.
I am starting my second year of milling, and I am cutting red pine for personal use. I have a hard time judging when the blade is dull, so I mounted a manual counter on the frame where I can move it one click each time I make a cut.
    The first time I used the counter, I went 60 cuts and I could tell the blade was dull, so I started going about 45 cuts, then sharpening. Lately, I have been going 35 cuts then sharpening.
     I have determined that it takes roughly 12 cuts per 50 board feet, so I am getting about 150 BF.
   I have a manual sharpener that grinds the edge of the tooth, and it takes me about 20-25 min. I sharpen very shallow, to make the blade last. I have never had a new blade, I got used ones with the machine.
   If I was paying $10 per sharpening, it would be costing me 28 cents per cut, or about 7 cents per board foot.    Terry

[backwoods sawyer]

If only all the nails and rocks would wait till noon and the end on the day to show up I would only use 2 blades a day, but I do not like to pull out of the drive with out at least half dozen saws in the truck. I just spent the weekend sharpening 30 saws and 22 of them had hit something. I engrave a number on each saw and track the life of each saw. I retired one saw out of the batch this time around and it had hit metal six times and had produced 10,000 bft over its life of 19 sharpening. It was .055, 1 ½", 13* double hard woodmizer saw which has the deeper gullet for softwoods. Matching the saw to the wood that you are cutting is one of the keys. I had one batch of saws that I had not dressed the stone properly and the hook angle got changed, that was on the 6th sharpening, and they are now used for logs that I know there is metal in.

Two of the local mills only send their saw out to be sharpened once, and then throw them away. I got a dozen used saws from one of them and found that it was not worth the time I spent trying to get them back to where they would cut consistently. Made good saws for those metal logs but I have enough of my own saws for that.     

[Chuck White]

I also know there are a lot of variables between operations.  I'm just looking for your average numbers. 
Thanks in advance to anyone who wishes to participate.

1)  What is the average volume you get per sharpening?
      500 - 8/900 board ft     
2)  How many sharpenings do you get per blade?
      6, sometimes even 8.
3)  Avg cost per sharpening?
     Sharpen my own.  1 grind stone/rock will do around 100 sharpenings at a cost of $18.00 per grind stone/rock.
4)  Do you saw logs with the bark on or off?
     Bark on.
5)  What are the primary species?
     2/3 White Pine and 1/3 Hemlock, with a little hardwood (oak, maple, cherry) mixed in here and there.
6) What's the primary product (dimension, grade, blocking, custom)?
      Custom, 2x4,6,8,10,12  1x4,6,8,10,12  a few posts/beams 4x4,6x6 & 8x8

[sgschwend]

When I ran the bandmill, mostly Douglas Fir.

DF seems to take it out of a saw.  In a given day four saws would be used to cut between 5-8 hours.  Which would produce between 1500 and 2200 bf.  The main factor seems to the the amount of cutting through the bark.

To mitigate this issue I started rotating the log so that the second cut could enter clear wood and exit the bark.  Without this method there were times that the saw would be dull after cutting through the bark four times.

[postville]

Just getting started with this, but so far-

1-Getting 1200 bf per blade. Using Cooks 8 degree, sawing 8 foot basswood, winter cut, clean, bark on, 1 1/8th flitch cut.
2- Have sharpened three times so far with a chainsaw type grinder. Thanks all for the tips, grinding the back was important.

[buildthisfixthat]

i use 14 foot long 1-1/4 blades 0.42  on one of my blades only cut about 300 bdft  of hard ash before it distorted took it off the saw and it lays in a figure 8 pattern ,it did cut nice for 300 bdft though ......it appears that a blade that cost 25.00 only last half as long as a fifty dollar blade

[buildthisfixthat]

oh yea cost for sharpen is 12.00 ...saw with bark on........i saw ash ,cherry and pine mostly ....saw 1" boards 6 to 30"wide though with the 1-1/4 blade any cuts wider than 20 inches will most likely be wavey

[woodmills1]

let me say first, having only yard trees to deal with metal is the ban of my existance



OK talking no metal  just cutss......I use woodmizer 7 degree and have older shapen and set

1)  What is the average volume you get per sharpening?

most give me 500 and above.  as said if I take them off sooner more life, but they hit metal already

2)  How many sharpenings do you get per blade?

most ever 11 no metal 3 sets

3)  Avg cost per sharpening?

free except for time but the package I have was over 3 grand new but I got it with the 15k first mill LT40


4)  Do you saw logs with the bark on or off?

used to bark on now the 70 has the nice debarker

5)  What are the primary species?

pine and oak

6)  What's the primary product (dimension, grade, blocking, custom)?

1 1/16 high school shop wood

4/4 dunnage

1x6x16 oak horse fence

2 by trailer deck and truck boards