4 bands for one log

[JoshNZ]

I went through four blades slabbing this log into 6 slabs yesterday (7 cuts), and I didn't hit anything! Just general wear. It's about on par with the band life I see while sawing these logs but I guess I have to ask the question, other than not having kerf clearing saw is there anything I could be doing wrong? Have you ever sawed any of the acacia woods and seen them gobble your blades up? This is acacia melanoxylon which grows all over the place here. Pretty stuff. Have also tried acacia mearnsii with the same results, one band per log milling. Brand new/resharpened or otherwise. They're 4 degrees, sets are a bit hit and miss, brand new ones have correct set obviously.

The log was 4m/13ft long, 35" at the wide end maybe 26" at the small end, bit dirty on the outside but not terrible, I did a bit of wire brush work. In the guts of a log I could have swapped bands after each cut, but squeezed out two slowing down for the second half of the second one.

I had a blade dive at one point, I was able to back up and feed again slowly and it cut out of its dived track and carried on straight. Can't believe I got away with that. But I thought it was unusual. Can't see anything anywhere that I've hit.

Im estimating they're about 320kg/700lb each, I can't even lift one end by myself haha. A real nuisance to handle, all clumsy forklift work. The effect they have on a space is amazing though I think it's worth it.

Anyway back to my question.. 4 bands for 7 cuts..? It's still worth my time and effort but it seems excessive. Would I try increasing the rake from 4 degrees?



 

 

 

 

Different log of same species finished up a while back.


 

[WV Sawmiller]

  Pretty wood! You don't mention hp (May be in profile below) or hook angle but I'd certainly try 4* blades if you are using anything bigger. Good luck.

[JoshNZ]

22hp, 4 degree blades

[Magicman]

bit dirty on the outside but not terrible, I did a bit of wire brush work.

Of course I have never sawn your species, but a bit dirty is sorta like being a bit pregnant.  Dirt dulls blades.  ;D

[moodnacreek]

Is that hardwood, it looks like cedar to me and some cedar has a grit in it that will chip carbide.

[barbender]

Maybe @longtime lurker could answer this- aren't a lot of your hardwood species down there pretty abrasive, as in the wood itself? Maybe a bi-metal or carbide band would serve you better for those.

[Southside]

Sounds like a catch 22 and you are doing the best you can with what you have.  Lower HP, very hard wood, means you have to advance slowly, which builds up heat and causes teeth to loose their hardening, so they dull quicker.  Not many options aside from maybe a carbide as was suggested. 

[Ianab]

Is that hardwood, it looks like cedar to me and some cedar has a grit in it that will chip carbide.

It's a hardwood, closely related to Koa. Saws OK with the swing mill, but it does seem pretty hard and dulling when working with it dry. I suspect that it needs a perfectly sharp blade, but dulls them fast?
But if you think that's hard, keep away from Sheoak :D

[JoshNZ]

Needs a perfectly sharp blade which isn't sharp enough by the second cut, apparently haha.

It is hard on the planer too yeah, groans away and doesn't last long. I ordered a carbide helical head, arriving next month I hope.

I think there's a bit more going on here than dirty logs but I know it doesn't help. I really should build a debarker for it

[btulloh]

While you're waiting to build your debarker you can just take a strip off by hand along the cut line. Axe, hatchet, bark spud, etc.  it's amazing how fast a little grit in the bark, plus a hard wood, and relatively low hp can dull a blade.  Wood like that really needs a sharp edge. Looks beautiful though, and worth the effort. 

[Satamax]

JoshNZ, what are you lubricating with? 

I use a mix of diesel, washing up liquid and water. I make a mix 1/3rd washing up liquid, 2/3rd diesel. And mix that 1/3rd-2/3rd with water. 

It stinks. Not too ecological. 

But it could work. 

Drenching your cuts with it. 

Just an idea. 

[JoshNZ]

I'm just using straight diesel.

Probably could've run a bit more for this stuff.

The answer I'm hearing is, build a bigger mill with an engine twice the size?

[longtime lurker]

Blackwood?  It grows up here but quite uncommon, but we do a lot of Acaccia aulacocarpa which is pretty much identical. Yah, not fun... It's not hard hard but if it's in sandy soils (around here at least) either will suck up silica.

Bark it all you want, it's hard to keep saws sharp when the sand is on the inside. It dulls tungsten carbide teeth pretty quick, back in the days of spring set saws they avoided it as too dirty/ easier things to cut.

Dunno how to achieve this with a band mill but with circle saws you grind off the chip breakers and feed faster. Bigger chip are less likely to escape the gullets and less recutting of the chip means the edge doesn't work so hard and holds up longer. Powdery sawdust means the chip is getting recut and it dulls the edge each time it contacts. Deeper gullets on the bands maybe?

[thecfarm]

That sure is pretty!!!

[JoshNZ]

Blackwood yup, I should've mentioned that.

I wondered about silica too, I've turned walnut that I figured must've been sucking on sand soils I couldn't believe how quick my chisels dulled.

I'll soldier on with plenty of sharp blades and keep the feed up.
I haven't got many of them left.

I've got another one out in the staff room, both this and the one on the forks above are a bit of an experiment, finished only 3 months after milling but they've behaved nicely.



 

 

[longtime lurker]

per Bootle: "Easy to dry, with little checking and negligible collapse. Shrinkage about 1.5 per cent radial, 4 per cent tangential" (That would be shrinkage to 10% MC in line with Australian industry practice)

Tough on saws and planer blades, but it doesn't warp or twist "much" even if the log has spiral grain in my experience. You guys are I think like here... quite humid. EMC here is 15% but fluctuates between about 13-17% seasonally. I've always figured that if shrinkage is 4% to 10%MC, then it's gotta be about 2% to 15% MC... and 2% is nothing, most everything made of wood shifts that much here seasonally anyway.

[Satamax]

I'm just using straight diesel.

Probably could've run a bit more for this stuff.

The answer I'm hearing is, build a bigger mill with an engine twice the size?

May be try my recipe, and flood it. 
As for the mill, looking at what you are cutting, may be it would be clever to go bigger! :D 
One thing which hasn't been said, stellite bands seem to withstand dirty wood better. 
And i have read in a very old leaflet from the manufacturer of my mill, that Swaged teeth were doing better into African hardwood, than set teeth. May be another path to explore. 

[JoshNZ]

Does the dish soap allow the water and diesel to mix, is that the idea?

Any time I've checked for water in diesel and found it I've definitely not thought to myself that seperated solution would make good band lube xD.

[Satamax]

Does the dish soap allow the water and diesel to mix, is that the idea?

Any time I've checked for water in diesel and found it I've definitely not thought to myself that seperated solution would make good band lube xD.

Yep JoshNZ, that is the idea. Make an emulsion of diesel, dish soap and water. I don't claim it to be far better. But it cleans the parts somewhat, cools the blade, cleans it too, prevents it from rusting as much as just dish soap and water. Saves a bit of diesel. So you can really flood your cuts. I was using that "lubricant" as cutting oil on the lathe, before i could afford a coolant pump. 
Mind you, i don't have a whole lot of experience, my saw is up and running since august 2016
And i might have 20 trees a year cut on that one at absolute maximum. 99.9% of the time it is larch. 0.1% of the time, it has been ash. 
So you know what i'm talking about. 
Samill cable follower 2 - YouTube

[wisconsitom]

Hi Satamax.  Wondering, would the larch be quite resinous and sappy while sawing...and does your liquid mix help keep blade, etc. clean?  Reason I ask is if I ever get a saw, it will be to make stuff out of larch I have growing on my property.  Somewhere along the way, I'd heard that larch can be a bit challenging to saw in that regard, but I've also read accounts of great ease of sawing.

Dries slowly too, I believe.

[barbender]

Eastern Larch can saw great, or horrible. The sketchy conditions it grows in can lead to very twisted grain etc. I've learned to pick which ones go on the saw, or straight to the firewood pile. I just git back from northwest Montana, and U was drooling over that Western Larch. Straight, no taper, just beautiful timber that I suspect would all saw well. All of that said, Larch is the worst wood I've sawn for pitch build up on the blade. As far as drying, it is the one softwood I think were you should try to slow the drying process. I've seen it crack across the grain from stress, in a stickered pile. Again, this is eastern larch we call tamarack, and I would expect other larch species to behave better due to their better form if nothing else. 

[wisconsitom]

Thanks Barbender.  I've got tamaracks present in my woods, but what I'm contemplating here would all be hybrid larch.  Largely growing straight and tall.

I do wonder if I'll ever get so far as to have a saw rig.  Or will I go up the road a few miles and see if that commercial sawmill in town can do anything with my logs.  We're thinning in those blocks already, but so far, not saw-sized materials, just poles and posts.

Gotta plan ahead though-fast growers!

[Satamax]

Hi Winsconsintom. Larch gums the blades. Even with diswashing liquid. A friend of mine, with the sawmill in the next village, and the same type of mill as mine. Cuts a pine every three of four larches, to clean bladesIt dries fast here, where it's always fairly dry. Average 30/35% rh in the air iirc. In three or four months you can use a 1 inch thick board. I forgot to say, mountain, larch is tempéramental and dries often crooked if not strapped.


Check that LE SECHAGE DU BOIS

If ever your google is keen on translating. It' s an interesting read.

[wisconsitom]

Thank you sir.  That's not a light read!

[longtime lurker]

That is an interesting read. Not that I've finished it but I made it down a couple pages and I'll finish the rest later.

I note that the old French air drying rule of thumb was 1 centimetre per year. Here it was an inch a year, so 2.5 centimetres, presumably from some old English rule of thumb. I find that interesting, given that species would be identical and wonder at the why of it.

The other being that I have some customers who do fine furniture who don't want KD wood, and will pay a premium for air seasoned. "More workable" is the usual comment, and all the explanations about modern kiln controls vs the older types do not make much difference. Thing being that I do believe they are right, my limited experiments with hand planes and chisels seem to agree with them... air dried wood feels softer than KD.

None of which gets around the reality that sitting on a stack of wood for years to season it comes at a price, and in our world of just in time delivery it's not an economically viable proposition