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General Forestry => Sawmills and Milling => Topic started by: shinnlinger on July 30, 2020, 09:17:59 AM

Title: Old bands or band tension?
Post by: shinnlinger on July 30, 2020, 09:17:59 AM
Hello, 

I have a 15 yo Turner trailer tire bandmill that I did a lot of work with years ago.  Milled my house as  a bunch of other stuff.  Probably 30kbdft worth.   But in recent years it mostly sat but this summer my 17yo daughter decided to move out and started building a tiny house.   We tuned up the mill and it runs great.   Our problem is the wavy cut issue and I know that’s typically dull bands but I have a pile of bands from back in the day and I think most  were sharp but are now rusty from sitting.  I can usually tell by feeling/inspecting but any pointers there?   Should I just buy new ones?
Also band  tension.  I used to fire up the mill and crank the tighten bolt until the band stopped flapping with good results but maybe my technique could use refinement?  

Thanks 

Dave
Title: Re: Old bands or band tension?
Post by: farmfromkansas on July 30, 2020, 10:03:33 AM
How are the tires on the old mill?  No experience with rubber tire mill, heard Turner company no longer builds mills.  Do you have a book, wonder what the tire pressure should be?  You could send your bands to be sharpened, cheaper than new blades, Cooks will clean them up and sharpen them. Do you have a sharpener?
Title: Re: Old bands or band tension?
Post by: terrifictimbersllc on July 30, 2020, 10:34:18 AM
One can tell if a blade is sharp by looking at the tips with a 10x hand lens. Rust will come off when sawing.
Title: Re: Old bands or band tension?
Post by: trimguy on July 30, 2020, 12:41:35 PM
The rust will cause drag and cause problems. The mill I built was a rubber tire mill and that is how I tensioned the blade, but I would always give it “ a little more “.
Title: Re: Old bands or band tension?
Post by: Den-Den on July 30, 2020, 05:42:50 PM
My mill uses tires, on mine the tire pressure needs to be right for the tracking to be right.  Wavy cuts on my set-up is caused by dull blade, not enough set or sap build-up.  Extra tension may delay the problem for a cut or two but that is all.  Any rust is usually worn off in the first cut but I have not tried any blades with heavy rust.  If I had some rusty blades, I would set the teeth and sharpen before using them.
Title: Re: Old bands or band tension?
Post by: Wintergreen Mountain on July 30, 2020, 06:23:12 PM

   I have a Turner Mill.

 I run tire pressures at 36lb.

Make sure the guide bearings are turning free . Back, Top and bottom.
 If they sat for years they are no good.

Top and bottom bearings are 
6301 2RS-10
Back bearings are VV300

Adjust the guide top and bottom bearings to align  blade with the deck.

Blade tension.  Adjust to take the limp  out, than adjust the screw 1 1/2 inch more. This will put about 8-9000 lbs tension on the band blade.

Hope this will help you.

Leon
Title: Re: Old bands or band tension?
Post by: Stephen1 on July 30, 2020, 07:59:06 PM
I would say the blades are dull if they have rust on the teeth into the gullet. If the blades are pitted then new blades will definitly help .Surface rust will rub off as you saw. 
Title: Re: Old bands or band tension?
Post by: Iwawoodwork on July 30, 2020, 11:59:52 PM
I got some dull blades  (6-8) with my saw when purchased, They have surface rust on them, I got one out today and sharpened it with a Dremel using a 3/8" diameter stone just touching up the face/tip an very little of the gullet and it seemed to cut ok for this newbe wood butcher, was cutting Juniper which is like cedar.  Kbeitz wrote about sharpening his bands this way with good results so I decided to try it.    You have nothing to loose sharpening up and trying some of those old bands.
Title: Re: Old bands or band tension?
Post by: YellowHammer on July 31, 2020, 08:54:14 AM
Rust is caused by the metal oxidizing, and if there is rust on the band then the cutting edge and chisel corners, which really need to be sharp, have turned into rust also, and “gone away.”    

New or freshly sharpened bands are always a good idea for troubleshooting a mill. 

I notice a decrease of cutting ability if I simply leave a sharp band on the mill and come back to it a couple days later.  

 
Title: Re: Old bands or band tension?
Post by: Walnut Beast on July 31, 2020, 02:46:58 PM
So your saying a slight surface rust can make a difference after a couple days. What if you took it off and wiped it down with a scotchbrite in oily residue and put back on 🤔
Title: Re: Old bands or band tension?
Post by: Wintergreen Mountain on July 31, 2020, 05:16:16 PM
    I think WalnutBeast is referring more to the rusting and possible pitting and damage to the sharp tip of the hook. The tip is very thin and can be rust dulled very fast.
    I have experienced this phenomenon my self. 

   Leon
Title: Re: Old bands or band tension?
Post by: Wintergreen Mountain on July 31, 2020, 05:20:54 PM
   I meant to help answerer YelowHamer with My last post. Not Walnut Beast. 
   Leon 
Title: Re: Old bands or band tension?
Post by: YellowHammer on July 31, 2020, 08:19:17 PM
Correct, a light or general surface dusting of rust on the main body of a band doesn’t seem to be that big of a deal, it scrapes off the first cut or two.  However, the super sharp teeth edges of the band, the chisel edge and the tips of the teeth corners, are by their nature, very thin and don’t have much metal to loose.  So when they rust, even slightly, the metal that makes them sharp, scrapes off.  So the tips go from razor sharp, to duller, in a short period of time.  Maybe not dull, but certainly duller.  
 
The sharper the cutting surface, the thinner the metal is at that point, and the more the effect of oxidation will have on overall sharpness.

Basically, if I turn the mill off in the evening, leave the still sharp band on, and come out the next day and restart sawing, there is no problem.  If I leave the band on over the weekend, and restart sawing on Monday, I have a noticeably duller band.  Sometimes I just go with it, sometimes I will swap it out.

Here’s a magnified picture of a sharp tooth.  Notice how thin the cutting surfaces and cutting corners are.  Just like the edge of a woodwork chisel.  Now imagine what rust would do to the edge of a razor sharp knife, a woodworker’s chisel, or bandsaw tooth.  


(https://forestryforum.com/gallery/albums/userpics/21488/image~45.jpg?easyrotate_cache=1396324957)
 





Title: Re: Old bands or band tension?
Post by: Walnut Beast on August 01, 2020, 12:04:21 AM
Very nice insight YellowHammer. I will definitely keep that in mind 👍
Title: Re: Old bands or band tension?
Post by: Wintergreen Mountain on August 15, 2020, 05:37:01 PM
     shinnlinger (https://forestryforum.com/board/index.php?action=profile;u=6762)

    Have you got your old Turner Mill operating again yet, and if so how is it sawing?