The Forestry Forum

Sponsor News => Turbosawmill => Topic started by: NZJake on November 27, 2016, 08:19:47 PM

Title: Circular sawyers!
Post by: NZJake on November 27, 2016, 08:19:47 PM
Hi Guys,

Here at Turbosawmill we are putting together a knowledge base of sorts.

I'm in need of your experience. We would love to get some user feed back on just how your circular saw reacts to the many species of trees you have come up against. I'd like to collate what you have learned into a tool we can all benefit from.

I just want to know how your circular saw reacts and performs in each species. Do you need an extra sharp blade, more water than usual, do you have to proceed very slow through the bark? Significant pitch build up? Lots of tight knots? Does the bark and dust cause problems? Do you have to take in half cuts? The more you share the better the picture.
Bandsaw guys... I'm not trying to leave you out but the two styles of machines perform very differently in the same species of log.
Title: Re: Circular sawyers!
Post by: ddcuning on November 27, 2016, 08:44:04 PM
Well I just started sawing on my mill in June so I haven't had a lot of species. So far, I have sawed southern yellow pine, tulip poplar, white oak and hickory. The results were as follows:

SYP - The saw cut it like it was butter. Made perfect dimensional lumber. No pitch build up, could saw fairly quickly, no problem with dust.

Tulip Poplar - Same as the pine, cuts like butter and makes perfect lumber.

White Oak - had to cut a little slower. Made pretty good dimensional lumber but on occasion, if I got to fast, I sawed a slight wedge. It has also been a year since I aligned my mill and that is on my to do list so it could be I am out of alignment a little.

Hickory - I have sawed hickory two first and my last. Within three board (1-1/2"x10"x7'long) the teeth were dull. Managed to saw three 7' logs and had to shut down and sharpen. Had the blade get warm after every couple of boards and had to wait for it to cool to keep going. Again, some of this may be due to the fact that I haven't aligned my saw since last year but some of it is the fact that hickory is just darned hard. From a dimensions standpoint, the hickory did much like the oak, made good dimensional lumber except on occasion it sawed a slight wedge.

Dave C
Title: Re: Circular sawyers!
Post by: NZJake on November 27, 2016, 09:30:59 PM
Thanks for the feed back. Good to know about Hickory. Would love to know more. Is it harder to saw through the sap region? Whats the core like? Is it furry which pushes the blade around?

Your worst case log would be ideal. Hickory is perfect!
Title: Re: Circular sawyers!
Post by: Ron Wenrich on November 27, 2016, 10:11:06 PM
I've had logs of various species that sawed good, and others not so good.  A lot of guys have problems with hickory, but my experience has been that some logs saw great, while others are hard.  Saw sharpness has a lot to do with it.  The other thing is that guys tend to slow down while cutting it.  Its usually the saw sharpness that causes them to slow down.  The slower speed causes smaller dust which tends to spill out of the gullets and causes heat.

I've had beech that has caused problems.  They were probably worse than hickory.  Not due to hardness, but it just wouldn't saw well.  In many instances I would come out thinking that the problem might be with the log.  I have found that often the next log would clear up and saw well.  That's when I knew it was in the log.  If it doesn't clear up, then it is usually in the saw.

To clear up the saw problems, you need to stop and sharpen.  If that doesn't clear it up, you might need an adjustment in the saw guides.  Some species needed a bit tighter guide than other species.  Sometimes you need more lead.   Before fooling with the lead, I would change teeth.  That takes away all of my filing mistakes and helps me troubleshoot. 

The worst logs to saw are those that are half frozen.  You will get it when the weather gets cold enough to freeze, but not cold enough to freeze all the way through.  The other time is when the frost come out.  Logs laying on the ground will always be frozen on the bottom at that time of year.  Always a tough time sawing them. 

You're sawing through 2 types of wood - frozen and thawed.  If you have any spillage from you gullets, its going to freeze to the log as you cut.  That will push the saw, cause heat, and you're pretty well done sawing.  Your problems usually go away when the wood is frozen.  I also would make my teeth narrower and cut back the lead, as dust from frozen logs is finer. 

Other problems I've seen other circle sawyers have is feeding too fast.  The saw bogs down and lays over, which opens up the saw and causes heat.  Some wood will let you saw as fast as you want, others won't.  But, its a combination of log hardness, saw sharpness and feed speed. 
Title: Re: Circular sawyers!
Post by: NZJake on November 28, 2016, 12:13:27 AM
Hi Ron,

I guess what I'm after is the unique characteristics of each species of timber. A circular saw is very robust and an efficient operation when the teeth are sharp, lots of clearance and water. I am assuming all this is correct and would like to I guess give the new sawyer some idea as to what they would expect out of each scenario.

Based on my experience here are some observations:

Redwood. Extremely easy to saw - once you get passed the VERY thick bark. Bark seems to go every where and wrap around things. I've found that its very quick to cut but sawyer beware... without water your blade can heat up very quick due to the blades ability to float in the soft timber when over fed.

Australian Eucalypt. Generally speaking full of tension (older the log the better it is). You need to wedge a lot of the boards as they are being cut otherwise the tension will bind against your blade. Motor will bog down and heat up the blade. Water is very important here too. Core can be boxed out or simply cut out and thrown away. Most tension logs will be back sawn due to the excessive crook produced. I actually like the harder timber as the blade seems to track much better than softwood.

Ceder/Spruce. Very easy to cut smaller boards. When sawing deeper cuts lots of water is needed as the timber is very furry (like a wire brush against your blade). Bark seems to go everywhere too.

Old man pine. Full of sap. Blade will need to be cleaned periodically.

Oak - you guys will be the expert. I come across a few species at the Paul Bunyan show. It all sawed well but there was significant differences between them. Wish I could remember the names...

Title: Re: Circular sawyers!
Post by: bandmiller2 on November 28, 2016, 07:22:10 AM
Good morning Jake, I assume your referring to circular saw on a swinger, not sure how they compare to say a 48" headsaw. Its not common practice where I am to put water on a circular saw. I have cut W. pine, oak, maple, ash, and cherry never had any pitch or buildup on the saw. The only difference I can tell is the power required for oak of all species. A diesel that will breeze through pine will be black smoking and on its knees if you don't slow the feed in a large oak. Bits with proper hook and vicious sharp corners is the answer. Perhaps the finer points escape me but other than the power requirements I've seen little difference between the species. Frank C.
Title: Re: Circular sawyers!
Post by: NZJake on November 28, 2016, 01:21:04 PM
Hi Frank,

Yea I guess I need to close the definition a little. I don't think the single saw fixed blade would react the same.

The swingmill usually has its blade tweaked to its near limits on kerf size and blade thickness in order to get the most performance out of it. So the differences can be a little more evident on them.

The bigger the tips, blade thickness and hp used the more forgiving things get. So unfortunately I think I have to redefine this thread to swingblade mill owners. Fair point.
Title: Re: Circular sawyers!
Post by: dgdrls on November 28, 2016, 09:51:55 PM
Hi Jake,

In my experience;
Ash can be tough and if you put a little water to it the dust/shavings will dry hard, 
Black Locust cuts well just get the bark off it first
Mixed experience with Walnut I have had a couple drier logs that sawed hard in an 8" cut others no problem.

Title: Re: Circular sawyers!
Post by: longtime lurker on November 29, 2016, 06:23:32 AM

Australian Red Cedar: soft and tends to be furry which can cause overheating problems in deeper cuts. Adding miscible spray oil to water tank improves this slightly due to lubricating effect. Increase side clearance angles on tooth. If volumes are sufficient for cost recovery add more gullets and use ATB tooth pattern.

Northern Silky Oak (Carwellia): cuts really well backsawn but requires slower cutting/ really sharp teeth on the quarter to prevent tear out.

Jitta: spring, spring , spring. saws will bind very quickly and unexpectedly even with wedging in place.

Queensland Black Walnut, Yellow Walnut (also Teak, Turpentine, Tea Tree, Paperbark and other species with high silica content): use stellite tips rather then TCT. Use higher feed speed (shallower cuts) rather then deep (slow) cuts as much as possible - the coarser the sawdust the longer between sharpenings.

Milky Pine (White Cheesewood) add diesel to water tank to reduce latex buildup on everything it touches.

Northern Cypress & White Cypress. Logs should be milled as fresh as possible and (if required) dressed/moulded immediately post milling to prevent splintering due to the brittle nature of the dried timber.

Red Bloodwood, Red Mahogany (also the portion of Morteon Bay Ash below the stocking and anything else with lots of kino) Kino build up on the saw best prevented by adding diesel to the water tank.

Ironbark: best to bark logs before sawing due to dulling effect on teeth.

Forest Red Gum: can have very steep density gradient around knots/patches of heavily interlocked grain in old growth material. Sawplate may deflect over/under/around these areas causing severe binding and loss of saw tension. Best to feed dead slow when there is evidence of a knot in the timber.

Grey Bloodwood. Very tight. Saw howls in the cut. Sawdust like powder.

Red bean, Miva Mahogany, Black Bean, Leichardt, various Fishtail Oaks, Grey Satinash, Crows Ash, Johnston River Teak, Yellow Carabeen: Don't breathe in the sawdust on the first two due to severe lung irritation, blood in urine etc etc - wear dustmask/ repirator. For all of these wash hands before eating/ smoking/ aiming urine - skin and /or nasal irritants.

Cooktown Ironwood, Georgina Gidgee. Safety precautions as per above plus remove any splinters promptly due to the highly toxic nature of the wood extractives.

Most of the rest I've sawn are just wood... some harder, some softer, some better, some worse.This is the stuff that stands out as requiring something out of the ordinary to handle

Title: Re: Circular sawyers!
Post by: NZJake on November 29, 2016, 11:20:41 PM
Long time lurker. That's exactly what I'm looking for! Thank you very much.

So I am putting together what I call 'swingblade APP'. It will include tools, converters, recovery calculators, adjusting, setup, safety, servicing, hints and tips, cut list, tally sheets etc.

So this thread will fall under 'Character'. I'll need your permission (along with Jeff's) to use information and submissions here to fill up that area. Will this be OK? I'd provide a Forestry forum link from the App...

Also it's probably a little too much to ask but would love some pictures to go along with your descriptions...

My computer eyes are exhausted and I'm signing out for the day  ::) lol.

Thanks again.