What does steam mean?

Digger Don · February 21, 2024, 04:24:12 PM

The other day, I was getting almost as much steam, as sawdust out of the discharge chute. It was a rather large red oak. Obviously (I think), it's from the moisture in the wood. I measured some of the boards and they were in the 15-20% range. Is the steam normal, or does it mean something that I ought to know? Dull blade? Poor setting of the teeth? Something else? Thanks. Don

GAB · February 21, 2024, 04:29:28 PM

DD:
How cold was it in your sawing environment?
Did you per chance check the temperature of your blade exiting the log?
GAB

Sixacresand · February 21, 2024, 04:36:46 PM

Usually when I see steam, the blade probably should have be changed several cuts before.

Digger Don · February 21, 2024, 04:38:46 PM

It was a cold morning, no doubt about that. Upper 20s, maybe? I did not check the blade temp, but guessed it had to be pretty warm. If it was turning moisture to steam, how could it not be? Am I missing something?

moodnacreek · February 21, 2024, 07:04:06 PM

I presume you are sawing with a mini band saw and there would be no board splitter so the saw can rub the wood. On a freezing morning and unfrozen logs all kind of things happen most of them not bad. If you could saw straight lines I would think things where fine.

Magicman · February 21, 2024, 07:26:10 PM

I see this if there is a quick turnaround of air temperature. If the air is much colder than the warmer moist sawdust, it's sorta like blowing your breath on a cold morning.

It's not unusual at all under the right temperature conditions.

Don P · February 21, 2024, 07:35:26 PM

Exactly, you were probably playing right around the dew point in that moment.

Digger Don · February 21, 2024, 08:02:04 PM

Moodnacreek - I'm not sure what you mean by a mini band saw. It's a Timberking B20. Is that a mini?

Magicman and Don P - I was hoping it was something like that. However, since I'm trying to sharpen my own blades, I figured it was a sign of something I did wrong. Thanks for the optimistic answers!
Don

SawyerTed · February 21, 2024, 08:06:43 PM

Last Wednesday was a cold morning here, in the upper 20s. The logs were dead white oaks and had laid in the weather for a few weeks. The logs had plenty of moisture in them. Had steam with a new blade until the air temperature got up near 40 ish.

Southside · February 21, 2024, 10:56:32 PM

Quote from: Digger Don on February 21, 2024, 08:02:04 PMMoodnacreek - I'm not sure what you mean by a mini band saw. It's a Timberking B20. Is that a mini?

To Moodnacreek any bandsaw that runs a band under 12" wide is a mini...

YellowHammer · February 22, 2024, 12:38:14 AM

Steam can be no problem, but is also an indicator of a possible band, alignment or sawing problem, most times either accompanied by excessive sawdust spillage in the kerf, or cutting slight waves, any reason for the body of the band causing friction and localized heating. Look for packed sawdust, waves in the kerf, anything that would cause friction, or causes a higher load than normal on the engine due to sharpness or other absorbed horsepower reasons. That HP is going to go somewhere, and usually manifests itself as steam.

I did a video on this very subject where I could take two different new bands, one "good" the other "not good" and the immediate indicator of reduced cut quality and performance was steam out of the cut, which I managed to catch on camera.

Unusual and noticeable steam is an indicator, certainly only maybe of dew point, but maybe of more, and certainly warrants closer inspection.

Digger Don · February 22, 2024, 06:32:47 AM

As a rule, there is quite a bit of sawdust left on the boards. From what I've read here, that might be a set problem. The mill's owner doesn't agree. Besides, neither one of us have figured out how to use the setter.

customsawyer · February 22, 2024, 06:39:13 AM

Lots of things can contribute to sawdust on the boards. Sawing to slow is one of them.

ladylake · February 22, 2024, 07:19:36 AM

Quote from: Digger Don on February 22, 2024, 06:32:47 AMAs a rule, there is quite a bit of sawdust left on the boards. From what I've read here, that might be a set problem. The mill's owner doesn't agree. Besides, neither one of us have figured out how to use the setter.

More set more sawdust

less set less sawdust Steve

YellowHammer · February 22, 2024, 07:39:30 AM

Yes, all things being equal and good, there should be very little sawdust on the boards, a scattering or light layer, at best. Packed four like is very bad, and drives the band, and so is pitch buildup, bite of which really heat up the band.

Sawing slow is a main contributor, but most times people saw slow is because if they speed up they get waves, although some just prefer to ease along. However sawing fast and clean lets the moisture in the wood help cool the band, so the faster you saw the cooler the band stays. Set is also a contributor of sawdust, and sometimes more set helps, sometimes more set spills sawdust and keeps if from being ejected, but you'll generally be able to gauge proper set by speed. Faster and straighter sawing is best. Sometimes even new bands are not good out of the box, use a set checker tool to confirm the band is up to snuff. The video below discusses these things, and it should be noted that it was shot with 2 brand new bands, both straight out of the box. Steam at 7:38 in the video.

https://youtu.be/RpzucyxlTYc

Magicman · February 22, 2024, 08:07:57 AM

Quote from: Digger Don on February 21, 2024, 04:38:46 PMIt was a cold morning, no doubt about that.

In this instance, I doubt that the phenomenon that Don described had anything to do with the blade. It was simply a cloud of condensation that occurred when the warmer moist sawdust hit the cold air. I have seen it happen many times on a cold morning and as the temperature warms up, it quits.

I very well remember this cold November morning with the temperature in the 20°'s. It was already foggy and when I started sawing I had my very own fog making machine.

Chuck White · February 22, 2024, 08:14:01 AM

I used to see steam exiting the sawdust chute, mostly in the Spring and Fall seasons.

Whenever I saw steam, there were usually ice crystals on the lumber, so I do believe that the steam is caused by the warm blade cutting through the frosty cant!

It's normal if you're sawing in cooler temperatures!

Digger Don · February 22, 2024, 08:47:59 AM

My ignorance is about to show itself, again. I suspect I might be sawing too slow, but if I go much faster, the engine stalls. Under no load the engine runs about 3,600 RPM. I try not to let it go much below 3,300, which means going slower. Me thinks me poor sharpening skills are showing through.

But, if that's the case MM might be mistaken. What a conundrum.

YH, if you'd consider moving to New Market, VA, I could pester the heck out of you!

moodnacreek · February 22, 2024, 12:41:19 PM

Quote from: Southside on February 21, 2024, 10:56:32 PM
Quote from: Digger Don on February 21, 2024, 08:02:04 PMMoodnacreek - I'm not sure what you mean by a mini band saw. It's a Timberking B20. Is that a mini?
To Moodnacreek any bandsaw that runs a band under 12" wide is a mini...

Make that 2". In New York the D.E.C. lists bandsaw, circle and mini bandsaw. Southside, how's that robotic milker going?

Digger Don · February 22, 2024, 03:37:59 PM

I guess it is a mini, then.

At first, I didn't appreciate your comment. Then, I realized my 8,000 LB. excavator is considered a mini. I wasn't aware of how big a band mill could be. So, no offense taken. Thanks to all for your comments. Don