Oklahoma,AR,MO,KS,TX GTG (Next GTG 08/27/2016 ) Fort Scott, KS

[Freehand]

Looks kinda hedgey there Kenneth, nice planks. I see a wood planer in your future.

 

[RVALUE]

Wut vessel did you end up with Mr.Dan? Steve's right about the bar/temperature relationship……..would be interesting to experiment at 100 degrees, 150, 200, etc…….there's prolly a real sweet spot……..

No vessel yet.

However you are toying with 'drying too fast' with heat , which we know to be taboo.

You know it takes a month or so to properly dry wood, unless you are gambling.


Did you understand my idea about the vac, release. then vac release?

Once the internal pressure of the piece is the same as the external pressure, it may as well be in free air. Maybe

 

[RVALUE]

BTW, nearly got that reclaimed pine floor ready to install. Backed it up with 1/4 inch white backed mdf

Never before have so many experts been assembled in one place.


:hmm3grin2orange:

 

[WKEND LUMBERJAK]

Looks kinda hedgey there Kenneth, nice planks. I see a wood planer in your future.

They aren't as smooth as they could be but won't be slick when wet. full 2x8 +/-a smidge. definately stronger. very hard wood It used to be a corner post that was a little on the short side. ben in the post pile 5 or 6 years. I'm not a finish carpenter just a ROUGH IN GUY.

 

[Freehand]

They aren't as smooth as they could be but won't be slick when wet. full 2x8 +/-a smidge. definately stronger. very hard wood It used to be a corner post that was a little on the short side. ben in the post pile 5 or 6 years. I'm not a finish carpenter just a ROUGH IN GUY.

Once ya fool around with slabbing, a planer starts giving a lot of possibilities. A feller can't go wrong with an old Foley-Belsaw twelve inch with a Baldor under the hood. I've picked them up for $350, almost bulletproof machine.

I knew a feller a ways back in Newton county that had one rigged up with a Briggs and Straton gasser under the hood. Waaaaaay back in the woods planing away.

 

[Freehand]

No vessel yet.

However you are toying with 'drying too fast' with heat , which we know to be taboo.

You know it takes a month or so to properly dry wood, unless you are gambling.


Did you understand my idea about the vac, release. then vac release?

Once the internal pressure of the piece is the same as the external pressure, it may as well be in free air. Maybe

Oh yea, I get the pulsation angle. If you had them in a bound bunk, the heat, pressure, and steam would help stabilize the load. Like steam bending, except more like steam straightening. :misdoubt:

 

[RVALUE]

Oh yea, I get the pulsation angle. If you had them in a bound bunk, the heat, pressure, and steam would help stabilize the load. Like steam bending, except more like steam straightening. :misdoubt:

I believe what might be going on is: The pressure differential would 'pump' out the water as the air carried it trying to go to lower pressure. But once the internal pressure of the log is the same as the outside pressure, regardless of pressure, then the water movement would cease.

SO , one would put the vac, then allow to go to atmospheric. Then repeat. At a point, their would be no more moisture.

 

[RVALUE]

The device would be more complex, but you could do it with positive pressure. Bring the log up to say, 100 pounds, then release the pressure back to atmospheric.

It would act the same.

At the very end, bring the piece up to 180 degrees to kill the bugs

 

[RVALUE]

As per your steam straitening idea, one would need something that took up the slack automatically, and pulled to a straitedge. Would any spring we have do that? Or maybe an air bladder off a semi.

In actuality you would loose 10 pounds of pressure from the air bladders, as you applied vacuum.

just saying

 

[pdqdl]

On the vacuu-ln, I have an idea.

Rather than maintain vac for a duration, say 4 hours, it might work better 'pulsating' it in say 15 minute intervals.

This would 'pump' the water out. In the scenario where one maintained vac, once it reached equilibrium, it would cease to work any better than atmospheric.

Just a theory.

The equilibrium is not static: as heat comes into your system, the water continues to "gas-out", and your vacuum will continue to accelerate the drying process. If you just back off the vacuum and let atmospheric pressure come back into your vacuu-ln, there is a possibility that you will have as much condensation as water that you pump out. All you need is a check valve to prevent that.

If you have an airtight vessel, the vacuum will be maintained by a check valve until the water present in the wood has gassed out and re-filled the vacuum. When this occurs, the temperature is reduced by the same amount of energy needed to push the water molecules into the air from their previous state. A cheap electric heater would dramatically accelerate the drying process.

If you install a vacuum operated switch, it will only be necessary to have your pump come on when the pressure rises above a certain pressure. The vacuum pressure will be automatically maintained by the water present and the heat contained in your vacuu-ln. If the temperature drops down to icing conditions inside the cabinet, then your pump will stay off until adequate heat rise or evaporation. If you are pulling a high vacuum, then you can just sublimate the ice out without waiting for a temperature rise. A temperature gauge in the wood could actually serve as a moisture meter, if you are keeping it under continuous vacuum. When you reach room temperature under high vacuum...all the water is gone.

You should be aware that ALL the moisture you are removing will be going through your vacuum pump. Most refrigeration pumps can't handle that much moisture, and they burn up; much like a chainsaw running on straight gas. Vacuum pumps capable of handling the moisture from a wood drying process for a long lifetime are very expense. I have a simple water-pump and venturi concept that would be effective and cheap to maintain. Let me know if you are interested, I'll share.

 

[pdqdl]

The device would be more complex, but you could do it with positive pressure. Bring the log up to say, 100 pounds, then release the pressure back to atmospheric.

It would act the same.

At the very end, bring the piece up to 180 degrees to kill the bugs

What are you trying to do, kill bugs or dry wood? I guess I don't know what your project is. I thought you were working on a vacuum kiln.

 

[Freehand]

The idea is to ALWAYS kill the bugs. I told Dan about your wood drying method and some brainstorming went on……...

 

[pdqdl]

Vacuum and severe dehydration will get most bugs every time. Bacterial spores? Those guys are much tougher.

A pretty common player in the natural setting is a Tardigrade. These are the toughest critters on earth!

 

[pdqdl]

The idea is to ALWAYS kill the bugs. I told Dan about your wood drying method and some brainstorming went on……...

I have the whole thing built in my head. I just haven't ever done anything with it.

 

[atvguns]

Virginia Tech Solar Kiln | Dept. of Wood Science and Forest Products at Virginia Tech

 

[RVALUE]

It seems there is a wee bit of misinformation here.

As I see it, the vacuum is to accelerate the drying process without negatively affecting the quality of the wood.

ANY pressure differential will greatly affect the process. Where does the heat come in?

As I recall, and I'm not googling it, it is a 3 - 4 week process of increasing heat to kiln dry wood. Culminating with 180 or so degrees which is the bug kill.

My ancient memory, and I'm not googling it, is that we are 13 - 15 pounds of pressure now. So even taking the pressure down 2 pounds should really pump the water out.

My objective is to achieve this 2 pound (or whatever is easy) differential quickly, and when the internal pressure of the board equalizes, then allow to return to atmospheric.

It should 'fog' immediately with a pressure drop.

Two Assumptions:

Above Freezing
The moisture ladened air is removed from the environment via the vacuum

 

[RVALUE]

Maybe we are trying to take a 'wick' system into a 'pump' system.

I do not understand why we claim that air is 100 % humidity, and evaporation will still take place.

We know that moving air from pressure (fan) is more dense, and has greater pressure.

Moving air from creating a vacuum, is less dense and has less pressure.

Moving air from most people has no value.



Thanks for all your involved thoughts and comments.

 

[RVALUE]

Not to be argumentative, but I don't think we want severe dehydration, as the moisture will return and be just as detrimental as leaving it in originally and allowing air dry.


The reclaimed Doug Fir cabinet job I did in some instances took on moisture in the house and grew, much like redwood.

Now this apparatus would have application in 'kiln drying firewood' and I think it would kill enough bugs to be deemed safe.

Just saying.

 

[sawnami]

Some food for thought.>Robinair A/C Solutions

opcorn:

 

[john taliaferro]

One of the old piston compressors off something like my brown truck [78 ford ] will move the volume you need ,eat crap ,and cheep, they have oil separate in the bottom . 1/2 hp will pull it easy just check the oil often it will loose some past rings .