Banjo Hangout Logo
Banjo Hangout Logo

Premier Sponsors

572
Banjo Lovers Online


Oct 4, 2021 - 10:55:03 AM
58489 posts since 12/14/2005

On Sept 10th, I enclosed the walnut I'm drying, and I've measured the water from the dehumidifier.
Don't know how much of the water was pulled from the ROOM air which may have leaked in through the plastic, but the total is over a gallon, and the hygometer reads 43%, while the house is 63%


Oct 4, 2021 - 12:24:20 PM
likes this

mbanza

USA

2404 posts since 9/16/2007

Commercially kiln dried wood comes out at 6 to 8 percent. 43% is way too high. The air inside the kiln will read differently than the wood itself.

Oct 4, 2021 - 12:44:11 PM

Owen

Canada

9823 posts since 6/5/2011

I've never had/used a moisture tester... about all I know is that Amazon has 'em..... some don't look particularly pricey, and maybe if you have one you'll find enough things to test you'll wonder how you ever did without. wink

Edited by - Owen on 10/04/2021 12:44:40

Oct 4, 2021 - 2:26:47 PM

blm10jn

USA

611 posts since 10/28/2010

You really need a good moisture meter to dry wood with a dehumidifier in an enclosed area. The RH of the enclosed area, room ,box etc does not indicate the dryness of your wood.

Oct 4, 2021 - 2:27:49 PM
likes this

blm10jn

USA

611 posts since 10/28/2010

Also good moisture meters cost. Don't waste $$ on a cheap one.

Oct 4, 2021 - 3:48:32 PM

YellowSkyBlueSun

Virgin Islands (U.S.)

467 posts since 5/11/2021

In my experience, your typical residential freestanding de-humidifier struggles to bring RH down below 40%. My basement mechanical room is typically 60% RH without a dehumidifier (~12x20 room), and with a dehumidifier running 24/7/365 it doesn't go below 45%. YMMV.

Oct 4, 2021 - 4:41:13 PM

2631 posts since 5/2/2012

Awhile ago I was watching a wood turning show on PBS, and the host did a segment about a wood kiln DIY project using an old fridge and light bulb(s). Don't remember if there was a fan involved. As I recall the person who built the kiln turned bowls using green wood, then used the kiln to dry them out. Would probably work for stick lumber as well. Google DYI wood kiln and you might find something you like.

Oct 5, 2021 - 8:48:42 AM
likes this

lapsteel

Canada

636 posts since 8/13/2015

It’ll air dry well. Just weigh the same piece weekly and write the weight down. When it no longer changes much from week to week, it’s dry. Fall and winter is a good time to do this.

Oct 5, 2021 - 9:30:36 AM
like this
Players Union Member

RioStat

USA

5638 posts since 10/12/2009

A couple hours in the sun oughta do it..........OHH! I'm sorry, I thought you said "drying your kilt" !


 

Edited by - RioStat on 10/05/2021 09:31:12

Oct 5, 2021 - 6:04:17 PM

bubbalouie

Canada

15505 posts since 9/27/2007

I can't tell if you have thin pieces of wood separating that nice looking lumber . We called them stickers. They let the air flow between them. You can put wax, paint or oil on the ends to prevent checking.

Oct 6, 2021 - 4:12:42 AM

2350 posts since 2/7/2008

If you have a scale that can measure grams, weigh a board once a week for a few weeks and note the weight each time. If the weight stays the same, the moisture content of the wood has reached equilibrium with the surrounding air and that's what you want. If the wood keeps losing weight, you're not there yet.

Oct 6, 2021 - 5:42:46 AM

58489 posts since 12/14/2005

I've got stickers.
I've got a fan.
And if I take a piece OUT to weigh it, I will be allowing damp house air to enter the kiln chamber.
I guess I'll cut a flap, remove a piece, saw a block off the end, weigh it, record the weight, replace it, and duct tape the flap shut.

Am considering putting in a hair dryer, and unplugging the fan, with the hypothesis that warm air is going to dry it quicker.

Oct 6, 2021 - 8:03:33 AM

78 posts since 12/12/2019

You can get a moisture meter at lowes that takes a 9v battery, those cheap ones on amazon require a special battery once the original goes dead. To measure the moisture content you have to split a piece of wood and measure the fresh split along the grain all other measurements will be way off. This is the only way to see what is going on inside the wood.

Oct 6, 2021 - 8:28:45 AM

YellowSkyBlueSun

Virgin Islands (U.S.)

467 posts since 5/11/2021

mike gregory Could you put the entire stack on a scale, so you could track the weight change without opening the chamber?

Oct 6, 2021 - 9:21:54 AM

58489 posts since 12/14/2005

Oh, HdevilLL no!

Actual 2 by actual 4 inches, no less than 30 inches long, times a dozen, plus the weight of the dehumiliator. That's got to be several hundred pounds.

Simpler to trust my kitchen scale, a 4x4 block, and duct tape.

And, once I take them ALL out to start using them, they will start to absorb moisture from the air in my  Secret Underground Lab, anyway.

Oct 6, 2021 - 10:55:44 AM
likes this

1647 posts since 7/2/2007

I'd keep the hair dryer out of the mix, they are not meant for continuous duty and you might dry the wood faster or maybe burn down your house. Experimentation is fine, just keep it safe.

Math can be your friend!

Average dry weight of walnut is 38 lbs per cubic foot.

A 2x4x30 neck blank is about 1/7th of a cu ft.3

38lbs divided by 7 = about 5.5 pounds

So, pull out a piece 2x4x30 and weigh it.

If it around 5.5 lbs you should be pretty close to dry.

Sure, it's not perfect but if you want better you'll probably have to pay for it in a good moisture meter.

Or take a piece out of your dryer, let it acclimate in your shop for a couple weeks and call around to cabinet shops or lumber yards and find someone with a meter they could check your wood with.

Oct 6, 2021 - 5:21:48 PM

58489 posts since 12/14/2005

Based on advice from several OutHangers, here's what I id.
Cut 3 chunks, about the size of two sticks of butter, side by side.
Weighed them on the kitchen foo scale, made a mark where the needle pointed.
Put one back in the kiln, will check it Nov first or so.
Put the second in the Air Fryer, set it on DEHYDRATE
(That will be 140 degF for 8 hours.)
Put the third one in the microwave on HIGH for 3 minutes, will let it cool and repeat, several times while the dehydrate cycle processes.

Whichever of those two gets lightest, after a few days, will be The Standard by which Block #1 gets measured.

Sound anywhere near SANE?

 

Or should I do like this gal did, and quit while I'm a head??

Oct 6, 2021 - 6:31:53 PM

58489 posts since 12/14/2005

Oooh!
Looks like 3 min in the microwave may have sounded like a GOOD idea at the time, but when I took it out, after it had cooled, and weighed it, it weighed the same.
So I put it back in, set it for another 3, went downstairs to load the washer, ame back to a kitchen full of smoke.

The danged thing was burning... from the inside!

GOOD news is: My smoke alarm did NOT go off, so I know FOR SURE that it's not working like it should, and will replace it forthwith.


Edited by - mike gregory on 10/06/2021 18:40:30

Oct 6, 2021 - 9:53:53 PM

rmcdow

USA

1035 posts since 11/8/2014

Kiln drying is not what it sounds like, as it is not only pulling moisture from the wood. To undertake kiln drying in a way that you end up with wood that is stable, the best thing is to air dry the wood to about 20% moisture content, then kiln dry it to 6 - 8% in a kiln that controls both the temperature and humidity. The humidity is kept high during this process, typically above 85%, so that the moisture is drawn out slowly from the wood to keep it from case hardening. It takes about 10 days in a well regulated kiln to bring the wood moisture content from 20% down to about 10% without case hardening occurring, If you use a vacuum kiln, this time can potentially be reduced, depending on the wood species.

In wood, there is free moisture and bound moisture. Free moisture comes out during air drying, and if this is done over a year per inch thickness of wood, there is not a lot of chance of case hardening. If it is done in a vacuum kiln, it can be done quicker without case hardening. After the free moisture is out for the most part, the wood is going to be around 20% moisture or so. The bound moisture will continue to come out slowly with air drying, but it is fairly safe to then use kiln drying to reduce the moisture content faster, getting it down to the 6 - 10% level.

I have dried wood using a freeze dryer, where the moisture is pulled out of the wood with a vacuum and condensed on the inside of the freeze dryer (at -35 degrees C). This appears to eliminate case hardening, but it doesn't allow the wood fibers to settle in the position they would during normal drying. I freeze dried banjo rims that were at 60% moisture down to 8% moisture without any dimensional change. I turned them to 11", and two years later they were at 10.625", still at 8% moisture.

This has all demonstrated to me the importance of not rushing the drying process, and also understanding what is happening in the drying process so that I can anticipate issues before they show up. I've glued an 8% moisture fretboard of ebony to an 8% moisture piece of carob, shaped it into a neck, and it bowed back over the next two years as the carob shrunk during the settling process of the fibers.

Hoadley wrote a book called Understanding Wood that is very informative along these lines. I've seen a pdf copy on the internet, it is the same book I have in print, but not all that sure about copyright infringement.

Edited by - rmcdow on 10/06/2021 21:54:23

Oct 6, 2021 - 10:26:02 PM

58489 posts since 12/14/2005

I shall have to ask around and see who can do this for me, at what price, since I don't want to wait fifteen months before I can start using this wood.

On the other hand, I've got projects I still haven't finished, after being started, from three or four years back, so, maybe I should just let the walnut sit until THOSE are done.
That might easily take a couple of years.

Oct 7, 2021 - 4:07:37 AM

58489 posts since 12/14/2005

Block which was in the dehydrator seems to weigh exacatrackally the same as when it went in.Maybe I should take it to the drugstore, have THEM weigh it on their super sensitive scale.

Or, maybe I should stop caring.

Oct 7, 2021 - 4:27:33 AM
likes this

1394 posts since 9/6/2019

quote:
Originally posted by mike gregory

Block which was in the dehydrator seems to weigh exacatrackally the same as when it went in.Maybe I should take it to the drugstore, have THEM weigh it on their super sensitive scale.

Or, maybe I should stop caring.


Mike, you may be able to find a sawmill that will slide your boards in their kiln when they are drying their own lumber. I know a couple of the ones around here will do that for you if they have a short load and, IIRC, they don't charge a lot to do it.

Oct 7, 2021 - 3:19:43 PM

rmcdow

USA

1035 posts since 11/8/2014

quote:
Originally posted by mike gregory

I shall have to ask around and see who can do this for me, at what price, since I don't want to wait fifteen months before I can start using this wood.

On the other hand, I've got projects I still haven't finished, after being started, from three or four years back, so, maybe I should just let the walnut sit until THOSE are done.
That might easily take a couple of years.


Chuck Ogsbury lets wood sit in his shop in Boulder for 10 years before he will use it for a banjo.  There is a lot of wisdom in that, and I have taken that approach myself to some extent.  It means stockpiling a bit of wood for future projects, and also monitoring it every couple of years for changes in weight and dimensions.  Once I got started in this way, I don't really have a shortage of wood, as it seems to me, living where I live in the middle of essentially a hardwood rain forest, that I collect a lot more wood than I will ever use.  

Hangout Network Help

View All Topics  |  View Categories

0.2649994