Boiling wood information

[Jim King]

We have finished the initial drying test using the boiling method. The charts need a little time to study and understand. One interesting note is that in the final drying stage the weight had practically no drop but the moisture content dropped considerably. This makes one think that the weighing method is not as accurate as one would hope. The other tests are standing still and look like they will probably take the one year per inch program to dry. The bagged pieces have not dried at all so if in a couple more months we have no advance I am going to abandon that test..

It looks as if when the bowls are final turned and finished the will be about 5% of the original weight of the fresh blank. The next and last report of boiling will be the finished weights and photos of each peice. I feel it is quite good to go from fresh from the jungle to about 5% in 5 weeks with no loss or cracking.

When studying the moisture chart you will see that all peices started out at 100% moisture saturation and quickly dropped. This is because our moisture meter only goes to 40% and gives a false reading on any thing above 40%MC and gives a false reading until they drop to 40% or less.

[Joe Tonich]

I don't know if I'm missing something, Jim, but it seems this method only works fast if you have a kiln. I'd like to see how long it takes without using a kiln for the last 2 weeks of drying. I'm not trying to be difficult, but most of us don't have a kiln to work with.

[Jim King]

I understand what you say, we used a kiln as it was the easiest way to finish them off. We have also after the blanks get to 13-14% MC here we have put them in the direct sun in the day time and in a couple of weeks they were down to 6-7%. This means that you dont need a kiln to finish and it will only be a couple of days more. The kiln is also a good torture test and none broke. If I did not have acess to a kiln I would direct sun dry the last couple of weeks flipping them a couple times a day.

The next interesting thing wil be if the finished bowls will end up at 5% of the weight of the fresh round blank. 95% of the blank made into scrap is quit a bit.

[Joe Melton]

Hello, Jim,
Here is something I copied from a website:

"Although some meters have scales that go up to 120%, the
range of moisture content that can be measured reliably is 4%
to about 30% for commercial dielectric meters and about 6%
to 30% for resistance meters. The precision of the individual
meter readings decreases near the limits of these ranges.
Readings greater than 30% must be considered only qualitative."
The site from whence this came is:
http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr113/ch12.pdf
Based on this, I think you should start plotting your data once the moisture meter reads less than 30%.
Best,
Joe

[Robert Mickley]

ok while all this testing is interesting, you haven't told me anything.
Comon sense and experiance from drying bowls tells me that if its going ot crack its going to do it long before it gets down to say 12 to 16 %. once a blank is that dry Short of subjecting it to high heat its not going to crack.



Joe
While boiling isn't as fast as say the DNA soaking it isn't as slow as just wrapping them in a paper bag. It will reduce loss to cracking to almost zero. I've found I can boil a 16 inch bowl that 1.5 inches thick set it aside and ignore it for about 8 to 10 weeks and finish turn it. While its not the 4.70 to 6.50 % of moisture that Jim is obtaining out of the kiln I've never had any trouble with one warping.
I've boiled in the neighborhood of 400 or so and some of those have left Ohio and gone to Arizona, on plane.

I would be willing to bet that if you went into any ones house with a moisture meter you wouldn't find a piece of furniture below 7 or 8 %

[Dennis Peacock]

I would be willing to bet that if you went into any ones house with a moisture meter you wouldn't find a piece of furniture below 7 or 8 %

Exactly!!!! I'd love to have a moisture meter and check my furniture during each season to see what it's MC is. I'm very sure it's drier in the winter and a lot more humid in spring/summer. I know this from watching the LOML's kitchen table I made here with breadboard ends. In winter? The bb ends are longer than the table is wide. In summer? The bb ends are shorter than the table is wide. Pretty wild to watch it. :D

[Jim King]

It is certailny true what was said of moisture meters when the moisture content is over 40 %. I would assume they are built that way on purpose as an economical measure as who needs to be told when wood is over 40 % moisture.

What I like about the boiling is the speed of drying, lack of cracking , stability and the ability to get a brilliant shine that will stay shinney. We used to have problems with our shine turning cloudy in a few months as the moisture in the peice tried to work its out way thru the wood. Now the shine lasts.

As for wood moisture content varience in this very humid climate it can vary from while in the sun drying in the daytime to when the sun goes down .

[Richard Madison]

Robert,
Please tell/show us what equipment you use to boil a 16" bowl (container, heat source, location, etc.).

[Jim King]

http://www.exoticwoodworld.com/index.php?c=static&sc=process