Just found this forum, my head hurts from info overload

Hoopty5.0 · August 09, 2019, 09:40:04 AM

Oh, man. I stumbled in here after finding the milling forum and now my head hurts from absorbing so much info... or trying to at least. I had no idea there was so much precision involved. I plan to continue to educate myself by reading, reading, reading.

In the mean time, I have a shed that I've half way converted into a solar kiln, in complete blissful ignorance. I've sealed up the cracks, it's got two vents on the bottom of two sides, and the double doors leak enough to be called vents as well. I've got 5 slabs of 6/4 walnut and an assortment of pecan as well, as pictured:

My question is - If there was one glaring issue I needed to fix to be quasi-successful in drying this wood, what would it be? The pecan is common and I won't lose any sleep over ruining it, but being in SE TX, the walnut is worth its weight in gold, and I don't want to ruin it.

The walnut logs were harvested in April from a construction site, and have been laying out until it was milled a week ago. From there it went into the "kiln" where measured temps are 120° during the day and the de-humidifier says 30% moisture in the air.

Thank you kindly for any information you're willing to share.

Texas Ranger · August 09, 2019, 11:50:11 AM

air circulation through the pile

alan gage · August 09, 2019, 12:46:30 PM

Quote from: Hoopty5.0 on August 09, 2019, 09:40:04 AMin complete blissful ignorance

Isn't that the truth. My sawing life would be a lot easier if all these guys would stop showing me the right way to do things.

Welcome to the forum. It's a great place.

Alan

Brad_bb · August 11, 2019, 11:18:15 PM

Did you seal the endgrain?

Hoopty5.0 · August 12, 2019, 08:42:02 AM

Quote from: Brad_bb on August 11, 2019, 11:18:15 PM
Did you seal the endgrain?

No, I didn't. Is it too late to do that? Do I need to cut a couple inches off first then seal?

mredden · August 12, 2019, 04:23:43 PM

add a cheap box fan.

doc henderson · August 12, 2019, 06:27:25 PM

did it air dry first?, do you have a moisture meter and can you check the wood. I assume it is well over 32%. is the solar part just windows? how many square feet. what is the peak day and night time temp in the kiln. @GeneWengert-WoodDoc . walnut is pretty easy. if you have end check it is prob. from the log just setting.

YellowHammer · August 12, 2019, 10:49:35 PM

Congratulations, and nice to meet you.

You got some real nice wood there, and if you were asking how I'd stack them to reduce risk,

I'd move the stickers way out to the end, as long as they are still in top of each other. They act as moisture reservoir and will very effectively arrest end cracking due to over drying from the ends of the slabs. They will hold just enough moisture to make a difference.

Certainly, end sealing is a good idea, unless cracks have already formed or a few days have passed. It really only works well on a fresh ends, and if I was to apply it to existing stacks, I'd chainsaw packsaw all the edges at once and apply it on.

You can't really do anything about stress cracks, unless you hammer in some inserts.

I'd recommend putting weight on the stacks, any that you can. I'm not a big fan of flexible strapping or ratchet straps to help flatten, because it doesn't put enough load on the pressure points due to its flexibility. It helps with bow but does little for cup. I have, however, had success with strapping by putting a stiff, inflexible cross piece under the straps on the top of the stack. Something stiff, like a 6x6 or similar.

Something I always like to do is put my thickest and most valuable pieces lower in the stack, with the cheapest and less valuable on the top. They act as weight for the lower layers.

I can't tell from the photo, but I will always stack slabs with alternating rows of grain orientation. Basically cup up for one row, cup down the next, cup up the next. Smile up, smile down. This keeps contact loads high when the wood tries to cup and helps keep it flat. Basically like this except vertically: )()()(
If the wood is stacked randomly or worse yet, all with the grain in the same potential cup direction, it will develop "sympathetic cup" where boards that may not have a tendency to cup will be forced that way by adjoining faces to look like this: (((((((

Good job.

Hoopty5.0 · August 13, 2019, 09:12:41 AM

Quote from: YellowHammer on August 12, 2019, 10:49:35 PM
Congratulations, and nice to meet you.

You got some real nice wood there, and if you were asking how I'd stack them to reduce risk,

I'd move the stickers way out to the end, as long as they are still in top of each other. They act as moisture reservoir and will very effectively arrest end cracking due to over drying from the ends of the slabs. They will hold just enough moisture to make a difference.

Certainly, end sealing is a good idea, unless cracks have already formed or a few days have passed. It really only works well on a fresh ends, and if I was to apply it to existing stacks, I'd chainsaw packsaw all the edges at once and apply it on.

You can't really do anything about stress cracks, unless you hammer in some inserts.

I'd recommend putting weight on the stacks, any that you can. I'm not a big fan of flexible strapping or ratchet straps to help flatten, because it doesn't put enough load on the pressure points due to its flexibility. It helps with bow but does little for cup. I have, however, had success with strapping by putting a stiff, inflexible cross piece under the straps on the top of the stack. Something stiff, like a 6x6 or similar.

Something I always like to do is put my thickest and most valuable pieces lower in the stack, with the cheapest and less valuable on the top. They act as weight for the lower layers.

I can't tell from the photo, but I will always stack slabs with alternating rows of grain orientation. Basically cup up for one row, cup down the next, cup up the next. Smile up, smile down. This keeps contact loads high when the wood tries to cup and helps keep it flat. Basically like this except vertically: )()()(
If the wood is stacked randomly or worse yet, all with the grain in the same potential cup direction, it will develop "sympathetic cup" where boards that may not have a tendency to cup will be forced that way by adjoining faces to look like this: (((((((

Good job.

Thank you for the reply, great information! I have some treated 4x6 that I've had for many years (it's dry) that I can cut up and use at the top of the stack. But all good information, most of which I overlooked initially. The walnut is my most valuable, but I need to check the grain orientation. The pecan has been a learning curve for sure, luckily I have very little money in it and is not great loss.

Quote from: doc henderson on August 12, 2019, 06:27:25 PM
did it air dry first?, do you have a moisture meter and can you check the wood. I assume it is well over 32%. is the solar part just windows? how many square feet. what is the peak day and night time temp in the kiln. @GeneWengert-WoodDoc . walnut is pretty easy. if you have end check it is prob. from the log just setting.

The walnut logs were cut down in early april and have been laying out since about 2-3 weeks ago when they were sawn. The MC of the walnut is in the high teens/low 20s, the pecan was 10-12% last I checked.

Shed is 8x12 (think prefab shed from Home Depot) with shingle roof and 2 small windows. It was 125° in there yesterday afternoon, seems to get down to ambient (80°ish) at night. I have a dehumidifier running constantly, roughly 30% humidity.

I have a lot of logs left to saw and want to get the process right before go any further. Sounds like air drying before going in the shed is important. What MC should it be before it goes in the shed? Also, I read about over drying somewhere. Why is that bad?

Thank you again for (both of) your input.

GeneWengert-WoodDoc · August 14, 2019, 09:38:06 AM

End coating or logs or lumber must be done before any drying begins in order for the coating to be most effective. The coating prevents new checks from forming but does not control existing checks.

doc henderson · August 14, 2019, 09:45:12 AM

some wood such oak need to dry without too much moisture gradient and slower, so let the humidity get higher in the beginning. most defects happen early even if you do not see them till later. for others such as walnut, you can air dry so you are not paying for electricity to do what outside air can do down to say 12 %, then start paying electric to take it down to say 8%; if you over-dry you are wasting time and resources, it will not machine as well (think brittle and chipping out in a planer and shaper) and if you build something at 5% and it regains moisture back up to 8% it will swell and potentially destroy complex joinery. there was a pdf on drying in the sawing project 2019 thread by Dr. Wengert. it gives lots of basics and the book on line on drying hardwood lumber. @GeneWengert-WoodDoc end coating and out of direct sunlight are important especially for walnut. good airflow on softwoods and stain prone wood such as maple. lots to learn. best wishes!

doc henderson · August 14, 2019, 09:55:43 AM

DH DRYING HANDOUT.pdf (2533.8 kB - downloaded 93 times.)

Perlandra · August 19, 2019, 09:17:02 PM

Quote from: alan gage on August 09, 2019, 12:46:30 PM
Quote from: Hoopty5.0 on August 09, 2019, 09:40:04 AMin complete blissful ignorance

Isn't that the truth. My sawing life would be a lot easier if all these guys would stop showing me the right way to do things.

Welcome to the forum. It's a great place.

Alan

I am more than ignorant, but I'm going to plug away! My brother was recently out and our neighbor had a dead Ponderosa Pine tree that needed cutting. I had him cut me a slab as I wanted to make a small table. It has the bluish areas in the pine slab that is often seen here once the beetles got it. I purchased Polyethylene Glycol as I had read that this is used in trying to keep it from cracking. I found a plastic container that would fit the piece. Today I received the PEG. I read where it sounds as if I should soak it for at least 25 days (softer wood than maple) at 70º. I'm a bit out of my league here and am unsure of where to actually keep this wood soaking. The only option I have is to put the container in a room in the house and close the door to keep it at an even temperature. Suggestions? I want to do this all myself, even down to the belt sanding, but I will have my son make the legs. I plan on covering the container with plastic (can't use cover as I will need to put a rock on top of the wood piece.) It is 20 inches in diameter and about 3 inches thick.
Nanc

doc henderson · August 19, 2019, 09:49:23 PM

that seems like a long time for peg. it varies by peg concentration and temp. should be some articles. we call those cookies if it is a crosscut round section of a log. can also soak in denatured alcohol and it is cheaper. it may still crack some but less if peg soaked and slow dried. the blue is usually blue stain in pine. spalting follows grain and is most in sapwood of hardwood species. hope it turns out well and send pics when you can.

GeneWengert-WoodDoc · August 20, 2019, 08:14:24 AM

As you soak wood in PEG solution, the PEG moves into the wood and water moves out, weakening the solution. If you keep adding more PEG so the solution stays at full strength, you can shorten the time. Hotter is shorter. Smaller pieces take less time.

Perlandra · August 20, 2019, 09:18:05 AM

Thanks for the info on PEG soaking. I will see what I can do. I'm thinking I can't put it in a room in the house because of the chemical smell. I guess I should open the container and see how bad it is. May just have to sit in the garage somewhere. I have to figure out where to post pictures of the slab BEFORE soaking. There are some cracks already, but I don't think they are bad.

Nanc

doc henderson · August 20, 2019, 11:40:03 AM

welcome by the way. cookies can be hard to dry, and the larger the diameter the more likely to crack. there are threads on cookies and drying and tutorials on posting. It also is a learning curve. i tend to take pics with my phone and have the forum upload page on my phone so i upload from my phone to the forum. when I make a pic. post I do it on my computer. you make a reply. type text and then it is good to down space a couple clicks then click the add photo to post bar, choose my gallery, choose a photo, rotate it to get the proper orientation if needed, then click submit and then ok. it will add to your post. you may continue to add text and photos, make corrections ect. then hit post. if you look after posting, and find a mistake, you can then hit modify and go back to the worksheet to correct, then re-submit.

it will put the pic where you left the cursor which is why a few spaces is good. you can backspace and remove a pic just like text. you may have to x out of or minimize the gallery pic to see your post again.
you have to put pics into the gallery and add them to posts from there. you can use them more than once as the pic is a link to the gallery. you cannot add them direct to the post. video requires a you tube account i believe. you should not add a bunch of photos that you do not intend to use as it takes up space.

doc henderson · August 20, 2019, 11:46:19 AM

i have not noticed smell to the peg. it can get a mold or the wood may put off a smell. ethylene glycol is the active ingredient in anti freeze. the many small molecules lower freeze point and raises the boiling point of liquids like water. just like salt NaCl. PEG is a chain of these molecules hooked together so it is not toxic, and acts like a wax to displace water and stabilize the wood for drying by reducing the shrinkage. i have use it a few time and had good luck but it is expensive. search cookies.