Friday, May 24, 2013

Ahh... The Perfect Summer Day On Repeat

So, I have finally got my first batch of beech plane blanks out of the kiln. I have dried steambent wood parts in my small light bulb kiln for chairmaking for quite some time now. That is a whole different process really than when drying wood blanks to make wooden plane bodies.

What is my aim when drying wood for plane blanks? Well, with a background in working greenwood I always have appreciated how wood works that has been air dried. It is just different. I don't want to over rate it but the way the tools cut it is just different. As you can imagine I prefer it to the super dried stuff.

The difference lies in the fact that air dried wood never gets to a high temp like typical kiln dried wood. In the kiln the temp will generally get to the 160˚ range for many woods and some are higher. This is often done just to be safe and kill bugs or to set pitch in resinous woods like pine and to get the wood dried to a very low moisture content. However, it isn't actually necessary to heat wood this hot to dry it.

It is important to appreciate that commercial kiln operators are concerned with speed since this affects profits. Not knocking this, they are businesses, after all. However, the resulting product is not as good as it could be for the artisan woodworker. I have been completely sickened at times to have bought a wood like white oak that was beautiful wide boards and paid premium prices to only find that 30-40% was a waste because of drying defects hidden within the wood.

Anyway, these sorts of things, among the fact that I couldn't find certain wood cut and dried in the orientation or sizes that I wanted, lead me into the kiln drying business. ...for myself of course.

So I started researching this about a year ago and decided to go with a low temp dehumidification kiln. It basically allows me to control the environment in a closed chamber. Imagine wood drying on a perfect summer day at the optimal range of temperature and humidity for that wood. Now recreate that day over and over until that wood is dry. That is what this kind of kiln allows me to do. The blanks I am drying never get over 105˚ or below an average moisture content (MC) of 10 percent.

Yes this can take longer than a high temp (HT) commercial kiln but not very much longer. For most hardwoods it can be dried just as fast. In fact since I am not super drying the wood to, say, 6-8% MC (because these will be used in a open shop environment) then I don't have to dry as long. An advantage is that a low temp dehumidification kiln uses way less power than conventional kilns. Mine can run 100% of the time for 30 days for around $53. Of course, high tech kilns like this are not cheap to begin with. Think hybrid electric cars, you pay up front to get low operating cost.

I think this is the best of both worlds. After all there are drawbacks to air drying lumber. Air drying can take several years, first off. It is also subject to a lot of drying defects in actuality since you can't control the weather, as we all know. Surface checks are very common in air dried wood and then there are woods that are very susceptible to stain from mold and fungus if not dried quickly enough or cut in the "wrong" season. Beech is one of the worst for both surface checks and fungus stain when air dried.

Here are a few pictures from the process. I wish I had some of the log getting cut up a Curtis' place. Thanks again Curtis for letting me use your yard!

Haul it...

...cut it...

...stack it...

...load it...

...check it...

...start making it...

...finish making it...

...use it... (nice hair!)

...stack it... Wait, didn't I already say that?


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  2. Hello James. Your work is excellent, congratulations. I agree with your philosophy of sustainable and healthy work, and solid wood of course. Have you had any experience with solar dryers? Greetings.

    1. Martin,

      I have not had any experience with solar driers but I have researched them. It is like many things, there are drawbacks but if you are willing to work with that it is a very reasonable option to dry wood. Your particular location will have a great affect on when to cut your wood and how long it will take to dry.

      The forestry department and USDA have some good resources that discuss in great depth about drying wood and kiln operation. It is all free just do some searching online. It is quite dry reading but very useful none the less.


  3. Can you share how much waste you had right out of kiln? As you pointed out there are any number of defects you can encounter when drying wood. I just spent several weeks sourcing quartersawn beech here in the Midwest so this post was of great interest to me. I am just starting my first set of hollows and rounds so your site has been a great read. Thank you for sharing your plans and experience. Keep up the great work.

    Brian Z

    1. Brian,

      I actually had virtually no waste but this is not my first time drying wood but this is a new kiln setup for me. I did have a fair bit get some spalting (fungus) before I could get it cut an into the kiln. That is the biggest problem with beech right off the bat. The other is that it will check on the tangental (plainswan) face of the board very easily. You have to dry it in a very controlled way. The initial moisture content loss down to 30% is critical that it is at a very slow rate.

      I should put up a post about it that might help to explain why beech is so hard to dry without defects.

      All that said I did have quite a bit of problems with the large bench plane bodies. I was not able to put them in the kiln at the same time as the smaller stuff so some suffered either spalt or checking.

  4. Great information! What are the demensions of your "large" bench plane bodies? What is the capacity of your kiln? It looks fairly large from the photos. I am starting to appreciate the kiln dried beech I found even more after seeing your process. Thanks again for the post.

    1. Brian,

      I have been cutting them at a variety of sizes. I haven't settled on a particular dimension just yet for the bench planes. I have dedicated my time up till now making side escapement planes so I am really just beginning on the bench plane sizing that I want to settle on. I don't want to send you in the wrong direction by throwing a dimension out there.

      The capacity of my kiln is 1000 board feet but I probably have only had about 300-400 at the most in it so far. I will be doing some eastern white in a while that will be to capacity. You can't mess that stuff up. Will dry in about two weeks or so @ 4/4.

  5. Caleb,
    Great site,I just discovered your site a couple hours ago.
    I have the side escapement moulding plane fever!
    My goal is to try and make a 9 pair half set of hollows and rounds. I don't know if I'll be able to make side rounds and snipes- bill or not? Maybe after my confidence grows.
    I need 1/4 sawn beech and it looks like you might save my day. Please put me on your list.
    Will you be selling side rounds and snipes-bill planes?
    best regards,
    Doug Moulder

  6. Doug,

    Yes, I understand your fever. I am crazy sick as well. :)

    I intend to make these for sale in a variety of styles including the side round and snipe bill. I have been so busy with my chairmaking and design work that I haven't had the time to get to make more of these as of late.

    In about a year I should have more time. Gosh... did I really just say that?