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To answer some of the other questions asked, 

The 10% rule, no, this isn't a hard rule or stop.  Many places in the country will never see 10% mc no longer how long you wait. 

There is a theory called equilibrium moisture content or EMC, very simply put, this is the place where the the moisture content within the wood is equal to the environment  around it. The wood will shed and take on moisture as the ambient humidity changes. As I understand it,  EMC should be the goal of wood to be ideally ready to work. Not an arbitrary #.

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Unless you live in the jungle, you should be shooting for 10% or less.  Ideally 6%.  Out in the desert where you are, less.  This is what kiln drying does for you...pushes out all the moisture from the board through and through, then AFTER it has been thoroughly dried, can successfully reach EMC in any environment it's allowed to acclimate to.  Yes if you leave boards air drying for long enough in the Mojave Desert they will eventually be bone dry.  This doesn't mean that Grandpa's elm tree that's been in the barn for two years is ready to work.  Kiln drying creates conditions with wood that are predictable and consistent.  The major fluctuations in MC are over at that point, and the greatest changes that wood will ever experience are those in sync with its surrounding environment.  Enter Shannon's dry creek bed and flash flood analogy.

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To answer the unknowns, this wood is ash cut about mid-late July sitting in 100*(nuclear fallout) of California. Mc is mid teens depending on what board. Tree was dead standing 2 years before coming down. 

If kiln drying was an option, I'd happily pay someone to do it,  I have exhausted every Avenue I know if and cannot Find a single one in southern California. 

There’s nothing wrong with working with less than fully-dried lumber if you account for future wood movement in the design. Just ask Peter Follansbee.

This is what I would do. If your ash lumber is cut in such a way that you can orient the boards for your bench top so that the growth rings wind up running vertically, then go for it. As the boards continue to dry out, they will mainly shrink top to bottom, meaning that you’re going to mitigate any wood movement issues as that process goes forward. In fact, by doing so, you’re essentially making a big laminated quarter sawn slab for your bench top. This is what I did for my bench top, and it’s awesome.

If your boards won’t allow you to do that, and you still want to make a Roubo, orient the boards for your bench top so that the heart side of the board is facing upwards. In that orientation, the bench top will tend to move so that it cups on the bottom side (See the top block in the diagram. This is your bench top upside down.). If the bench top moves this way as it dries, the tops of the legs will move inward, causing a splay in the legs, making your bench more stable.

In fact, that’s what Roubo says to do with the big slab of wood used to make Roubo benches back in the day. And I’m relatively sure that they didn’t wait until the 20” wide, 6” thick slab was down to less than 10% MC before putting it to use.

 

wood-handbook-fig43.png

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There’s nothing wrong with working with less than fully-dried lumber if you account for future wood movement in the design. Just ask Peter Follansbee.

 

wood-handbook-fig43.png

thanks for your input,  instead of "ask Peter follansbee" is there a specific article or interview you would like to share or link to? 

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Here’s Peter’s blog: https://pfollansbee.wordpress.com

And here’s a fantastic book that he cowrote showing how to make a joint stool using green wood. Even if you don’t like the actual piece, the information on using green wood in a project is terrific. http://lostartpress.com/collections/books/products/make-a-joint-stool-from-a-tree

And just in case this might be useful, here’s a link to how I built my Roubo out of 4x4’s. These were kiln dried, but as Shannon pointed out, probably not down to less than 10% due to the fact that it’s construction lumber. http://giantcypress.net/tagged/roubo/chrono

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I never realized that moisture content was such a hot topic!

13 years ago, I built a bench top with construction grade lumber. It is 2" thick and 30"x60". I took no special measures for moisture content (took the 2x8s out of my truck and ran them through the jointer and planer). The bench is still in service in my shop today.

As some have mentioned, it may have worked because softwood is more forgiving than hardwood, or maybe I rolled the dice and hit the jackpot that weekend.

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I never realized that moisture content was such a hot topic!

13 years ago, I built a bench top with construction grade lumber. It is 2" thick and 30"x60". I took no special measures for moisture content (took the 2x8s out of my truck and ran them through the jointer and planer). The bench is still in service in my shop today.

As some have mentioned, it may have worked because softwood is more forgiving than hardwood, or maybe I rolled the dice and hit the jackpot that weekend.

it may not be a "hot topic" but it is one of those things that can differentiate fine craftsmen.  Perfectly dried wood has much less tenancy to move, which allows the craftsman to build something and know it will stay like that or close to it for a long time to come. 

I think eric and I both woke up full of piss and vinegar this am and happened to be in each other's way.  What many  have said is true about mc. Lower is usually better and allows MORE PREDICTABLE results.  Not fully predictable, but more. 

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So with this information, is it a reasonable assumption that wood from a hardwoods distributor has been through the kiln drying process, and thus all that is left is to wait until EMC? Or does this mean that the onus is on everyone to somehow kiln dry their stock?

For example, guild project. I order up ~80bf of Cherry from my local hardwoods distributor. I let it sit in my shop for <x days> before milling it down slightly (not full dimension). Wait <x days> and mill to final dimension, cut and dry assemble parts. What is a reasonable value for x? ...This is starting to seem more like Algebra than woodworking...

Any particular gizmo recommendation for checking the MC, or are they all about the same?

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Unless you go to a timber mill, your local mill is buying kiln dried most of the time. It does not hurt to ask to be certain, but they are selling to customers who want to go right to work. The caveat is that their yard is often outside and open to some weather. I can say that shipped raw flooring usually sits in homes for two weeks here before the hardwood guys come install it. 

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When I buy wood,  I ask.  Not Sally or jimmy that may be working the register but the yard boss that actually knows. 

I think it is reasonably safe to expect that the lumber you are buying had been dried, but I don't expect,  I ask and confirm with my moisture meter.

The reason for letting it sit on your rack a bit, is your microclimate is different from where it was dried.  Was your walnut cut in Pennsylvania, dried in Kentucky, then shipped freight to somewhere else usa? The humidity will proabably be different in your garage than in the kiln. 

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So with this information, is it a reasonable assumption that wood from a hardwoods distributor has been through the kiln drying process, and thus all that is left is to wait until EMC? Or does this mean that the onus is on everyone to somehow kiln dry their stock?

For example, guild project. I order up ~80bf of Cherry from my local hardwoods distributor. I let it sit in my shop for <x days> before milling it down slightly (not full dimension). Wait <x days> and mill to final dimension, cut and dry assemble parts. What is a reasonable value for x? ...This is starting to seem more like Algebra than woodworking...

Any particular gizmo recommendation for checking the MC, or are they all about the same?

If you're buying kiln dried lumber and it's been resting in an environment similar to yours for any significant amount of time...say a month or more...you can take that stock home and be fairly confident to build right away.  Best practice is still two rounds of milling...not always practical on small or rushed projects but on the bigguns try to do it twice.  You'll learn a lot about your stock after the first milling session once it's stickered and stacked and you let it breathe for a few days.  If it stays fairly flat, you're good to go; if you encounter significant movement, you've likely got a problem with either the wood itself or the drying process it's been through.

Buying online is a different story.  If you're in Arizona and you have Bell Forest send you a pack, you better give that stuff some extra time to acclimate.  Same goes for shipping from an arid region to a muggy one.

But still...buying kiln dried lumber decreases risk of major issues or time delays...given that it was properly dried and handled.

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I'd say flip a coin, but I wouldn't put time in anything wondering what the outcome would be.  This reminds me of what an old man told me about a chicken coop he built out of green Sweet Gum.  He said that in about a year, the inside was on the outside.

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To wait or to proceed is really your call at this point, no matter what others tell you. You will have the most experience with the material on hand which will allow you to make the most educated decision. I was milling 10/4 poplar once for a carriage door project that I never finished. Long story short, the material started acting up on me, and I decided to eliminate the material from the project all together and substituted engineered lumber in place of the poplar. First you need to determine material behavior, then make a decision based on what you want the final outcome to be. 

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I think I'm going to do a bit of exploratory "milling and see how it goes.

The plan is to break a test group of lumber down into sizes closer to the final dimension. I'll be needing a lot of boards in the 4.5" wide range. I'm going to cut some of the big 10-13" pieces of nastier stock into about 5" wide sticks opening up some fresh internal to aid in drying. I may do this with 3-4 pieces. I've got about 50bf more than I should be fxin to need. in a few weeks or a month, I'll check them out and observe. If they have stayed straight and dropped mc faster than the others, ill process some more. If they look like a tied shoelace, then I'll never admit it and you will never hear about it.

Sound plan!

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I think I'm going to do a bit of exploratory "milling and see how it goes.

The plan is to break a test group of lumber down into sizes closer to the final dimension. I'll be needing a lot of boards in the 4.5" wide range. I'm going to cut some of the big 10-13" pieces of nastier stock into about 5" wide sticks opening up some fresh internal to aid in drying. I may do this with 3-4 pieces. I've got about 50bf more than I should be fxin to need. in a few weeks or a month, I'll check them out and observe. If they have stayed straight and dropped mc faster than the others, ill process some more. If they look like a tied shoelace, then I'll never admit it and you will never hear about it.

We'll hound your ass Till we find out ?

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ive got a good news bad news thing going on. 

Good News:  I ripped down three of the longest boards in the stack, one from the top, middle, and bottom; these boards were in the first set cut about two weeks before the second batch. upon ripping them in half, I took measurements from all 6 boards. results were  11,11,12,12,12,13.  So good news is that the wood was a bit dryer than I even thought.

Bad news: I'm in terrible shape to be lugging around 9/4 11" wide and 9 foot long boards, my garage space although with the needed machines to do it properly is not set up to mill them efficiently, and finally, I definitely need another roller stand or 2. having only one stand made issue 1 & 2 worse.

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Harbor freight roller stands are pretty good for the price. I would cut the beams to rough length (oversized 6" or so) before ripping or any other milling.

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Yeah steve, that will be the plan once it's time to actually mill down for real parts. This was an experiment to see how the wood will react. Over the next couple weeks. My delta planer is SUPER snipe prone no matter what I do so I have to give it a generous  extra length.

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All of those boards were about 11" with vertu rough edges. , I jointed one edge, ripped it at about 5.25" on the band saw, which was a trip to do alone. One or two more passes on the freshly cut face of the side away from the fence flattened it out for another run to cut the other side off 

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"General commercial practice is to kiln dry wood for some products to a slightly lower moisture content than service conditions demand.  This anticipates a moderate increase in moisture content during processing, transportation, and construction.  This practice is intended to ensure uniform distribution of moisture among individual pieces."  This is from page 13-3 of the Wood Handbook - Wood as an Engineering Material by the USDA Forest Products Laboratory (FPL-GTR-190).  It is 509 pages of nice bedtime reading.  You should be able to find it online for free.

From Figure 13-1 The average recommended moisture content for interior use is 8% in Western California and dips down to 6% in the desert areas.  It is 11% in the South East.  Most of the USA is 8%.

I am not really sure how any of this helps the original poster but it seems people are really really interested in wood properties and this publication will give them a heck of a lot to digest.

If you are wanting to start on the bench maybe the leg assembly would be the place to start.  By the time you get that finished hopefully the boards for the top will have reached a more optimal moisture content.  You could also rough mill them down closer to the final sizes as the board will dry quicker if there is less volume.

 

 

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Harbor freight roller stands are pretty good for the price. I would cut the beams to rough length (oversized 6" or so) before ripping or any other milling.

I second the HF roller stands, with the caveat that the plastic splined screws aren't much good. I welded a couple of inches of scrap rebar to the head of one inch 5/16ths bolts to make T-heads, to replace the originals.  

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I was very disappointed with the HF roller stand. I bought two, still haven't taken one out of the package because the other was such a piece of crap. I couldn't get the foot to stay on, the little metal thing that you screw it into inside the pipe is hard to get on and won't tighten. 

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