Acclimating Wood

[tablesawtom]

What I find interesting is the boards on sight for a long while in the shop are at 10-12 percent and the new boards are closer to 8% MC.  The corporate office from where I get my wood is in SLC Ut so it is even drier there so it is possible the wood is even drier than normal.

This wood is to be built up to a butcher block for a Ruobo style bench.  If I could mill it flat then cut them to width and mll up the butcher blocks in a day, would the butcher blocks be safe, meaning not likely to split?

Real butcher block is end grain, but I am assuming you mean a laminate glue up something like this. By the way you are looking at a top that is 8 foot long and a little over 24 inches wide and it has yet to see a hand plane and it is flat. 

   

I am building a Moravian Bench at the present. This is what my glue up looks like so far. I have changed my mind about the top and it will be a split top instead of the traditional wide tool tray. So you are seeing both sides being glued and processed at the same time. I glue a board on each side and that is how it grows. Note no gaps in the seams , no places that didn't come together, just a nice flat surface.

   

   

Here on the bench that I actually use for a bench is the bottom part of the Moravian Bench.

   

And here is a picture of the top of my work bench that is at least 10 years old and still just like it was the day I did it, except for every one in a while a few strokes to fine tune it.

   

What the others are saying is correct from a laboratory point of view. But if you follow that reasoning, you will always be worrying about moisture content of the wood which will never be prefect and you will go no farther. They have been building Museum quality pieces for thousands of year and none of them even had a moisture meter. I have been working wood for over 50 years and I still do not have a moisture meter. Fact if you use wood from two different trees then you will get different densities and they will take on or lose moisture differently. When is enough enough?  

I have written more on the subject here than I ever intended to. I have posted pictures to back up what I have said. So to you I say, don't talk about it, do it. Build the glue ups and get on with your life.

Tom

PS If it is kiln dried I do not worry about moisture, the kiln took care of that. Moisture does effect size so you have to build with that in mind. Air dried is a different story, takes on and looses moisture differently, but I don't think we are dealing with air dried

My advise, because you are asking for advise, is to stop worrying and just get to building, your wood is acclimated enough. I bought wood yesterday and I will be rough sizing today. If there is a split it can continue so cut it off after the split and you will be fine. I do not worry about acclimation if it is kiln dried. It will be there by the time you get the project built. Remember time in the shop is really a few stolen hours

Tom

[jteneyck]

Excellent advise Tom.  I've only been at this for around 40 years or so.  I look at wood from an engineer's perspective because that's what I am.  The OP probably has a lot less experience than either of us.  Your approach is absolutely fine; buy wood, work wood, let air circulate around it, correct any problems and then glue it up.  Some of your comments, however, were incorrect and I felt the need to challenge them, not to prove I know more than you or anyone else but to help the OP and others understand why wood behaves the way it does in response to changes in moisture.  

My personal strategy for working wood is just a little different than yours:  buy (or mill and dry) wood, measure the moisture content, work wood immediately or wait for it to reach EMC with my shop, let air circulate around it, correct any problems and then glue it up.  Knowing the moisture content helps me avoid cupping and bowing when resawing thick stock, and joints that don't stay uniform in glued up panels.  You are buying lumber from a local source and the RH at their warehouse likely is pretty close to your shop most of the time.  The OP is getting lumber from someplace where the RH is substantially lower than at his shop, at least at this point of the calendar.  He's more likely to have problems with that wood unless he has a good strategy for how to use it.  

You are correct that people have made furniture for thousands of years.  Some of those pieces have survived but many did not.  When central heat came to be the pieces made with poor understanding of how moves with MC self destructed.  Only the ones made by people with a good understanding of how wood behaves are still here for us to enjoy today.  

John

[tablesawtom]

From a job shop Tool and Die Making prospective, Steel also moves. And one can work in in such a way and to allow it to happen. It can't be prevented from happening because it is going to happen. Cold Rolled Steel ( CRS)l is the worst. Moisture does not come into play yet it moves. Heat and cold do effect size. Moisture effects size in wood. Granted a lot of moisture on one side of a board and none on the other will effect the board but that is not the case here. You mentioned a glued up panel. Every one knows that you are supposed to alternate growth rings in a panel. So now when it bows one gets a wavy panel.  You  mention Re-sawing, but he is not re-sawing he wants to make a laminated bench top. 

Growth rings in wood want to straighten in wood and there nothing you can do to stop it. Some of my ash boards are 12 inches wide and I have riff sawn wood, in the flat sawn boards and how that board is broke down will effect how the wood behaves not moisture. As far as a few percentage points of moisture goes,  go pee in the Mississippi river and see how much it raises the water level. 

If he has to ask if he can work his wood and how long does it need to acclimate, then everyone that clings to the only reason a board moves is because of moisture does a lot more harm to a less less experienced wood worker than telling him to go for it. 

Now I posted pictures of wood hanging on hooks with all six surfaces exposed, to take on or expel moisture. I hung it for a week even before I started to flatten. When is it enough to stop worrying about moisture and and get on with building.   In fact I posted pictures to back up everything I said. The quality of the work and process can be clearly seen and understood by what is made, pictures.  And I forgot to say that wood next to a concrete floor leave something to be desired. Concrete draws moisture. No body mentions that. And he has to step over it. great safety practice.

Obviously I disagree with you. And in closing, some pieces remain to this day and some don't. Application, Application, application and not all craftsman were created equal.

Tom

[jteneyck]

Tom, I think I mentioned at least twice that I agreed with your approach.

I hope the OP and others benefited from the discussion.

John

[FrankAtl]

Personally, I enjoyed the discussion between Tom and John and although I've been woodworking for 35+ years, I learned a few things. Thank you for that!

[jteneyck]

Let me explain what I meant by "joints that don't stay uniform in glued up panels."   If you edge glue boards together, identical in every way except average moisture content, the joint won't be flush after the boards come to the same moisture content.  This also can happen with boards at identical moisture content but with different grain orientation, when the RH changes.  I'm sure many of you have felt panel joints a week or month or year later that weren't as perfectly flush as when you first flattened or finished it.  These are two of the potential reasons why.   

John   

[EdL]

Let me explain what I meant by "joints that don't stay uniform in glued up panels."   If you edge glue boards together, identical in every way except average moisture content, the joint won't be flush after the boards come to the same moisture content.  This also can happen with boards at identical moisture content but with different grain orientation, when the RH changes.  I'm sure many of you have felt panel joints a week or month or year later that weren't as perfectly flush as when you first flattened or finished it.  These are two of the potential reasons why.   

John   

Been quietly watching, waiting for (points up) that post.

Thanks John


Ed

[tablesawtom]

John, I do understand what you are saying, and I agree and disagree with what you are saying. What you said does explain a few thing to be true. I have to be gone all day so I will write on the subject tonight. It seems others are paying are enjoying our discussion and paying attention. When I was teaching at the community collage level I was at a conference and the presenter charged everyone in the group to try to pass on all the knowledge you have learned over the years to someone else. So that is why I am writing here. I hope that is what both of us are doing here.

Tom

[photobug]

Real butcher block is end grain.

Only if you are a woodworker or married to one.  My wife is a professional chef, went to culinary school, the only reason we have an end grain cutting board is that she is married to a woodworker and I made her one.  The other 4 commercially purchased wooden butcher block surfaces in my house are edge grain.

[MichaelMouse]

Only if you are a woodworker or married to one.  My wife is a professional chef, went to culinary school, the only reason we have an end grain cutting board is that she is married to a woodworker and I made her one.  The other 4 commercially purchased wooden butcher block surfaces in my house are edge grain.

A former meatcutter will tell you that endgrain cutting blocks are used because they self-heal and put less splinters in the food.