Bench Top Advice

[Jeff Posten]

I struck out with local lumber yard looking for fir 4x4's and 2x material, and happened across some 8/4 ash. I picked up 60bf, and was planning on laminating them together on edge for my bench top.

All are 8/4 x 6" x 96" rough dimensions. Initially, I was thinking of ripping them in half lengthwise, and standing them on edge, to end up with a 2 1/2" or 2 5/8" thick top, by 24" wide. However, after looking through a lot of books and blogs it seems like most recommend about 3" to 4" for the thickness. I know ash is very strong, and a 4' span between my legs is most likely well within acceptable deflection rates, but now I'm doubting myself, and wonder if I would be better served going the split top route by ripping them to 4", and gluing up a 14" main slab for the front. I was actually thinking of doing the split top regardless as I live a semi-nomadic life at the moment. Thoughts/advice?

Additionally, these came in at about 15% RH, which is slightly more than I was hoping for, but think it will be workable. Opinions?

Jeff

[Brian Holcombe]

Jeff,

I would certainly do a split top, its much easier to handle 14" pieces over 28" pieces if you need to take your bench apart (which you will eventually do for one reason or another). I would stick with 4" thick for the top, it'll save you a lot of grief in the long run, it will remain flatter and will be easier to flatten without concern for making it to thin. These things all move over time and especially after the initial build, so they will require an occasional flattening over the life of the table.

Ash is a great choice for this.

[Jeff Posten]

Brian, thanks for the recommendation. I strongly agree that 14" is much easier to lug about. I've been doing some additional reading about the MC... Wasnt sure it was dry enough and a call back from the millwork business i dropped it off at to be processed confirmed. He said he felt it was still too wet to be dimensioned.

So now I have to decide if it's worth waiting for this stuff to lose another 4-5%, or if I should begin another search for material. My basement is in the low to mid 50's, with a RH of about 35% right now. Any experience how long it would take to get the rest of the way?

[Brian Holcombe]

I find often times the initial move for new lumber is always to shrink, summer or winter. I assume it's always wetter than it will end up after being put to use, especially in the winter. My bench top has shrank about 1/8" from where it originally sat.

Plan the entire build, soup to nuts, before you do the glue up. Square bench dogs among other things are easier to cut into a bench before it's been glued.

[David Weaver]

I'd personally be fine with a 2 1/2" thick bench top. I can't imagine any reason it wouldn't be acceptable unless you had hardware that was specifically designed for a given thickness.

Build the legs stout and build a cabinet below it with a gap, and there will be plenty of mass and strength.

[Bob Lang]

Ditto. My ash top is just under 3", 2 1/2" or even 2" works just fine. The current trend of thicker is better is more about fashion than it is about function.

Bob Lang

[Chris Griggs]

I agree with Bob and Dave. 2 1/2 is just fine. The only reason the bench top I'm working on now is so thick is becasue that's how thick the lumber was after dimensioning and I decided to just go with it for fun. Too thick you can start to run into problems with some holdfasts. I think the one I'm working on now is coming in at a little over 4 1/2, and I do have some concern that I won't be able to secure my holdfasts on thicker work pieces.

I think if I was building a bench from the ground and buying the lumber in what ever dimension I wanted I would go for somewhere between 3 and 3 1/2, but since you are all set to endup with at 2 1/2 to 2 5/8 I would just stick with the original plan. I don't think there is any functional reason to go any thicker.

[Judson Green]

Do you know the history of your lumber? When it was harvested? How long its been air drying?

You may want to bring a chunk of this lumber in your warm living space. Let it warm up for a day or so and then retest it. I think cold lumber can give higher readings.

Swear I read somewhere that air dried lumber is usable in the 10-15% range. That kiln dried is dried down to 5-10% range expecting it to equalize higher after its been taken out of the kiln.

Might warrant a lengthy Google search.

[Jeff Posten]

Thank you to all who have replied.

It was harvested two years ago and has been stickered in a barn attic. I went up there to retrieve it and I'm not sure how much air flow there was up there, and it's been a cold-ish winter (in my west-coast-born opinion) here, so those two may have combined for a higher reading... The millwork place said he measured it around 16-20% in spots, and although I didn't see his meter, based on his planer and jointer size, I would trust his measurement was more accurate than my Wagner 205.

I've talked to the original seller and he's willing to take it back no problem. The mill thought that if I stuck it in a makeshift tent with a heater, fan and dehumidifier I may be able to get it down to acceptable tolerances within a month or two. Unfortunately, being active duty, I'm not able to set down roots and wait for things like I wish. I always feel rushed to get up and running as quickly as possible to get building.

Again, thanks so far to all who have offered thoughts.

[Judson Green]

2 years in a barn sounds good to me. I think ash dries reasonably quickly. I'd chance it. A book of mine "A Natural History of Trees" says ash should have a cubic foot weight of 39-41 pounds dry, unfortunately it gives no MC. Perhaps you could some calculating.

[Jeff Posten]

Judson, I will do some figurin' and get back to you. I did remeasure a few sticks and discovered that one side reads higher than the other. I get pretty consistent 14-15 on one side, and 17-18 on the opposite. Again, basement was at 53 degrees and 31% RH. I was willing to see what I could do with some heat and hair if it was in the 14-15 range, but think waiting for 18 may stretch my patience a little.

Jeff

[Jim Matthews]

Have a look at Josh Finn's design.

You can knock one together, quickly and get crackin'.
The sawhorses will travel well, and the tops are disposable.

Not the classic design you long for, but it's a place to work.
http://www.woodfever.net/2009/12/new...completed.html

FYI - I'm near the Navy town of Newport, RI.
Nobody really understands the turmoil you DoD guys endure, moving so often.

I hope you get to put down roots, where you choose.

[Joe Bailey]

Jeff
Good luck with your project
More importantly - thank you for serving.