I actually read it as 40%, as I *knew* you were right!

Summers can be quite humid here too; but with the A/C running in the shop during the hot/humid months, I expect it won’t be too high. I see an almost constant trickle of condensed water, so the unit is taking out some of the moisture.

The interesting part about the new monitoring system is that it keeps in memory the humidity highs and lows – this will help if I forget to look at it for several days.

Just saw your reply. Sounds like a good plan to see what the humidity is doing.

Just an FYI…it looks like I made a typo in my previous comment. I try to keep my shop at 40% all year long not 4%. It gets higher in summer and sometimes dips a bit lower in winter, but summertime is the season that’s harder for me to keep consistent.

–Mark
The Craftsman’s Path

Indeed, someone I consulted also suggested that the wood “…may have been wetter than it should have when it arrived on our shores…”

In my most recent post I show the hygrometer I ordered and received just today, to monitor relative humidity in the shop.

I will post results in several months. At that time I hope to also have some practical suggestions.

I too am surprised that the bench seemed to move as much as you showed with the straight edge. Especially if it is quarter sawn stock.

I know that when I made my bench I had flat sawn stock that I ripped and then flipped on edge before gluing it into slabs (effectively creating quarter sawn stock) This should cause the movement to be along the thickness of the top and keeping a relative uniform thickness. I guess it’s possible that in your bench a few of the out side boards were not as dry when it was built – so, now they have shrunk a bit more than the others.

I would agree on monitoring the relative humidity in the shop. I keep an eye on mine (basement shop) and I try to keep it at about 40% or so all year long. During the winter this is easier it’s the damp summers that require dehumidification.

Keep us posted on what you find out!

–Mark
The Craftsman’s Path

Note: I made a minor edit, to correct the RH to 40% (from 4%) —— Al

In discussing this with various people, the issue of monitoring humidity in the shop came up repeatedly. Great minds thinking alike!

First: Monitoring the humidity. This will lead to some sort of action, depending on how severe the swings are, both Winter and Summer.

So, high on my priority is to get some sort of hygrometer. As inexpensive as they are, I should have bought one a long time ago.