Spruce lumber bench split; repair suggestions request

[Warren Mickley]

The problem is not the moisture content at time of building. The problem is the top stretcher keeping the top from shrinking and swelling with the seasons. If you had the top quite dry when built the stretchers prevent swelling. So instead of expanding the wood gets compressed. Then when the humidity falls the top is narrower than originally. I would rip the top where it is cracked and reglue. Then enlarge the holes in the top where there are leg tenons (at the back) so that movement can occur.

[William Fretwell]

Bill Howes did a thread on “Spruce workbench, lessons learned” back in December, it may be of some use to read it.

[Rob Luter]

.... I would rip the top where it is cracked and reglue. Then enlarge the holes in the top where there are leg tenons (at the back) so that movement can occur.

This. I have first hand experience. It hasn't happened to me since.

[Jim Clendon]

Hi William,

I have searched "Bill Howes" as well as "Spruce workbench, lessons learned" in the search bar without success... Perhaps I am approaching the search incorrectly...
Capture.PNG

[William Fretwell]

Look on page 13 of Neanderthal that is where it is today.

[Pat Barry]

The cracks all seem to be what I would term delamination, not cracks in the wood itself. My take is that more of these may develop over time. I would attempt to fix by injecting glue and clamping - if that works, great.

[Robert Engel]

The cracks all seem to be what I would term delamination, not cracks in the wood itself. My take is that more of these may develop over time. I would attempt to fix by injecting glue and clamping - if that works, great.

Yes!! + what Rob said. I think what has happened is as the wood continued to dry, the top shrunk width wise and the weakest point gave. I think its most likely due to the base attachment not allowing for movement rather than MC.

Further inspection would be needed to confirm this. But I would say remove the top from the trestles, fill the cracks with epoxy and see if you can clamp it out. Or even better, rip the top down like Rob said.

If you can't clamp it, the epoxy will stabilize the gap.

Re-evaluate how the top is attached and be sure to re-attach to allow for movement.

[James Pallas]

Don’t forget about those legs. If the mortises are tight legs that size can generate considerable pressure along the line of the mortise cut.
Jim

[Pat Barry]

Some have suggested the crossrails, which are not going to shrink lengthwise, as compared to the top aceoos its width may be a cause. Maybe, but that explanation doesn't obviously account for all the delaminations I see. The root cause was likely either insufficient glue, not enough clamp pressure, or surfaces that were no amenable to glue adhesion. This may be as bad as it ever gets. If so, I would not discount simply filling the gaps with epoxy because I think this outweighs having large gaps which will continually catch dirt, shavings, sawdust, etc.

[Matthew Springer]

>My wife and daughter were out of town for 4days and climatization could not be achieved. Considering kiln dried spruce is 19% when it enters the market, 15% was terrific for my last minute procurement.
A word of encouragement: We've all been there. Or at least I have. It's better to do the work when you can and hope for the best than to not do it at all.

I just grabbed a bunch of 4x4 and 4x6 from my local big box store for a pair of Japanese style sawhorses. Planed em all down by planer then hand planed smooth. Then had the kids come back to town and let everything sit for 3 weeks until I could get back to it. I had rhombuses out by almost 1/4 inch at the corners and everything had twisted. But that's the only thing I could have done. They are still awesome and were a lot of fun to build.