Roubo lamination disaster

[Daniel Hartmann]

I recently set out to build a split top roubo out of white oak. A friend of mine help me process the oak 2x6s and glue up the tops. After gluing up I left the tops in clamps overnight. The next day (nearly 24 hours) I removed the clamps and found some delamination. This is almost definy due to the 20 degree temps. I think the shop reach 35-40. I tried to pry off some of the boards where the gaps are largest but they seem pretty well stuck. At this point I have a top with up to 1/8" gaps between the boards in spots but there is still enough good long grain glue surface to prohibit a clean detachment. What are my options?? Should I fill the cracks with epoxy? Or should I try to release the glue joint and start over?

[Steve Voigt]

I would try to get the boards apart and re-joint them. Can you slip a handsaw through the cracks? That would be my first plan of attack.
On my first workbench, around 17 years ago, I glued up some edging on a cold night, probably 45° outside and no heat in the garage. I ended up cutting the edges off and doing it over. Cold weather and glue don't mix.

P.S. Take a deep breath. It will be ok, it's just a temporary setback. Get the boards apart, clean them up, and try again when it's warmer.

[Pete Duffy]

Make a groove where the gap is, then inlay a new piece of oak to match (or something else to contrast.) From what I understand, the slab has structural integrity, just unsightly gaps. If it weren't sacrilege in this forum, I would recommend a rou** and straight bit and a straight edge guide.

[Daniel Hartmann]

Correct. It has structural integrity. It's just unsightly.

[Steve Voigt]

Make a groove where the gap is, then inlay a new piece of oak to match (or something else to contrast.) From what I understand, the slab has structural integrity, just unsightly gaps. If it weren't sacrilege in this forum, I would recommend a rou** and straight bit and a straight edge guide.

Correct. It has structural integrity. It's just unsightly.

Uh, how do you know the slab has structural integrity? It's one thing to not be able to pry the boards apart by hand; it's another thing entirely for them to stand up to repeated pounding on chisels, holdfasts, and the like. If it was glued up at near freezing temperatures, I would guess it does not have structural integrity.

[Daniel Hartmann]

They are sound. Each 12" wide by 7 ft long by 5" thick slab weighs about 150lbs. I've lifted one end of each up to head height and dropped them. Hoping the offending board would just pop off. No dice. And they sound the slab makes when dropped gives a nice reassuring tone. As if it were solid.

[Charlie MacGregor]

You might consider finding someone with a Woodmizer or similar to deconstruct for a do-over. Downside is that you lose a little width.

[Noah Wagener]

maybe bolts?

[Brian Holcombe]

I'll pile on, I think it's time for a do-over. If they remain that way their will be some very strange stresses present in the laminations, it'll be a headache later on down the road.

[Brian Ashton]

If it's 5" thick and the cracks run full thickness you could run it over a table saw then flip and run again; standard 10" table saw cuts 3". Then joint and re-glue. Or if the gaps are only near the edge then you could still run it over the table saw and cut a groove that is as deep as the crack and then glue in a filler piece of the left over oak.

To me is sounds like the wood has moved over night in an attempt to relieve some internal stress which I wouldn't be too happy about. You might want to stress test it by taking it inside the house out of the cold and see what it does. Let it stay there for a few days or more then take it back out to the cold shed and see what it does.

Also you were saying the temp was 20 degrees, fahrenheit or Celsius. If it was fahrenheit I wouldn't be to confident in those glued surfaces unless it was cold cure epoxy you were using and especially it it was PVA glue.

[Derek Cohen]

Here's a simpler solution.

If the boards are stuck fast together, then leave them that way. Instead, rout out a groove about 1/2" deep x 1/4" wide at the join, and then glue in a filler piece (take a slice off one side with a circular saw if you want a match from the filler piece). It should end up an invisible fix.

Regards from Perth

Derek

[Jim Koepke]

if the gaps are only near the edge then you could still run it over the table saw and cut a groove that is as deep as the crack and then glue in a filler piece of the left over oak.

Here's a simpler solution.

If the boards are stuck fast together, then leave them that way. Instead, rout out a groove about 1/2" deep x 1/4" wide at the join, and then glue in a filler piece (take a slice off one side with a circular saw if you want a match from the filler piece). It should end up an invisible fix.

Regards from Perth

Derek

Count me as the third to suggest this route.

The space between boards could also be made with a plow plane. If you can get contrasting strips you truly could make a very nice lemon-aide from the lemons handed to you.

Gluing up in the cold doesn't work well. During the cold part of the year my PVA glue is kept in the house.

Any glueing also takes place in the house or wait until warmer weather.

jtk

[Jeff Bartley]

Daniel,
I wouldn't trust a joint glued under cold temps; especially on something like a bench that will hope last beyond your lifetime. Count me as another vote to redo it! I'd try and use the thinnest blade (whether handsaw or bandsaw or thin kerf table saw) and re-joint and glue. I bet those slabs are monsters to move around the shop!

[Chris Fournier]

If you have 0.125" gaps in places I believe that you had problems well before you tried to glue up in the cold. I'd suggest that your stock preparation was not done properly.

You can cover up this glue up as others have suggested. It will take as long as fixing it properly and you still have a very poor glue up that will most likely fail down the road. This is your bench, you'll stare at it for years and this defective glue up will haunt you.

Pull it all apart (find a pal with a bandsaw) and start all over paying attention to stock prep - do a dry run of the glue up before you commit to glueing (min 65 degrees to be safe - materials and air temp).

We all make mistakes so don't feel badly. Make it right with a proper glue up and you are on your way to being a better craftsman with a solid bench that you and others will admire for years to come.

[Daniel Hartmann]

Thanks for all the wonderful replies. A recent development: one of the delams had opened up enough for me to put a crowbar in and sure enough it peeled right off. Looks like a do over is in the works. Anyone in the Nashville area wanna let a fellow woodworker use their jointer?? Not wanting to do all this by hand!