Workbench Top Glue Up

[TomInNC]

I am working on the hybrid Roubo, and I will need to glue up the bench top soon. In the past, I have done panel glue ups just using clamps and cauls. When I have been careful, I haven't had to do too much work flattening after the fact. In the project videos, Marc uses a domino (which I don't have). He suggested using a spline instead. I also have never used splines for a glue up. The boards that will be used for the top will exceed 3.5 inches, and as I understand it, just for alignment I would want at least 2 splines per board. Since I have (1) never made splines and (2) there would be many, many splines, I am concerned that the likelihood of me making an error that compromises the flatness of the panel would far outweigh any (potential) alignment benefits if I happen to get things right. 

Do any of you have experience using splines to glue up boards this wide and long? Is this inadvisable for a beginner?

 

 

 

 

[Chestnut]

Question. Do you have a bit of extra thickness and means to flatten the slab afterward? If yes to those I'd just use clamps and cauls. If no i still feel likely that your goign to need to flatten the top again after glue up even if you use splines or dominoes. I did on my bench top and I used dominoes.

An alternative to the spline would be to get a biscuit slot cutting bit for your router and just cut some biscuits in. Still likely that you'll need to flatten after this step.

Another alternative would be dowels. Still likely to need to flatten after this step.

Otherwise think of a spline like making a frame and panel. The panel is just so small the frame wraps it on all sides.

I don't have the hybrid roubo build just the regular so I don't know what compromises Marc made for flattening.

[TomInNC]

I don't have the plans in front of me, but I know the dimensions for the height of the top were oversized a bit (maybe 1/4 inch?) to account for the flattening. 

When you glued your top up, did you do it all at once, or did you proceed in sections? I am working with dimensional SYP, and I am guessing I will have 8 boards for each part of the split top. I'm a little concerned that the glue will start to set while I am still applying it, even if I use something with a long set time.

[Chestnut]

I did my top all in 1 go. From the MANY episodes of woodtalk that mention ow long it takes to make a work bench I was always confused. I guess it's typical for people to glue 1 board on at a time. That seems like it'd just take way too much time.

If you have a way to lay all the boards set the boards side by side and pour the glue on all of them and use a trowel or shim or something to spread the glue. Getting glue on 8 boards and in the clamps should be 10 min tops.

[JohnG]

Take any restrictive nozzle off your glue jug so your can pour a lot out quickly, grab yourself a brayer, and you can roll it out very quickly. I laminated 2 sheets of ply 3’x7’ this way and had plenty of time. Or any thin scrap piece of wood works well as a blade to spread it out. 


 

[wtnhighlander]

How you glue the laminations also depends on how many clamps you have in the necessary size. If you only have a few longer clamps, glue in stages to build stiffness at the biginning, so fewer clamps are needed to distribute force in the final step.

As for alignment, I feel that splines are super simple if you have a tablesaw, or a slot cutter for your router, as @Chestnut suggested. Just remember to register all of the cuts from the edge that will become the top face of the slab. They don't need to be very large or deep either, since they are just an aid to straightness as you glue and clamp.

[TomInNC]

Thanks for all the suggestions. I was just looking at the lumber stack. I initially thought I would be able to get 3 boards for the top out of 1 2x12. I forgot about the stock I will lose when I eliminate the rounded edge when I made these calculations, so now I have some decisions to make. 

The plans call for initial cuts for the top at 3.75'', with the final thickness getting down to 3.5'' for the top. Once you account for lopping the rounded edge off and the kerfs, if I try to get 3 boards out of 1 2x12, the widest I can get will be a hair over 3.5. So I can either (1) cut the 3 widest boards I can out of the 2x12 and hope I don't lose too much to final flattening of the top (2) cut 2 boards out of the 2x12, glue the off cuts together, then cut the remainder of the boards or (3) go back to the lumberyard and end up with a ton of waste.

Right now I am leaning towards option (2). Aside from the annoyance of having to glue up more boards, do you see any downside to this approach? 

 

Speaking of this issue, I feel like I frequently end up gluing stock together towards the end of projects so that I can get the final few parts out. Is this pretty common? Or do I just need to get better at planning?

 

 

 

[Mark J]

29 minutes ago, TomInNC said:

Once you account for lopping the rounded edge off and the kerfs, if I try to get 3 boards out of 1 2x12, the widest I can get will be a hair over 3.5.

Maybe I'm misunderstanding the problem, but could you cut the 2 x 12 into 3, then flip all the boards such that the rounded corners are on the bottom where it won't matter?

[Chestnut]

1 hour ago, TomInNC said:

cut 2 boards out of the 2x12, glue the off cuts together, then cut the remainder of the boards

This. If you can get 2 4" wide boards and have 3" left over, just glue some scraps to make that board wider, then stick it in the middle so the only way you could tell it's laminated is by looking at the end of the bench.

I did exactly this with my bench. Even went so far as to have large voids in the middle from wane and board defects. Maybe some day in the distant future some museum will X-ray my bench and find the crap material I used.

My pine bench I just didn't remove the rounded edges and put them down like Wtnhighlander mentioned.

[wtnhighlander]

Don't fret too much about the thickness of the top. With a soft wood like pine, you will very likely have a much thinner top in a few years, as you must plane away the worn surface more often. Mine is a shade under 3" now, still grabs a hold-fast without problems. The advantage of softer wood is that it is less likely to damage things dropped upon it, and seems to be more "self-healing" from knife slices, screw holes, etc...