Workbench - biscuts or not

[Gary Haugen]

I am about to start laminating the top of my workbench. 2 1/4"x 24"x72" maple top. I will be gluing up the top in increments, so that I can use planner to keep the sections flat, with only the final joint being too large to run through the planner. I had planned on using two rows of biscuits to help keep the top level through each incremental stage.

However, in this month's edition of one of the woodworking mags (sorry at work and don't remember exactly which one) the author says not to use biscuits when laminating the top except for the last joint and only then in the cutoff portion.

Is there a reason not to use biscuits in the body of the worktop? I recognize that the dog holes will more than likely cut through some of the biscuits, but I can't believe that will make any difference to the structural integrity of the top.

Appreciate your thoughts.

[Swingman]

Biscuits in the situation you describe, gluing long grain to long grain, will add nothing to the strength of the top. They may benefit in alignment to some degree, but I personally wouldn't bother.

[Barry Lennox]

I just built one, out of FWW, from 2 x 4 pine. Thought about it, but did not use biscuits in the end. It worked out great.

Barry Lennox

[Stephen M]

I did a 3"x24"x78" maple top as 5 subassemblies. You do not need buscuits. Make the subassemblies a little oversize (3/16?), The power plane and (edge) rejoint the subassemblies.

If you feel that you need biscuits to help with allignment when joining the subs together, go for it. Personally, I always fit glue-ups by hand without any trouble. I suspect that alot of folks that rely on bisquits for allignment are using stock that was not recently jointed and is no longer dead-flat. Therefore, the biscuits are "pulling" slightly warped boards into the same plane. With freshly jointed stock, I just don't have a problem adjusting the glue-up by hand.

[mike]

Gary you do not need biscuits. I definitely would use 5/16" allthread thru the center of lamination. 4" from each end , space three or four more in between.Bore 7/16" holes in each piece on drill press, make sure you use a stop on fence. I bore the 4" first on each piece, then next hole on each piece etc. This will keep your holes lined up.Glue up 4 at a time using allthread and clamps. Then thickness plane. Glue up three sections to give you 27" , counter bore outside boards for nut washer , make sure the counterbore is large enough to acommadate socket on wrench.The all thread prevents the top from separating with temperature and humidity changes. If you are using square dogs , cut them first in each edge with a dado or router.Dado is easier if you want your holes to be 3 degrees out of square. When gluing up place dogs in holes to check the holes line up correctly.

mike

[Mike]

[e-mail] (mike) wrote

And what is the purpose of the all thread? It is not needed for strength and adds a lot of hassle.

Mike

[Kevin]

The reason you WANT to use Biscuts is to aid you in the alginment of the pieces. Once you glue the pieces and clamp them, they will shift around. If you put in a few biscuts it will keep everything straight. You won't need them for strength.

Kevin

[todd]

I missed the original post in this thread, but an issue of Workshop Solutions that I just picked up has plans for a workbench where the laminated top uses 1/4" plywood splines between each board.

todd

[Eric Lund]

Every once in a while you are going to need to flatten the top. Eventually, you will plane down to those biscuits. After running the two sections through your planer, it should not be too hard to do one final glue joint and get is nice and flat. You can put a clamp with the joint (across the thickness, part of each clamp on each section) at each end of the glue up, then put your main clamps across the width of the joint. Use white glue and you will have longer to open time to get it right. Remember, the glue joint, even with white glue, will be stronger than the wood.

Cheers, Eric

[Andy Dingley]

Should be just about time to take the 2" boards I started off with and make them into the box to put me in.

[WD]

Mike, I have never come across anyone using allthreads (I am a newbie) as you describe it below. I will soon be starting on my workbench after I completed my mobile saw cabinet.

I am wondering how do you keep all the laminations align since you bored 7/16" holes with 5/16 allthreads and what glue are you using?

Thanks