Dog hole strip attachment

[Tyler Keniston]

Hi. I'm looking for a little advice on attaching the 'dog hole strip' on a workbench build. Its a strip of square dog holes going onto a 4 inch thick top.

The two questions are:
1) should it be glued to the top over-sized (in terms of thickness) and then hand planed down to match? From my experience, it is near impossible to keep an 8' long board exactly flush to the other board(s) its being laminated to, even with cauls, buicuts, dominoes, dowels, etc. I am installing a benchcrafted tail vise and their instructions seem to have the top all milled to final thickness, then cut the waste away for the vise slot, then glue the dog hole strip and front laminate on. This implies that I cannot attach the dog hole strip prior to final milling of the bench top (it will be going over a jointer and through a planer). It seems also to imply that the strip and laminate be of final thickness when glued. I'm worried if they don't glue on perfect any low spot will require tremendous hand planing on the rest of the top.

2) How to manage squeeze out when attaching the backer (or to bench if not using backer). I have yet to manage glue application enough to avoid squeeze out (plus if there is no squeeze out, then i take it to mean there is not enough glue and the joint is starved). So any tips on clean-up considering the squeeze out will be inside the square holes (4" deep holes too, so not super easy to get into). My best guess would be to get a long Q-tip or similar and use a little water to clean the holes while the glue is still wet. Seems a bit tedious but I can't think of a better way.

Thanks for any tips,

Tyler

[Dave Richards]

Is this an existing top to which you are adding a dog hole strip? or are you making the top from scratch?

You should be able to get accurate alignment if you use horizontally oriented biscuits. You could also gut mating grooves and use a spline. On the side with the dog holes, you'd need to cut the spline into pieces but you'd get the alignment you're after.

As for managing squeeze out, my favorite method is to temporarily clamp the pieces up dry and rub a bar of paraffin along the seam lines. The proceed with gluing. Leave any squeeze out alone until it hardens. Then run a card scraper down the seam line to pop off the squeeze out and scrape off the bulk of the paraffin. A few swipes with a rag and mineral spirits will take care of the remaining paraffin and also expose any spots where glue soaked into the wood. You shouldn't have any of those spots if you get a good layer of paraffin in the first place.

As for squeeze out in the dog holes, I would skip the water and cotton swab. When the glue has mostly set up, you can run an old chisel or sharpened screw driver down the corners to take care of that.

Paraffin is cheap, readily available in the grocery store and a box of it will last you a life time. it's good for lubricating hand plane soles, miter slots, screws, etc.

[Tyler Keniston]

It is a new bench, split top. The main top sections are already glued together but haven't gone through the final milling. I re-read the benchcrafted instructions and I'm pretty sure they have everything milled to final spec and then glued. I just didn't feel like over an 8' span that even careful spline or caul use would ensure a totally flush joint. Even if it goes off in one spot by just a couple thou, that means hand planing the rest of the bench down to meet that low spot where the joint was off... It feels safer to glue over-size, and bring that one strip down to the size of the rest of the bench...

Thanks for the tip about the paraffin, I'll give that a try.

[Peter Aeschliman]

You're right that it will be almost impossible to glue it up flush. No matter what, you're going to have to flatten the top to deal with inconsistencies- it's just part of the process. If you use biscuits and are careful with your setup to make sure the biscuits are placed in the same locations, I think that's the best you'll be able to do.

When you do the final flattening, you will end up removing material and the top will be less thick than the final milling thickness that the instructions call for. But the bench is designed for you to be able to flatten it periodically over the years. The leg vise chop and wagon vise block are wood for this reason.

In other words, I think you're worrying too much. :)

[Alan Schwabacher]

I treated the doghole strip exactly as I did the other strips: no splines, just clamping cauls to help alignment. When it was glued up, I planed it all flat. Ignore squeeze out: it planes off when you flatten the top. The bottom I planed flat only the part that rested on the bearers (it is a split top) so as to leave the maximum thickness and minimize work. I did use winding sticks there to make sure bearing surfaces were parallel.

One thing I'd do differently if gluing it up today is that I'd put ball catches in the bench itself, rather than the dogs. That way any rectangular stock will hold its height as a dog.

[Michael Peet]

Hi Tyler,

When I built my bench I also installed a BC wagon vise and also did it as you were planning - make the dog strip a little thicker and then plane it down. However, Peter is right in that you will probably want to plane the whole surface flat at the end anyway, and periodically in the future. It's not a big deal and it's not too difficult.

As for the squeeze out inside the dog holes, Dave's suggestion about running a chisel down inside is good. I was more worried about glue smearing around inside the holes during alignment. It is more difficult to deal with than neat beads of squeeze out. For this reason I used two short dowels for alignment, but only on this joint.

308448

Mike

[Tyler Keniston]

I probably am over thinking it, as I so love to do (a chronic problem of mine). What I'm hearing is that gluing at final thickness is fine given hand planing, but there is no reason not to glue over sized. I guess I am not convinced at how much hand planing I will have to do considering each half is going over the jointer / through the planer. Assuming I line the two halves up properly, they should be pretty good to go no? I still plan to touch the plane to the top, but I'm really hoping it'll be minimal.

Now that I think of it, I'm not really sure why the strip can't be attached before I pass the halves through the machines, thereby eliminating all this issue. I know in the BC instructions the strip is not attached when the tail-vise cavity is excavated, but I'm not actually sure why. Perhaps it'll become apparent as I start in on the tail vise. ?

[Denis Kenzior]

Here's how I dealt with glue squeeze out and alignment issues. Might give you some ideas

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Align the dog strip to the slab. If you're paranoid, make the dog strip just slightly oversize.
Clamp everything down, re-check alignment
Mark locations for some holes for dowels. I put them straight in the middle of the slab, between the dog holes.
Drill 3/8 hole right through the dog strip into the slab.
Repeat as many times as needed. My work bench was just under 7 foot and I used 3 dowels.
Mask the area with masking tape. Stay off the glue line, but get as close as you can. Doesn't need to be perfect.
Take off the clamps, apply glue.
Clamp the hell out of it
With a good drill bit and good dowel stock, you get extremely good alignment.


Similar setup can be used to glue the final outside piece that joins with the end-cap. You don't want to plane the dog strip too much as you'll end up with your dogs sitting proud.

[Greg Hines, MD]

"One thing I'd do differently if gluing it up today is that I'd put ball catches in the bench itself, rather than the dogs. That way any rectangular stock will hold its height as a dog."

That is a clever idea. I use round dogs, but if I were using square ones, that would be a good idea.

Doc