A different option for gluing up a slab

[Scott Winners]

I went back and looked over my workbench build thread here. I already had the slab glued up when I opened that thread, and I don't remember seeing anyone else use this method since.

I glued up my benchtop in one go. All the pieces, all clamped together with wet glue on every face and it was finished. I see lots of folks gluing two pieces together and then pairs and so on, and it works for folks. I am not saying it is a bad thing to do, I just don't have that kind of patience.

Starting out all my F clamps, my big ones, could clamp two pieces of construction lumber face to face, but not three. I looked at F clamps at the homestore. I did buy one 36 inch F clamp from team blue, it was about $30. The bar on it bows pretty easy when trying to clamp something 24 inches wide. I looked at Bessey's at my local hardwood shoppe, I can't afford those.

So I went back to the home stores. I bought some 2x8 construction lumber, and a bunch of 1/2 diameter all thread with washers, fender washers and nuts to match. I did have to get some 6 foot lengths of all thread to make 3 foot pieces from, but my tap and die set goes up to 1/2 anyway, and I got a hacksaw, so no worries. And I got a 5/8 drill bit already.

So I cut the 2x8 a bit longer than my bench top, and drilled two lines of 5/8 holes in the two pieces of 2x8. I used a pair of sawhorses leveled to each other to hold the future slab up off the ground, clamped it up dry, took the clamp back off, spread all the glue, clamped it back together and left it in the clamp about two or three days. Worked fine.

I do like to get some wax paper between the wet glue and the all thread, easier clean up that way. Also possible to drive wedges or shims inbetween the all thread and the glue up panel to keep the panel flat. This system is not as fast as Bessey's, but with a dry clamp up before the glue bottle gets opened I can generate a right lot of clamping force with this inexpensive system before the glue sets.

The 2x6 in this picture with the holes in it is for gluing up thinner panels than a benchtop, but I am using the same all thread. I expect to be gluing up a moderate panel in the next week or two, I will try to get a picture of the thing in use before this thread gets too long in the tooth.

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[Scott Winners]

Actually, have one in my phone of the same all thread clamping a small panel glue up from about a year ago. Looks like the glue bottle hasn't been opened yet.

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[Jim Koepke]

Where there is a will, there are ways.

jtk

[Joe A Faulkner]

Nice bit of innovation and economizing Scott. I was 30 plus years into wood working when I built my first workbench, so I had amassed sufficient pipe and parallel clamps to laminate my top using clamps. I had one kitchen cabinet build, accouple of large cabinets and bookshelves under my belt which served as good excuses for incrementally acquiring additional clamps. Looks like your all thread screws and 2x8 jaws can be repurposed for various clamping tasks. Once you get your bench done, you can use holdfasts, dog holes and wedges to clamp parts. You might want a film finish on your bench top though so glue can be easily scraped off.

I am curious, how many all thread screws did you wind up making? I was just pricing 3/4” threaded black pipe and was a bit surprised to see the price for 10’ pipe is $24, and 3/4” pony clamp hardware going for nearly $15 per clamp. At those prices, it can be hard to invest in a large quantity of clamps in one purchase, especially for the hobby craftsman. Clamps just are not as much fun to buy as saws, chisels, planes, axes and related edge tools, but they are nice to have when you need them.

[Ben Ellenberger]

This is perfect timing. A friend wants me to make a 6’x6’ bookcase, and my longest clamps are 48”. I’m trying to decide whether to buy clamps or make something that I can use for clamping.

I like your idea. I was thinking of different ways I could generate clamping force with wedges, but your solution is better than anything I thought of.




…. I just checked and it appears 6’ is the longest length they stock in Home Depot. So about 5’6” is the longest clamp you could make with this system, unless you find a specialty supplier.

[Scott Winners]

My bench has MMXVIII carved in the front stretcher so coming up on 4 years old. Glad I labeled it I would have guessed three years old. Any road, as the original film finish came off the top with flattening I haven’t replaced the film. I did use equal parts blo varnish and thinner when new. It is enough to keep the cat from using the bench as her personal sharpening station prefer a naked top my self.

I have used a lot of quarter inch all thread for smaller custom clamps and looked to online specs for how much torque could be applied before settling on half inch all thread as more than adequate and readily available. I have ten pieces, each 36 inches long, in the shop today. My existing bench is 48 inches long, I will plan to have 20-30 pieces ready to go when gluing up an eight foot bench top slab.

for clamps greater than six feet you might look at union nuts. Probably not at the home store, but that could allow you to attach two pieces of all thread end to end for greater length. Might lose some total available torque as well. Alternatively steel cable and some turnbuckles with sacrificial hardwood guides. Not zinc turnbuckles, and there are rules about those wee saddle nuts as well, never saddle a leg or something like that.

witht he all thread the rule of thumb I remember is the bolt should pass through the nut for at least the thickness of the nut for maximum holding power. Then washers and the 2 x pad, so sure, 5 feet 6 inches is a reasonable nominal max for six foot all thread.

another possible handy clamp for a large case are the ratchet straps or tow straps like are used to hold a boat or an atv down to a trailer. A set of four rated 800# each is likely under $20 at Walmart or a sporting goods store, you can spend more for higher ratings, longer lengths or metals that are salt resistant. Probably a scrap of corrugated cardboard under the mechanism to protect your finished surface.

[Jim Koepke]

A loop of rope twisted with a stick can be an effective clamping device. (aka Spanish Windlass)

Think of the loop of twine at the top of a bow saw used to tension a blade.

Springy pieces of wood can be bent between an overhead beam against a work piece to apply clamping pressure.

Lots of ways to drive to pieces against each other.

jtk

[Michael Schuch]

Nice glue up technique.

Did you joint the faces of the boards flat then run them through the planer before gluing them up? Or did you just use the factory milled faces of the boards?

Now that is is all glued up how to flatten it? The last work bend I built I was able to take the top to the production shop where I purchase a Dewalt RAS from and they put it on a wide belt sander that flattened it in a few passes for $50. I don't live there any more. I know I could probably purchase and learn to use a plane properly for the job but I would worry about how flat the surface actually is. I was thinking about building a sled for a router to ride on that would allow me to use a router to get the top pretty flat.

[mike stenson]

…. I just checked and it appears 6’ is the longest length they stock in Home Depot. So about 5’6” is the longest clamp you could make with this system, unless you find a specialty supplier.

Get some couplers and some 1' pipe. Works quite well.

[Jim Koepke]

This is perfect timing. A friend wants me to make a 6’x6’ bookcase, and my longest clamps are 48”. I’m trying to decide whether to buy clamps or make something that I can use for clamping.

I like your idea. I was thinking of different ways I could generate clamping force with wedges, but your solution is better than anything I thought of.

…. I just checked and it appears 6’ is the longest length they stock in Home Depot. So about 5’6” is the longest clamp you could make with this system, unless you find a specialty supplier.


Get some couplers and some 1' pipe. Works quite well.

Mike, Ben may be referring to the all thread. If that is the case your idea of 'couplers' is still good. There are standoffs or long through nuts that could extend the all thread > Such a long URL (https://www.lowes.com/pd/Hillman-1-Count-0-500-in-Zinc-Plated-Standard-SAE-Regular-Nut/3013471?cm_mmc=shp-_-c-_-prd-_-hdw-_-ggl-_-LIA_HDW_126_Fastening-_-3013471-_-0-_-0-_-0&ds_rl=1286981&gclid=Cj0KCQiAtJeNBhCVARIsANJUJ2FoWfBeZ3Jue67NlF-QLrS7CwAO_bJq_-BfxPWMth4lulbeRenunHQaAuu5EALw_wcB&gclsrc=aw.ds) < To what ever length needed.

Ben, most woods start to buckle or bow under the weight of books at three feet. You may want to have a central support in your bookshelf project.

Finding the nuts was enough for me. Someone else can find a link to the bowing of various woods for shelves.

jtk

[mike stenson]

Yea, those coupler nuts are still used in hanging cable ladders. So, should hold for a glue up :)

[Daniel Culotta]

Now that is is all glued up how to flatten it?

Jack plane across the grain to get everything even, jointer plane along the grain to get everything flat. This will make the surface plenty flat enough for a work bench. SO much less fiddling than the router sled option. And, as long as the top doesn't start in too bad of shape, it should take an hour or less.

[Jim Koepke]

Jack plane across the grain to get everything even, jointer plane along the grain to get everything flat. This will make the surface plenty flat enough for a work bench. SO much less fiddling than the router sled option. And, as long as the top doesn't start in too bad of shape, it should take an hour or less.

An hour or less? Maybe for you young'uns.

Post #13 in this thread shows one way to check for flat over a large surface > https://sawmillcreek.org/showthread.php?272588

jtk

[Michael Schuch]

Jack plane across the grain to get everything even, jointer plane along the grain to get everything flat. This will make the surface plenty flat enough for a work bench. SO much less fiddling than the router sled option. And, as long as the top doesn't start in too bad of shape, it should take an hour or less.


An hour or less? Maybe for you young'uns.

Post #13 in this thread shows one way to check for flat over a large surface > https://sawmillcreek.org/showthread.php?272588

jtk

I like the string method for checking for flatness. I have a radial arm saw table to make and I am considering making a construction lumber slab for the table but flatness will be key for accurate cuts, especially dados. I will have to figure out what types of planes I received from my father and what I would need to purchase. I am a little concerned about making the top surface planer to the bottom surface. Thank you for the input.

[Robert Engel]

Yes, you get lucky sometimes.:)

[Scott Winners]

Nice glue up technique.

Did you joint the faces of the boards flat then run them through the planer before gluing them up? Or did you just use the factory milled faces of the boards?

Now that is is all glued up how to flatten it? The last work bend I built I was able to take the top to the production shop where I purchase a Dewalt RAS from and they put it on a wide belt sander that flattened it in a few passes for $50. I don't live there any more. I know I could probably purchase and learn to use a plane properly for the job but I would worry about how flat the surface actually is. I was thinking about building a sled for a router to ride on that would allow me to use a router to get the top pretty flat.

At the time I only had a number 4 Bailey that still needed some work. I used lots of glue, lots of clamping force, caught lots of squeeze out with a drop cloth, but I glued up the 2x4 without doing any surfacing operations to them after purchase. I did leave them stickered in my garage for about two weeks before glue up to make sure nothing was going to move too much. That part went fine. I used the facotry milled faces of the boards at the time because I did not have the tooling to improve them.

Once it was out of the clamps I bought a shiny new #4 from the home store thinking it might be easier to fettle than my vintage #4. After much reading here and frustration there I ground the iron on the new blue plane to about a 3" radius crown and opened up the mouth a lot. Pretty agressive scrub plane, it can shoot chips feet into the air. I treated the slab like a board, winding sticks, scrub plane, once it was down to flat and scalloped I went with the grain to take the scallops out. Then flipped it over and repeat.

I think the key to good enough flatness is an agressive scrub plane. Remember my top still had the rounded corners on all the 2x4 glued into the slab. Remnants or the roundovers are still in my top, I don't see any reason to take more off the top, it is not like I am assembling miniature gyroscopes for NASA. Also, I didn't take every scallop on the underside of the benchtop off, just got to down to where I felt good about the areas around the legs providing good contact.

For my 24x48 top (Doug Fir) with an agressive scrub and beginners luck on glue up square and true I recall it took about two hours with the scrub to get to flat and ready to start smoothing, per side. There was chasing of the work around as I had the slab F clamped to a couple saw horses. I didn't bother smoothing the scallops out of the finished top until the entire bench was assembled. That weighed a bit more and scooted around the floor a lot less.

I guess flatness is possibly a rabbet hole. One the one hand chasing perfection or visualizing perfection is a potentially noble or worthy thing, but you can also bang out a couple birdhouses and then maybe take on a small firewood rack or a small elegant trashcan before you get to a point where you can say "My bench top is not flat enough for this project to some out good" and plane it some more flatter so you can make bigger more complex things.

For my RAS I have a folding stand for it, I think labeled "MSUV" for miter saw utility vehicle. All folded up it can stand in a corner and not take up too much room, but unfolded out in the driveway the side rollers for the work to ride on span about 10-11 feet and can be easily leveled to the cutting surface on uneven terrain.