I have built 18 work-benches since 1972. Five have found their way to may shop (4 sold latter) and thirteen for friends and relatives at a charge. I’ve experimented with various designs and finally figured the best base design IMO, which I call my “whale-back” because of the center mounted stretcher that supports center table length-wise between end stretchers and legs.
But… this morning while standing over my table with a hand plane as flattening time has arrived, a thought occurred. What if I made the maple tops in 2-3 sections that the sections “are” glued together, and then butt joint those sections width-wise “without glue”? An end cap ties them on each end with counter-sunk lag screws securing the 2-3 sections to the end cap.
The sections are glued no wider than divisions of 12″. 36″ top = 3 sections of 12″ .. 30″ top = 3 sections of 10″.. 24″ top = 2 sections of 12″.. etc., etc. When flattening time arrives, you remove the lag screws and the top comes off easily. A quick couple of passes of the 12″ or less sections through my 13″ portable planer and I replace the top. Any ridge line at that point, I take off with a few passes with a card scraper. Done deal!
I have hand-planed them for years and it doesn’t take that long.. but I have encountered many that don’t have hand-planes, don’t want hand planes or just have no enthusiasm to get one and learn. Would this not be a viable solution to dragging out a belt sander and creating a “saw-dust storm” in the shop.
Just a thought.. anyone fore-see problems with sections butt jointed in the manner I described.. speak now or forever hold your peace.
Sarge. jt
Replies
Sarge,
Couldn't resist playing with this one, having just built one of the things. Thoughts on potential problems (assuming you are after working-out any possible drawbacks) are:
1) How do you keep the two or three pieces together, if they are not glued, at their inside (ie butted together) edges? The endcaps or breadboard ends will hold them in place but what happens when they expand/contract differentially to the breadboards? Something needs to give and slide but how? Will gaps open and close between the sections?
2) When the time comes to plane them through the machine, how do you keep the 2 or 3 sections aligned across their tops afterwards? Potentially, the position of the lag bolts holding the endcaps on to the boards might cause steps between the re-flattened sections, if those sections have not all been planed to exactly the same degree....?
I confess that I'm hoping my 2 foot wide maple bench top, made of 7or 8 laminated pieces, will only warp or wear very slightly, so only a light planing (or belt-sanding, with sanding frame and dust extractor) will be needed. As you have built a large number of benches, have you found that they go significantly out of flat, then, so that they need the degree of planing you seem to be suggesting?
Lataxe
Sorry to get back to you guys so late.. been in the shop working on that table-top all day.
Expansion was your 1st question..
(1) The majority of expansion is going to be from side to side, Lataxe. Keep in mind that the sections are made of of maple face that is face glued together. Maple will only slightly expand on the faces. Laterally is where the majority of expansion is and by face gluing, lateral becomes vertical.
Even if there was a small amount of extension between the 3 sections and a crack did open.. so what! We're talking a 1/8" or 3 mm . Maybe a tad more at most. That is not significant enough that a chisel or hand plane will fall through.. ha... ha....
Aligned afterwards.. causing steps between sections if not planed to same degree..
(2) I have a 44" table-top on my work bench at the moment. It was glued into four 11" sections then each section was flattened by a hand plane. Then the un-flattened side went through the thicknesser in sequence of thickest first determined with a wood micrometer. Once the first was dropped to the thickness of the next thickness, the thicknesser was lowered slightly till both were the same. Then the 3rd section in sequence, then the fourth till all were exactly the same thickness. That's how I do table-tops. When I glue the sections together, the most I get is a slight ridge-line that can be easily drawn down to level with a card scraper. So.. that's how I would do it.
I wouldn't be too concerned about your laminated work-bench. The one I currently use was an experiment in lamination to see what would happen. I was built 4 years ago with recovered Doug fir from beams laminated after being ripped and the top was a maple surround with laminated inner. This is only the second time I have had to true it in 4 years. Most solid tops I have built have to be trued sooner.
BTW.. I built a bench for my BIL about 5 years ago for free. He's a machinist shop foreman at Delta AL's and has done me some big favors. I used maple scrap and shorts laying around on the top ranging between 8" and about 18". I was granted use of a commercial finger jointer by a friend at his commercial shop. The entire top is finger jointed together with small pieces which most will tell you is a no-no.
At last check the top was off about a 1/16" and it has never been trued. So... tried and true traditional method are time tested, but if you use a little imagination you sometimes discover there is more than one way to skin a cat. :>)
Regards...
Sarge.. jt
Good idea. When I assembled my bench, I really didn't have many larger clamps at the time so I ran all-thread through the boards and just used that as a clamp. I suppose it could have been glued up in sections and the all thread would hold the sections together, and the end caps would help to keep it flat. --dave
Good thinking Old-tool. My first bench in 1972 was 2 x 4's on end with holes drilled through them. Ran a metal threaded rod through the holes and bolted it down. Gave it away in 1978 when I left Anheiser Busch and moved back to Atlanta.
You work with what you got and make it work, and it usually will if you give it enough thought.
Regards...
Sarge. jt
"The Workbench Book" and/or the "The Workbench" show several benches with multi-section tops for various reasons. Also the top of the Veritas benches are made of two 10 3/4" wide slabs with a tool tray down the middle. http://www.leevalley.com/wood/page.aspx?c=2&p=31152&cat=1,41637
Why the end caps and not a several cross ties under the top tieing the slabs together? Use quartersawn wood for the cross ties to minimize warping, and make sure they are finished with a reasonably water vapor resistant finish to minimize warping. Secure the slaps to the cross ties with lag bolts in round holes through the cross ties near the center, and through oval holes outboard to allow for differential movement of the slabs and the stretchers.
The cross ties will work for most David. I cannot use them on my benches as I in-corporate a "whale-back" running from end to end down the center of my bench. With that hefty back-bone I find the bench won't rack even if you don't glue the large mortise and tenons I use. Every section assist another section in strength from all directions.
If you need clarification, I will crawl under that puppy tomorrow after I get back from my CPA (taxes) and take a picture of what I refer to as a "whale-back".
Regards..
Sarge.. jt
If the purpose of your "whaleback" is to keep the bench from twisting then it doesn't need to be in contact with the top for the full length, just tied in very well at either end. You could put the whaleback down the middle, crossbars on top if it (possibly using a variation of a half-lap joint) and the two slaps on top of the crossbars.
I'm interested in a photo or two of your bench, both out of technical curiosity and also because I'm about to build a bench.
Hope these clarify, David. I have a 44" x 44" table top on-board the I wouldn't risk moving at this stage (denting) by myself, so part of the table is obstructed from view. Not sure how the underneath shots worked with the lighting, but hopefully you can at least get a picture of the spine.
It's lapped jointed into the cross stretchers. The top cross stretchers are saddle jointed into the to of the legs then pinned. Legs into base are through mortise and tenon and the bottom stretchers are all mortise and tenon. The shelf on bottom sits on a rabbet in the long bottom stretchers and pinned and glued to that stretcher.
Any questions.. shout!
Regards...
Sarge.. jt
Thanks for the photos. Make the "whaleback" a little deeper and lap the crossbars into it. The key joints are the whaleback to the end crossmembers.
I picked up the maple butcher block slab yesterday which will be the top of my new workbench. I'm looking forward to having a "real" workbench again. Currently it's sitting on sawhorses. Today I made some shelves for my wife and used the top for a workbench by clamping to it. It convinced me that a couple of vises and some dog holes are needed.
Hi Sarge,
They've got to be flat across the bench without going overboard.
If you go at them with a belt sander, then you'd have problems as you may end up with a faceted benchtop that has two or three different levels and angles of the various boards with respect to each other.
Now, if you used a thicknesser, registering off the bottom face each time, this would work ...
You'd probably also need to tongue and groove the boards or dowel them with 1/2" dowel at 4" spacing or so to avoid the thing from moving, as well as use a length of threaded rod or two to keep them together laterally.
Just a few really quick thoughts, and I see on re-reading your post that the thicknesser's already copped a guernsey.
It's a goer - just pin the boards together and stop them from moving laterally.
Cheers,
eddie
How's it going Eddie. Long time no hear, as I was AWOL awhile. The thicknesser comes into play in this scheme as most have a thicknesser but not all have hand planes or know how to use them.
And I hate.. and I mean "hate" the sawdust that gets airborne from a belt sander. If I use one at all.. it's outside period. ha.. ha...
Cheers mate..
BTW.. hope to make it back to down-under in about 2 1/2 years when I fully retire. Been a long time since I saw her last.
Regards...
Sarge.. jt
Hi Sarge,All well at this end of the world, we'll catch up if you do make it down here.Read through your other responses 15 minutes ago - I was putting a post on one of the less salubrious themes happening in knots at the time.Re: the workbench top, providing that each board's held flat against a cross rail (buttons or similar going into a groove in the cross rail, perhaps,) it would work fine with small expansion gaps.Just watch a top that wobbles with humidity changes.Cheers,eddie
Hey Eddie...
And I agree. With that, I'm off to bed as late on East Coast and I get to get up and do the same old things again tomorrow. Vacation (holiday down your way) my hinny. My lovely sends me to the shop to build for her in-satiable appetite for wood projects that end up in her possession and possession is 9/10ths of the law. ha..
I'm off to dream world.. at last.
Regards...
Sarge.. jt
grasshopper,
Makin us part of your big plan are we?
Lets see....can I just run my 12" wide workbench top through the planer to reflatten?
Hmmm...sure, as long as the underside is flat and parallel. Oh, wait a minute, a sled wouldn't do so maybe you'd better buy a 12 jointer for the underside...
"Honey, I asked the experts...."
Hope it works, BG
Why don't use just nail a piece of MDF to the current top and you will be within .004 of being flat without no any further ado, you dog you.. hee..
But.. you did hit on a major draw-back. In order to put sections through the thicknesser, you would have to joint one side (double pass with 6" or 8" and over-head guard attached for safety) on the bottom to get flat before the top side could see the thicknesser.
Another vote for anyone that doesn't have or doesn't intend to have a hand plane to get a jointer and planer or you can borrow my belt sander which hasn't seen use in many years.
Go cook some pancakes in anticipation of the next blizzard, BG. You didn't think the ole man had that kind of memory, huh... ha.. ha...
Regards..
Sarge.. jt
Sarge,
Yes, you do have an amazing memory ..even more so if you knew just how un-memorable my pancakes are. It must be in my DNA, yesterday we had our first snow fall, one inch, and I made pancakes.So the question is...if your going to joint one side before you can put it through the planer..why not just stop with the jointing and be done?Also, in my web travels, I remember a 'Jointers Bench' that had two separate slabs on top with a tool tray in the middle. That would work well with your whaleback design.
MDF may have a thickness tolerance of .004, but that doesn't mean it will be flat within .004 if it's supported on a warped surface. Also, MDF will warp if it has a higher moisture content on one side than the other due to differential contraction/expansion. How can that happen? Lay it on top of workbench and have the humidity change. The top side exposed to the air will change moisture content a lot quicker than the side against the workbench. Coating the MDF with a water vapor resistant coating will help considerably in reducing moisture differences within the MDF.
On the MDF front.. I was just razzing BG and not meant to be taken serious. BG and I go back a while and pokin' fun is just part of our normal exchanges.
And yes.. you are correct that cross supports could be lap jointed with the extra support "whale-back". Thought about that after I posted last night when I was brain dead from 14 hours in the shop yesterday.
PS.. have you a few pics in a about 20 minutes as just got back from my CPA.. it's tax time and that is something to be serious about. :>)
Regards...
Sarge.. jt
Just a thought...half kidding, but if one doesn't have or want hand planes...what does one need a real bench for?
Hey ThreePutt..
Just for fun I suppose. Same as one that wants a new and improved golf driver for extra distance when they 3 putt ever green. :>)
BG claims that I installed a pole of top of my bench for pole dancing and I operate a lounge out of my shop. There's another use and I could throw in picnic table when it's pouring rain outside. I also use it with an air mattress on top when the lovely points to the shop for whatever it was I did.
And the list goes on.. and on.... and on..... ha.. ha....
Regards...
Sarge.. jt
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