laminating a another top to my benchtop to increase thickness

[Mike williams54]

So I'm in the process of building my roubo, of sorts, and I'm coming to the realization that a 2.75" top is gonna be too thin. So I have a bunch of alder 2.5"x2"x8' boards that will be laminated. I was thinking of doing it in maybe 3 8" sections, then laminating maybe an 8"X1"x8' board of hard maple to add another inch of thickness. Does anyone think I will have problems with movement with this many joints and directions? I've already got most of the alder ready to go. But by the time I get it all planed its only gonna be 2.5ish 2.75 if I'm lucky inches thick. image.jpg
If this is a dumb question please just humor me, this is literally my second hand tool project behind a small dovetail box.

[Chris Hachet]

Not really sure of why two inches thick will be to thin. It won't look as good as a thicker top, but it should handle a holdfast just fine, and be steady enough for any kind of work.

[Chris Hachet]

...and from the pics it looks fine as is.

[Jim Koepke]

I'm coming to the realization that a 2.75" top is gonna be too thin.

That seems a decent thickness as is. My current bench is light and works fine with a top that is likely only about 1-1/4" thick top. It will work with a holdfast.

When the top gets much past 3-4" a holdfast can have problems.

jtk

[Richard Line]

I think the correct answer is - It depends. That's kind of waffling isn't it. If the legs are going to be quite close to the ends, then you'll end up with something like a 7' span between the legs. That length of span might allow the center of the span to sag or deflect too much when there is a heavy load, such as putting your 80 lb anvil there or chopping mortises in the center (down pressure from planning?). If the legs are moved in about 1 ft. from each end, then it will be about a 6 ft or less span - much better. I have a small bench with a doug fir top of about 2-3/8" thickness and approximately a 4-1/2 ft. span; it is quite stiff for planning and most work, although trying to chop in the middle is a bit springier than I like.

As Chris said, hold fasts will work in a 2" top.

If you want to add thickness using the maple board, I would probably place that board on the bottom and use mechanical fasteners (screws) near the edges of the board spaced 3 to 4 inches apart, unless it is quarter sawn. The board needs to be well attached to the upper top to reliably increase the beam strength of the top. If the maple is flat sawn, then I would be somewhat concerned with it trying to cup and possibly break a glue only joint.

These are my thoughts from my engineering background, not because I have a lot of knowledge or experience with making benches or wood structures.

[Jim Koepke]

although trying to chop in the middle is a bit springier than I like.

That is a good reason to chop mortises and dovetails over a leg.

jtk

[Mike williams54]

I plan to use a sliding tail vise, with a shoulder, mainly because they look really cool, joking, but they do look nice. And for that to work the top, or at the very least the shoulder itself needs to be atleast 4" if not 4.5" thick to house the mechanism, at least from what I undetstand from the very poor directions from woodcraft site. Linked here. http://www2.woodcraft.com/PDF/77A41.pdf
this is the vise I have. It's about 4" tall.
http://www.leevalley.com/en/wood/pag...36&cat=1,41659
im worried about getting it all together and then not being able to make the vise work properly. i want this bench to be around forever, and built well, sohere's a new plan, 1-2" thick quarter sawn boards glued(well) to the alder top. Probably white oak as that's what macbeths usually has quartersawn, sometimes walnut, but I'm on a budget. Or, do I cut my losses, about $200 and start over, then someday make a second bench with the thin stuff. Which is rather not do, but will. Oh, the boards in the pic aren't glued together, just clamped. Here's another thought, make it a split top, and do the front half thicker.... Guess I have some pondering to do.

[Jim Koepke]

How about using a deeper piece just where the vise mechanism is mounted?

It could even run the length of the bench to add some stiffness. Kind of like a recessed apron.

jtk

[Stew Denton]

Hi Mike,

One potential problem I see is that if the maple and alder have different degrees of expansion and contraction as moisture changes from winter to summer, which is expected with woods of different specific gravity, then the bench top could tear itself apart as the winter to summer expansion and contraction occurs due to changes in humidity. Also, lumber has different amounts of contraction and expansion, due to moisture content, for flat sawn versus quarter sawn lumber. So, if you do put the two sections of lumber together, the expansion will have to be the same for the two types of lumber and the lumber will have to either all be quarter sawn or flat sawn.

According to Scott Landis, quoting Roubo in "The Workbench Book" a true Roubo was 5 to 6 inches thick made from a single plank, 20 to 24 inches wide, and 6 to 12 feet long, with a typical length of about 9 feet. The lumber was elm or beech, with the heart wood facing up. Landis adds that the French inch is a bit bigger than is our inch, so in fact the bench top thickness was actually a bit more than what is listed above.

Rob Tarule built a true Roubo, which is described in the workbench book, and his was only 4 1/2 inches thick, and he gets by just fine with that thickness.

A problem with this thickness, as Jim points out above, is that modern commercially available holdfasts do not work well in a top of this thickness, as they are too small. Tarule finally ended up having to have a blacksmith make some custom holdfasts, like those Roubo described, that were 1 1/16 inches thick in the shank, with octagon shaped cross sections, which were in the 15 to 20 inch length, as Roubo described. He also had to bore holes 1 1/4 inch in diameter to get them to work. They cost him $130 to have made, and that was about 30 years ago.

Since you asked, if it were me, I would start over if I wanted a true Roubo. However, if you just want a high quality bench that will last a very long time, and want to use your existing alder lumber, you might consider the Frank Klausz type bench. Thick on the vise side of the bench and 2 1/2 inches thick for most of the rest of the bench. It is a continental European design. Great bench, and completely compatible with the type of vices you describe. (For what it's worth, the original Roubo benches had no vises, but later on some did have leg vises.)

Regards,

Stew

[Mike williams54]

You're right stew, I have read both Scott landis and Chris Swartz workbench books and I guess I'm really taking bits and pieces from all the different benches. The flush to legs like the roubo, I really like the the one that schwarz built using the solid slab in the beginning of the book. But I'll never find a slab that large or the skill to mill it down or move it around. His slab was 5" thick. And that's what I'm going to go for. I think I can glue the alder I have together to achieve about that tall then just get some more. I'm only going to do it once after all. And even the klausz bench, described in landis' book has a 4" top.

[Stew Denton]

Mike, I have to admire your confidence, the double through mortise and tenon joints that attach the top to the legs is more than I would even attempt at my level of skill (or the lack thereof.)

My son in law has Schwarz book, and I have scanned through it, but currently have his copy of "The Anarchists Tool Chest" so would have felt guilty about borrowing both books at the same time. I will have to look at Schwarz version of the Roubo the next time we visit them. Your comment has gotten my interest way up, because I didn't even realize that there was a Roubo in that book, so I will have to read what he has written about it.

I too have been thinking about what I would like to build for a workbench, because I work primarily on planks on sawhorses, which have to be outside or put up every night so that the car can go back in the garage. I need to either clean out the junk in the garage so I can leave things set up in there or build a small shop....I'm hoping for a shop. I have thought about some hybrid bench too, but the more I've thought about it, and the more I have thought about what I like to do and what I would like to eventually be able to build has made me think a lot about building some hybrid copy of the Klausz bench. If I do build one, it will likely be SYP, the good stuff is too rich for my blood. I wouldn't even attempt a Roubo.

I have to say, though, while I do agree that the front rail of Klausz bench is 4 inches thick, I believe the main part of the bench is 2 1/2 thick. Klausz wrote an article in the July/August 1985 issue of Fine Woodworking, about his bench and building it. The grain pattern on the bench in the 1985 article and the one in the Landis book show that the bench in both is the same bench. In that article he says that the section of the bench that is the center part was made from 2 1/2 inch quarter sawn maple, which is sandwiched between the thick dog rail section and the back tray assembly.

You mention that this is going to only be your second hand tool project. Are you planning to do almost all of the work with hand tools?

Also, I am wondering what your thinking on the main advantages are for a Roubo for your work, is it mainly the substantial strength and potential very long lifetime of such a bench if you build it right and take care of it? On the other hand are their some other factors that make it fairly ideal for projects that you build?

I think about building a bench that can be handed down to one of my grandkids. That would seem to favor maple instead of SYP, but the nice lumber is so pricy it is difficult for me to justify.

Regards,

Stew

[Stew Denton]

Mike, if you do build a Roubo hybrid, like you are thinking about, please take pictures and write up a bit as you go. I would really like to follow your project, and see what you build, and I would guess there are others who would also like to follow it.

I don't have any idea how to put pictures in a post, but think my wife can show me how to do it. If I could add pictures, I would like to write a post about a plane I am restoring.

Stew

[Mike williams54]

I've been taking pics, and i would have preffered maple, but it's far too spendy for me especially being a learn as you go project, I have been using my table saw, but everything else has been hand tools, so far, I might break the jointer out soon though to prep the rest of the rough material for the table saw, but hand planes are so much more enjoyable, and I'm not on any timeline.l, I enjoy this a lot, and learning as i go. Alder was surprisingly cheap here in utah so that's what I chose. And stew, you're probably right. I just glanced through the book to look at the klausz and just looked at the diagram which only showed the front being 4". But really, I'm not following any real plans, and what I want to use the bench for is basically to be able to take whatever I can through at it til I die. And a thick solid heavy bench should handle anything i could possibly through at it.

[Stew Denton]

Mike,

I may have to look into Alder. In the recent Tony Wilkins post on building an Anarchists Tool Chest, I think he mentioned that alder is fairly inexpensive in Lubbock, which is not too far away from here.

I have never used it, and so know nothing about it, but if it is fairly stable and moderately dense it may be just what I want. Like you, I think maple is too expensive, especially at my level of skill. I can mess up SYP for quite a bit less money. I will have to look for information on it on the net.

Stew

[Curt Putnam]

As I remember things Alder is even softer than Poplar. I was dissuaded from using poplar for a bench top because of very fast hole wear when used with holdfasts. I wound up going with soft maple because I got a good (for here) price on it. In my mind, alder makes a very nice furniture wood (poor man's cherry) but not so much for bench tops. Will alder work? Of course it will, for a while and up to a point. For inexpensive, depending on where you are, either SYP or Doug Fir should be your choice. Next move up the scale is soft maple.

A split top out of two different wood thicknesses could work theoretically but I see it as a bear to level. Print out a copy of the Janka scale and get whatever wood that you can afford. If you don't care about the multiple lifetimes of use from the bench (apparently most 1st benches are dumped early in their life) then use the alder and do what you have to do to get thickness enough for your tail vise. Use it until you know what you really want and then build your multiple lifetime bench.

JMO & YMWV