Workbench 2.0 Build

[Zuye Zheng]

Started woodworking almost 2 years ago without a clue (as seen by vise placement), an eye for power tools, and the nicest set of plastic handled chisels the big box stores could offer. My first project was this workbench with a plywood top, thinking I needed a huge power planer to make anything better. With a vise upgrade, has served pretty well though...
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However, ever since taking the deep dive into neander woodworking, been planning a more traditional workbench. With some time off, finally starting a split top Roubo with a Benchcrafted leg vise and Veritas quick release tail vise. Being a scrooge with wood, will be building the 3" thick 7' long top with mixed species. The front 14" half will be from 8/4 hard maple (puppy for scale).
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The back 8" will be from cheap scarf jointed (for length) reclaimed Philippine mahogany (used for stickering train tracks?) that has been drying for a while.
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I plan on laminating doug fir 2x4s to make 3.5x6" legs with mahogany stretchers. I'm thinking a 2" hard maple chop for the leg vise, but considering the recent thread on thickness of the chop and Schwarz also recommending 3", might laminate up a 3" chop instead. However, worried about the usable depth of the vise, since it is only around 9ish" to start (compared to the 14" of my metal QR). Also, for the the leg with the vise, plan on using more of the mahogany instead of the doug fir. Any glaring problems with the plan?

[Pat Barry]

That's a very nice bench dog!

[Stew Hagerty]

That's a very nice bench dog!

Dang... You beat me. I was going to say that.

Zuye, looks like you're off to the races. Keep us updated. We love pictures!

[Christopher Charles]

Dog gone it! Beat me to it too. One question: is that a square or round bench dog?

[Richard Line]

My guess is that bench dog wags both ways.

[David Eisenhauer]

As you have seen, it was a mistake to include the photo of the "shop dog" with a serious question. What kind of dog are we looking at here? I can't answer any Doug Fir questions, as I am a SYP kind of guy when it comes to less-expensive wood for benches. Vise opening width? Takes a lot to start deflecting 2" material, never mind 3". What dimension timber will you typically be working with? Normally speaking, I tend to believe in planning for the typical main event use as opposed to setting up for the once-in-a-lifetime (or some variation thereof) event.

[Stew Denton]

Hi Zuye,

I don't see any difficulties with your choice of wood, with one possible concern. The concern I have is your glue up of the hard maple to the mahogany. I have some Philippian mahogany that is pretty dense, and have also used some that was pretty light with low density. This leads to my concern with the glue junction of the mahogany to the maple.

There may be a significant difference in the expansion/contraction of the mahogany versus hard maple as the humidity in the wood changes with the seasons. This may want to tear that joint apart. On the other hand, it may not be enough of a problem with the 3" thickness to be concerned about.

The wood data base list the shrinkage of the various species of P.M. as having radial shrinkage from 3.3 to5.5%, and tangential shrinkage running from 6.9% to 10.1%, depending on the species. For hard maple it lists these as 4.8% radially and 9.9% tangentially. The biggest differences between these two, would be 9.9 to 6.9, for a difference of 3% if both pieces are jointed tangentially. The worst case would be to joint one piece of the PM that was cut radially to the hard maple cut tangentially, and this would be a difference of 6.3%

These two differences account for a worst case difference in the change of thickness of from 0.09" to about 0.20" for the two worst case glue ups. What this means in practical ways is that if you glue up the two dissimilar woods tangentially when they were at the dry end of the spectrum, and then had a long damp summer where the wood swelled to its maximum normal thickness, you would have a total difference of thickness of the lumber at the joint of from about 1/10 of and inch to about 2/10ths of an inch.

This might tear apart the glue joint, or at the least cause a difference in thickness of the top at the glue joint of the two types of lumber as the season, and hence moisture content and thickness of the wood, changed. This difference in thickness would be assumed to be equally divided between the top and bottom halves of the top, but worst case this would still be about a tenth of an inch.

If I were building the bench, I would try to orient the grain the same way if I was going to go with the two different wood, and thus, if both sections of the bench top were carefully selected so that all the lumber was cut tangentially, the worst case difference would be about 0.045 inches on each the top and bottom of the bench top. This is a bit less than 1/16th inch. With a lucky selection of the types of lumber, it might be less than 1/2 this amount.

It really comes down to how much risk on the thickness of this joint are you willing to risk. How much of a step change in bench thickness at that joint can you live with. If it is a lot less than the figures listed, you might think seriously think about going with one species of wood for the entire top.

To my way of thinking, this is one reason to go with only one species of wood, or pick two species that have the same change in thickness with change in moisture level. It is also a good reason to choose the lumber carefully so that you orient the growth rings similarly in each piece.

With regard to the exact lumber choice, I would love to have a bench with a hard maple top. However, for me I will probably have to settle for either Old Yeller pine or Dog Fur.

Stew

[Zuye Zheng]

As you have seen, it was a mistake to include the photo of the "shop dog" with a serious question. What kind of dog are we looking at here? I can't answer any Doug Fir questions, as I am a SYP kind of guy when it comes to less-expensive wood for benches. Vise opening width? Takes a lot to start deflecting 2" material, never mind 3". What dimension timber will you typically be working with? Normally speaking, I tend to believe in planning for the typical main event use as opposed to setting up for the once-in-a-lifetime (or some variation thereof) event.

Ya, she seems more popular than the build. She was a 6 month old golden retriever in the photo, around 10 months now. Was concerned about vice opening width, the screw is around 14", 3.5" for a leg, 2" for a chop and you get to only 8.5" usable. Thinking about it, it is probably more than adequate especially considering all the new work holding options including hold fasts, etc. that didn't quite work with a plywood top.

I don't see any difficulties with your choice of wood, with one possible concern. The concern I have is your glue up of the hard maple to the mahogany. I have some Philippian mahogany that is pretty dense, and have also used some that was pretty light with low density. This leads to my concern with the glue junction of the mahogany to the maple.

Was worried about this as well, it will actually be a split top so the 2 species won't be glued together. As a side note, the variation in the Philippine mahogany was pretty interesting, from changes in density to one piece that dulled my plane blades faster than the hard maple.

[Zuye Zheng]

Have the 2 tops mostly laminated and flattened.

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There is still 4" to go on the maple top but it won't be full length to accommodate the tail vise. Been mostly hand tooling except for ripping the maple with a circular saw since it was too heavy to pass through the table saw, quite the work out planing everything...
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[Christopher Charles]

Looking good. The split top is a good choice given the mixed wood.

Also, FYI I measured the thickness on my chop at 2.5"

[Stew Denton]

Hi Zuye,

The top sections really look great, nicely coming together.

Stew

[peter Joseph]

just my opinion but if I built my roubo again, I'd go with a 3" chop (Still can replace it of course and probably will in due time). My 2" QSWO chop flexes on occasion. Not often, but enough to make me wish I had a 3" chop.

[Stewie Simpson]

Peter Joseph; would you do us the honour of reposting photo's of your completed oilstone box, and H.O. Studley replica cabinet .

regards Stewie;

[David Wong]

Zuye,

Your scarf joint look impressively tight. My small experience is that they are not as easy to cut as they look.

[Zuye Zheng]

Zuye,

Your scarf joint look impressively tight. My small experience is that they are not as easy to cut as they look.

Thanks! I undercut one of the angles to get a tighter fit at top.

Made some more progress, have the top mostly laminated, came out to 23.5" with a 2" gap.
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Have the back section breadboarded.
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Also have most of the other pieces milled including a 6x4" mahogany piece for the leg vise and slightly smaller ones of douglas fir.
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