Luke Dupont
04-15-2022, 12:23 AM
Hi guys. Some of you may be aware of my previous adventures and mishaps with gluing cross-grain battens on my current workbench, which causes the wood to cup due to the batten not expanding, but the top being able to, like so:
477598
However, many Historical designs use cross grain battens, in fact, and I'm wondering what the best fasteners would be for this (if one were to use fasteners rather than joinery, and in any case, certainly not glue!):
477599477600477601
The design above, from Bernard E. Jones' book, "The Practical Woodworker" (Volume I) is what I am considering making, as it is very similar to my current bench already. It would just mean remaking the top (which I already need to do anyway) and adopting folding legs, which I've always wanted to try ever since seeing The Woodwright's version of this very same bench. Roy Underhill, in his version, removes the vise and adds an Apron around the entire bench. Can't find a picture of Roy's, but here's one from closegrain.com that someone built just like it:
477602
I'm not sure which I like more: with or without the apron. But I know I like the tail vise on the original.
In either case, they both use cross-grain battens, and that presents some challenges. I actually bought Roy's book which features this bench to see if he goes into detail, but neither Roy nor Bernard talk specifically about how to deal with the expanding top. Roy just says to use screws to attach the batten, and if you look at the pictures in the book closely, you'll see he left some minor gaps between the stretchers and the skirt to allow for the wood to shrink. But that's it.
I am, of course, determined not to make the same mistake, so I'd like to take a little more precaution. I'm sure using screws and not glue (like I did on my current bench) allows for some expansion, but I am thinking that I may want to use slotted screws or nails.
The workbench top and tool-well together will come out to 18-20 inches wide in total, which, going by research from my previous thread, should expect to see as much as 3/8" of expansion / shrinkage in total.
So, I'm curious how other people would approach this. Would you:
1. Just screw it on?
2. Just Nail it on? I understand that nails move more with the wood than screws, and maybe they alone are sufficient in this case?
3. Use slotted screws on the ends of the battens, and attach the middle firmly with a few non-slotted screws (this would allow expansion to occur outwards and keep the fold out leg braces centered)
4. Use slotted screws in the middle, and fix the ends of the batten firmly in place. Cut a rabbet/half lap in the underside of the 2" bench top to allow the tool well board and bench top board to overlap. Expansion will occur towards the center rather than outwards from the ends, but this would mean that the leg braces move slightly sideways with the seasons... Probably not an issue?
5. Some combination of screws and nails, with nails allowing for movement, similar to #3 and #4
6. Something else?
My intuition is that #2 is just fine, #1 is probably okay but may see some minor cupping (not as much as I currently see with glued battens), #3 is best if I go with the no skirt design, and #4 is best if I go with the Roy Underhill version, which has a long-grain skirt going around the whole bench.
Also, I've never done a slotted screw. Do you just rock the drill bit left and right? Do you go from both the top and the bottom, or just the bottom? I don't have powertools to do this, so I need a handtool method that works. I did a test run and tried chiseling a 1/8" slot (this for another project), and then chiseling out a "countersink" bevel for the screw head, and.... it was really ugly and not convincingly strong looking or feeling.
I am tempted to just nail the whole thing on, but I'm not convinced that nails alone will hold the batten well enough, and I'm concerned that they will perhaps work lose and compress the fibers with time, allowing the bench to become "racky". Then again, they're supposed to be stronger in the lateral direction, and screws can potentially chew up the wood and do the same. Most likely I'm over thinking this, and either will work just fine for however long this bench stays in service.
477598
However, many Historical designs use cross grain battens, in fact, and I'm wondering what the best fasteners would be for this (if one were to use fasteners rather than joinery, and in any case, certainly not glue!):
477599477600477601
The design above, from Bernard E. Jones' book, "The Practical Woodworker" (Volume I) is what I am considering making, as it is very similar to my current bench already. It would just mean remaking the top (which I already need to do anyway) and adopting folding legs, which I've always wanted to try ever since seeing The Woodwright's version of this very same bench. Roy Underhill, in his version, removes the vise and adds an Apron around the entire bench. Can't find a picture of Roy's, but here's one from closegrain.com that someone built just like it:
477602
I'm not sure which I like more: with or without the apron. But I know I like the tail vise on the original.
In either case, they both use cross-grain battens, and that presents some challenges. I actually bought Roy's book which features this bench to see if he goes into detail, but neither Roy nor Bernard talk specifically about how to deal with the expanding top. Roy just says to use screws to attach the batten, and if you look at the pictures in the book closely, you'll see he left some minor gaps between the stretchers and the skirt to allow for the wood to shrink. But that's it.
I am, of course, determined not to make the same mistake, so I'd like to take a little more precaution. I'm sure using screws and not glue (like I did on my current bench) allows for some expansion, but I am thinking that I may want to use slotted screws or nails.
The workbench top and tool-well together will come out to 18-20 inches wide in total, which, going by research from my previous thread, should expect to see as much as 3/8" of expansion / shrinkage in total.
So, I'm curious how other people would approach this. Would you:
1. Just screw it on?
2. Just Nail it on? I understand that nails move more with the wood than screws, and maybe they alone are sufficient in this case?
3. Use slotted screws on the ends of the battens, and attach the middle firmly with a few non-slotted screws (this would allow expansion to occur outwards and keep the fold out leg braces centered)
4. Use slotted screws in the middle, and fix the ends of the batten firmly in place. Cut a rabbet/half lap in the underside of the 2" bench top to allow the tool well board and bench top board to overlap. Expansion will occur towards the center rather than outwards from the ends, but this would mean that the leg braces move slightly sideways with the seasons... Probably not an issue?
5. Some combination of screws and nails, with nails allowing for movement, similar to #3 and #4
6. Something else?
My intuition is that #2 is just fine, #1 is probably okay but may see some minor cupping (not as much as I currently see with glued battens), #3 is best if I go with the no skirt design, and #4 is best if I go with the Roy Underhill version, which has a long-grain skirt going around the whole bench.
Also, I've never done a slotted screw. Do you just rock the drill bit left and right? Do you go from both the top and the bottom, or just the bottom? I don't have powertools to do this, so I need a handtool method that works. I did a test run and tried chiseling a 1/8" slot (this for another project), and then chiseling out a "countersink" bevel for the screw head, and.... it was really ugly and not convincingly strong looking or feeling.
I am tempted to just nail the whole thing on, but I'm not convinced that nails alone will hold the batten well enough, and I'm concerned that they will perhaps work lose and compress the fibers with time, allowing the bench to become "racky". Then again, they're supposed to be stronger in the lateral direction, and screws can potentially chew up the wood and do the same. Most likely I'm over thinking this, and either will work just fine for however long this bench stays in service.