Joe Fabbri
03-14-2012, 1:22 PM
Hi everyone,
I have a bunch of wood sitting around for a future Roubo bench, but in the meantime, I'm thinking about building a Nicholson bench. It's been difficult handmilling this lumber without a bench with stops, etc, and I'd like to get to some other projects while the wood for the Roubo seasons.
I think the Nicholson design makes a lot of sense, and seems fairly simple to construct. For those who have built this bench out of construction lumber (I assume 2x12s for the aprons), how sturdy do you find it? I'm thinking about two 2x12s for the top, which would bring me to about 21.5" wide. I think that's a decent width. I suppose I could use three 2x10s and bring it into the 25-26" range, but I'm not sure if that would be necessary for a bench that I see most being used to plane boards/moldings.
One of my main concerns, though, is the use of holdfasts in standard 1.5" thick doug fir. Would the softer doug fir allow a holdfast to work okay in this thin of a top/apron? For the top, actually I'm not that concerned, as I was planning on notching the transverse bearers and adding a strongback down the center (maybe a 2x6), under the seam of the top. (Or two 2x4 strongbacks in the middle of each 2x12.) This would give a good holdfast surface, a good glue surface for the top, and stiffen the whole assembly.
For the side apron holdfasts, though, I'm not quite sure what to do. Some add blocking behind the holes, but I don't care for that idea too much. Some add a ledger for the bearers, which I like, but it won't back up the entire apron, and also it won't keep the bearers from potential twisting. So,I was considering laminating two 2x12s together. I know this is a lot of surface to glue together, but I think it's doable. I would keep the growth rings in the same direction probably, to make sure that the boards cup together, rather than break the glue joint if they work against each other (I think that would be better here).
By laminating it together, it would also make creating the stopped dados for the transverse bearers fairly easy; I could cut them out prior to the lamination. I'd also probably drill the holdfast holes first to aid in clamping up and alignment, by using some threaded rod or bolts and cauls. I could potentially screw both boards together in the location of the holdfast also, and drill out the holes created by the screws (as I'd rather not leave screws in it in the final product). Either way, I could find ways to handle the glue up, without a million clamps (which I don't have).
I wonder, though if it's overkill. I don't mind the extra mass (and maybe this bench design needs it, I don't know); but perhaps 1.5" is thick enough to work okay for the holdfasts. I see a bunch of Nicholson benches made with construction lumber, but there seems to be always some indication of problems with the holdfasts, either extra blocking added afterwards or hindsight saying 8/4 material would have been better to use.
So, any advice is appreciated.
Joe
I have a bunch of wood sitting around for a future Roubo bench, but in the meantime, I'm thinking about building a Nicholson bench. It's been difficult handmilling this lumber without a bench with stops, etc, and I'd like to get to some other projects while the wood for the Roubo seasons.
I think the Nicholson design makes a lot of sense, and seems fairly simple to construct. For those who have built this bench out of construction lumber (I assume 2x12s for the aprons), how sturdy do you find it? I'm thinking about two 2x12s for the top, which would bring me to about 21.5" wide. I think that's a decent width. I suppose I could use three 2x10s and bring it into the 25-26" range, but I'm not sure if that would be necessary for a bench that I see most being used to plane boards/moldings.
One of my main concerns, though, is the use of holdfasts in standard 1.5" thick doug fir. Would the softer doug fir allow a holdfast to work okay in this thin of a top/apron? For the top, actually I'm not that concerned, as I was planning on notching the transverse bearers and adding a strongback down the center (maybe a 2x6), under the seam of the top. (Or two 2x4 strongbacks in the middle of each 2x12.) This would give a good holdfast surface, a good glue surface for the top, and stiffen the whole assembly.
For the side apron holdfasts, though, I'm not quite sure what to do. Some add blocking behind the holes, but I don't care for that idea too much. Some add a ledger for the bearers, which I like, but it won't back up the entire apron, and also it won't keep the bearers from potential twisting. So,I was considering laminating two 2x12s together. I know this is a lot of surface to glue together, but I think it's doable. I would keep the growth rings in the same direction probably, to make sure that the boards cup together, rather than break the glue joint if they work against each other (I think that would be better here).
By laminating it together, it would also make creating the stopped dados for the transverse bearers fairly easy; I could cut them out prior to the lamination. I'd also probably drill the holdfast holes first to aid in clamping up and alignment, by using some threaded rod or bolts and cauls. I could potentially screw both boards together in the location of the holdfast also, and drill out the holes created by the screws (as I'd rather not leave screws in it in the final product). Either way, I could find ways to handle the glue up, without a million clamps (which I don't have).
I wonder, though if it's overkill. I don't mind the extra mass (and maybe this bench design needs it, I don't know); but perhaps 1.5" is thick enough to work okay for the holdfasts. I see a bunch of Nicholson benches made with construction lumber, but there seems to be always some indication of problems with the holdfasts, either extra blocking added afterwards or hindsight saying 8/4 material would have been better to use.
So, any advice is appreciated.
Joe