Roubo Is Coming… Part 28

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The planing stop bites into the workpiece and holds it in place effectively

While the focus of this build has been on trying to hew as close to Roubo’s description of the French-style bench as far as possible, when planing my “Roubo” bench I decided I wanted to add a swing away seat by Benchcrafted. I find chopping dovetails, and some detail work, more comfortable when sitting at the bench instead of being hunched over it, and having a seat which is attached to the bench and folds out of the way, seems to be a space-efficient solution. I fitted the swing away hardware to the right-hand bench leg over the Christmas break, but hadn’t had an opportunity to turn the seat itself until this weekend.

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Planing the seat blank smooth

I had been saving an offcut of the oak slab I used for my Mortise & Tenon stick chair for the seat top, which meant I could keep to a single species for the whole bench. I cut the blank into a rough hexagon, about 12″ wide, and then planed it to 1″ thick. This also gave me a chance to test out the planing stop I fitted last week, and found that it gripped the workpiece very well indeed with only a sharp tab with a mallet to drive the workpiece onto the teeth of the stop.

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Marking out the diameter of the seat, on the underside

Once the seat was at final thickness I scribed an 11″ diameter circle on the rear side, and then removed some more of the excess material forming corners with a back saw, in order to reduce the risk of a catch on the lathe. I then mounted the lathe faceplate onto the rear of the seat, and slid the seat into position on the lathe.

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Turning the seat blank

This is the first time I’ve turned anything this year, and while a 11″ wide disc is about as simple as turning can be, it was immensely satisfying. The process of taking an irregular-shaped piece of wood and changing it to a perfectly round circle in a short period of time was remarkable, and I”m looking forward to turning some bowls and platters later over the coming months. To turn the seat I used an EasyWood roughing tool for most of the grunt work, followed by an EasyWood finisher to clean up the surface and to round over the corners a little. After drilling the holes for the mounting screws and mounting the seat on the hardware bracket, I applied a coat of boiled linseed oil to the seat top.

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Fitted and ready for oil

This was a quite a simple stage in the build, but it was very satisfying to get another element of the bench finished in what has proved to be a very busy week. All that remains now is to make the grease box, and then to mount the shelves on the stretchers. Roubo is very nearly here.

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The oiled seat, ready for use

Roubo Is Coming… Part 27

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Marking the final width of the tenon

I find it interesting how a lot of work can result in something very simple. And how simple does not always mean straight forward (or easy). At first blush, the planing stop is incredibly simple – a square mortise and a square loose tenon that fits the mortise. But that simplicity requires a lot of attention, and being prepared to fuss over the fit. The planing stop needs to be friction fit to the mortise – too loose and it will fall out of the mortise. Too tight and it won’t move at all, or worst case, will split the bench top. So, this most simple element takes time and patience. But that’s ok – I work wood because I like spending time at the bench. One day (soon, hopefully) the bench will be complete, and I’ll be using it to work other projects. All of that is a slightly round about way of saying that the planing stop is fitted and functioning as intended.

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Using the No3 smoother to fine tune the fit of the tenon

Before I started fitting the stop itself I checked the mortise, and did a little tuning with a 1″ paring chisel to remove any bumps or stray lumps. With the mortise in good shape, I started to fit the tenon. I had deliberately left the tenon a few mm oversize, pending the final fitting, and so the first task was to take it down to size. At this point, the numbers are not important, what matters is that the stop fits the mortise well enough to move freely when encouraged with a mallet, but tight enough not to move otherwise. I presented the tenon to the mortise and got two perpendicular sides pressed nicely against the mortise walls. I had deliberately struck the layout lines for the mortise longer than necessary, as this helps to fit the stop. With the tenon located firmly against two sides, I marked off the final width on the remaining sides by dropping my marking knife into the mortise layout lines and nicking the side of the workpiece. I used these marks to set a marking gauge, and struck lines on the stop to identify the final width.

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Chamfering the corners

After planing the stop down to the marking gauge lines, I tested the fit in the mortise, and made fine adjustments with a smoothing plane until the stop moved 1/8″ with each mallet tap (thanks to Mark Hicks for his advise on fitting the stop and this tolerance as being a good indicator of appropriate friction). This took several rounds of fitting, and making small localised adjustments with the plane. I also knocked down the corners with the Phillychamfer plane, as these are a weak point and I did not want any stray fibres in the corners spoiting the fit. I had not squared up the top end of the tenon, and once it was fitting in the bench I planed it flush with a low angle block plane.

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Planing the show-end flush and clean

After testing the movement of the stop through its full length, it was time to drill the hole for the toothed planing stop itself, which Peter Ross forged for me a few years ago. The planing stop had a tapered shaft with a square cross-section, and I drilled the holes while the tenon was fitted in the bench top. I bored the narrowest diameter hole needed first, which was the full length of the stop, using an auger in my North Bros brace. After this, I used engineering bits in an egg beater drill to drill the remaining, wider sections. The tip of the engineering bit follows the path of the pilot hole better than a spur and centre wood bit, which makes them very useful for reaming wider holes. Once the pilot holes were drilled, I hammered the stop into position, placing a saw bench underneath the wooden part of the stop to prevent it being driven through the mortise.

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The toothed planing stop fitted in a 15″ long tenon

To prevent the teeth of the stop from sitting on top of the bench (and catching tools or fingers) when not in use, I knocked the stop as close to the benchtop as possible, and traced roung the teeth with a marking knife. After removing the stop from the mortise, I used a chisel to deepen my marking knife lines and a small router plane to remove sufficient material to allow the teeth to rest under the surface of the bench. This is a small detail, but one which did not take too long and which adds a nice point of interest (and functionality) to the bench.

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Fitted and ready for use

Roubo Is Coming… Part 26

While I was in a boring frame of mind after last week’s blog post, I bored out the waste for the planing stop mortise, using the same WoodOwl ship’s auger in my North Bros brace as I had for the holdfast holes. With 8 holes bored round the perimeter of the mortise, the middle portion of waste lifted out easily. The second feature of the holdfast drilling jig then came into play – the 90 degree face providing a useful surface to register the 1 1/2″ timber framing chisel on when paring the mortise flush without any undercutting.

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Paring the mortise flush with a timber framing chisel

The planing stop needs to be friction fit in the mortise, so that it can be easily adjusted with a mallet, and not so tight that is splits the bench top. Having a consistently sized mortise will make fitting the planing stop a lot easier, and also a lot less prone to seizing up (I hope). So some effort getting a clean mortise is definitely time well spent. I started by paring the to end grain surfaces perpendicular to the top of the bench, followed by the long grain sides. This sequence of work ensured that chopping the waste from the long grain would not result in a split in the bench top. I cut the mortise entirely from the top, as flipping a completely assembled Roubo bench sounded a lot like work. There was some minor blowout on the underside, but nothing any one will see, and certainly nothing that will impact on the integrity of the slab.

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A square and true mortise

Once the mortise walls were pared clean I did a final sweep round the corners, which is invariably where junk collects. I did allow some slight undercutting in the corners, as the substantial sides and ends of the mortise will provide the gripping power on the planing stop, and relieving the corners ensures a good fit without reducing the necessary friction.

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Squaring the planing stop

With a clean and plumb mortise, I started work on the planing stop itself. This was the first opportunity I’ve had to use the Benchcrafted Glide C vise since I installed it in the bench, and I was not disappointed – it combines sweet and smooth movement with a tenacious grip. Processing the planing stop in the vise with the big Lie-Nielsen No8 was a rock solid experience, and I’m looking forward to spending the rest of my life working with this vise hardware. Processing the planing stop was pretty usual fare – I trued up two perpendicular faces, testing for a 90 degree angle with the Vesper 4″ square, and then worked the remaining two faces from the reference surfaces. I left the planing stop a hair oversize at this stage so that I can bring it down to final dimension while I am doing the final fitting.

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It’s not square until Chris Vesper tells you it is square

Roubo Is Coming… Part 25

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WoodOwl ship’s auger and 1920’s (pre-Stanley takeover) North Bros brace

After a few days of building up the courage to start boring holes in my newly flattened bench top, the holdfast holes are all now bored. Truth be told, it wasn’t that terrifying a proces after the first hole, even if perforating a newly flattened bench top does feel counter-intuitive.

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Scribing the hole diameter helps to line up the drilling jig)

I don’t tend to make many jigs, partly because I don’t find jig-building all that satisfying (I’d rather be building furniture or musical instruments). But when it came to boring the holdfast holes in the bench top I did decide to make a simple jig which would also be useful for cutting the planing stop mortise. This jig is essentially a 2 1/2″ high piece of hardwood glued to a 3/4″ thick plywood base. The face of the jig is at 90 degrees to the base, so that it can be used as a guide block for a timber framing chisel when paring the mortise walls. A 1″ diameter hole was bored through the jig to provide a perfectly plumb guide for boring the holdfast holes – this is critical if the holdfasts are to function properly. The plywood base is deeper and longer than the hardwood, which allows it to be clamped in position. The whole thing took probably 30 minutes to make, and won’t win any beauty prizes, but it has proved to be very useful.

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Boring a holefast hole with the drilling jig – dirt simple and effective

I started boring the holdfast holes with the rear-most row first, working from the front end of the bench to the back, and then in the opposite direction for the second row. The holes were bored with a 18″ long, 1″ diameter ship’s auger by WoodOwl, driven by my 1920s North. Bros brace. The additional length of the ship’s auger makes it easier to see when the bit is plumb, and also facilitates the use of my simple drilling jig, where the standard bits are too short.

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Before clamping the jig in place, I scribed a 1″ diameter circle around the location of each holdfast hole with a pair of dividers – this made it easy to see when the jig was lined up properly on the centre point. The jig was clamped in place and I started boring out the hole. Once the auger bit screw had engaged with the bench top I checked alignment with a 10″ square as a safety check, and made any minor adjustments to keep the hole plumb to the surface.

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The process is very simple, but even with the fast cutting WoodOwl bits, boring 5 3/4″ thick oak felt a little bit like work and 10 holes took a while. The WoodOwl bit cuts very nicely however, and left wonderfully clean holes which look very neat on the benchtop. The length of the plywood base for the jig worked nicely, as I was able to span the jig across the width of the bench, and also on the diagonal where necessary to avoid the bench legs.

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Testing the Crucible holdfasts

Once the holdfast holes were bored, I did a test fit to check that the holdfasts fitted and gripped properly. The Crucible holdfasts grip like the absolute dickens with only a sharp tap from a lump hammer, so the workholding on this bench will be spot on.

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The completed holdfast layout

With the holdfast holes bored, I was able to check the location of the planing stop mortise, and decided to scoot it back 2″ closer to the front end of the bench, so that there is room to fit a long batten across the width of the bench with one end secured by the planing stop and the other by a holdfast – this will help when planing long panels. The next job is to bore out and chop the planing stop mortise, and fit the planing stop.

Roubo Is Coming… Part 24

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Setting the dimensions of the planing stop with the Pied du Roi ruler

Having spent a great deal of time and effort getting the bench top flat and looking good, the prospect of drilling a bunch of holes, and cutting a large mortise in it, feels very counter intuitive. The holdfast holes and planing stop are at the cornerstone of my workholding strategy for this bench, and consequently they are critical. But even recognising that, preparing to drill through the newly finished bench top is a little daunting.

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A birdcage awl leaves a clear location mark for each holdfast hole

The bench top will have ten holdfast holes – a row of six spaced 3.5 pouce from the rear edge and on 16 pouce centres, and a second row of four holes which are 10 pouce from the rear edge of the top and situated also on 16 pouce centres but offset by 8 pouce compared to the rear row. This is essentially as Chris explained on his Popular Woodworking blog a few years ago. The planing stop mortise measures 3 pouce square, and is located to the left of the front left leg, 3 pouce from the edge of the bench top.

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Laying out the second row of holdfast holes – one combination square sets the distance from the rear pf the slab, and the other sets the distance from the rear row of holes

While the oil was drying on the vise chop, I spent some time laying out the location of each holdfast hole and the planing stop mortise, using the Pied du Roi ruler Brendan made me. Setting all of my measurements from this ruler avoids having to do any mental conversion, and minimises the risk of any layout or measurement error. I started by laying out the back row of holdfast holes, marking the location of each hole with a birdcage awl. With the first row of holes marked out, I was able to then layout the second row by placing the holes equidistant between each hole on the first row, and and the correct distance from the back of the bench top.I found a pair of combination squares useful for this task, one set to the offset between the rear hole and the front row, and the other set to the distance from the back of the slab. The first combination square was then able to reference directly from the ruler of the second, giving an accurate and consistent way of positioning the holes each time.

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The planing stop mortise was also laid out with the Pied du Roi, this time my Hamilton Tool Works Traditional Marking Gauge stiking lines to define two sides of the mortise. The extra long beam Jeff suggested for this gauge definitely paid off when marking out the back line of the mortise. The remaining sides were marked with a Vesper 10″ square referencing off the side of the bench top.

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By this time the oil had dried on the vise chop, so I did the final fettling and fitting of the Benchcrafted vise hardware. Once fully installed, the hardware moved sweetly and very rapidly. Adding the vise chop also makes the bench look a lot more “completed”. I’ll pluck up some courage and then start boring out the holes in the bench top, which will complete the functionality of the bench. The end is very, very near.

 

Roubo Is Coming… Part 23

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An unhandled marking knife easily marks the final length of the vise chop

The vise chop is one of the few areas where you can add an individual touch to the design of a Roubo workbench, and a Google search can show a whole gamut of different chop styles. For the chop on my Roubo bench, I decided to go for a simple round over which fit the simple aesthetic of the bench while adding a curve to a very rectilinear project.

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Laying out the round over with French curves

Before shaping the chop I first needed to trim it to length. I had deliberately left the chop over-long as I did not know exactly what thickness the slab top would end up once flattened. To level the chop I mounted the hardware, and then used an unhandled Hock Tools marking knife to strike a line on the inner-face of the chop, flush to the benchtop. With the final length marked out, I then laid out a curve using the “Roubo” French curves from Sterling Tool Works (let’s be honest, I had to find an opportunity to deploy the Roubo curves on this project didn’t I). Once I had a curve that was pleasing to the eye I marked this on both sides of the chop, and also struck a line at 45 degrees from the top of the chop to the face which fell just outside the arc of the round over. I clamped the chop side-down to the bench top, and cut down the 45 degree line to remove most of the waste before trimming the excess length off the chop.

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MOst of the waste can be removed with the saw

I am now at the stage of the build when I can use the bench to build the remaining components of the bench. To shape the chop I re-mounted the hardware, and sat on a saw bench, which put the workpiece at a comfortable height. There are many ways to shape a gentle curve, including with rasps or spokeshave. Given that the chop is over 6″ wide, and the round over is largely in end grain, I thought rasps might be a bit much like work. Instead, I worked across the width of the chop with a sharp low-angle block plane. This is a very effective way of working, as the low cutting angle leaves a clean surface on end grain, and removes material in a very controlled manner. I used two (freshly sharpened) block planes for this task – No60 1/2 to remove most of the material, and a No102 for the final finish cuts, although you only really need one providing you stop to resharpen before taking the finish cuts. The technique is essentially to remove the aris left at each side of the previous cut, which increased the number of facets forming the roundover, and simultaneously reduces the size of each facet. Eventually, the facets become so small that they are imperceptible. Skewing the plane, and taking a light cut, reduces the risk of spelching the far side of the workpiece.

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Taking a fine finishing cut with the No102

If facets really offend you, then following up with a cabinet scraper or sandpaper can smooth the surface – I used a scraper to smooth things out, although I did not try to obliterate all evidence of facets.

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The shaped vise chop, and the two block planes responsible

Once I was happy with the round over (and this is very much a case of “if it looks good, it is good”), I removed the chop from the mounting hardware and scraped the show surfaces to remove any workshop rash, and chamfered the edges with the Philly Planes chamfer plane. To chamfer the round over I used an Auriou 13 grain rasp, although a spokeshave would also do a good job.

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Chamfering the corner of the round over with a fine rasp

As a final step, I glued the crubber to both surfaces of the leg vise, using contact adhesive and clamping the vise tight together to hold the crubber in place while the glue cured. A sheet of cling film between the vise jaws stops the jaws being stuck together by any squeeze out. Once the glue has cured I will oil the vise chop, and trim the excess crubber. Then it will be onto boring holdfast holes and the planing stop mortise. At this point, completion of the bench is definitely in sight, with only a few weeks’ work left to go.

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Gluing the crubber in place – cling film stops the two layers of crubber sticking to each other