Before I can sharpen my backsaws, I need to make two things: a file holder for jointing the teeth and a saw vise. I was going to post both of these items together, but I think the file holder deserves its own post. A file holder is also useful for jointing hand scrapers. Some people don’t bother with a file holder and just hold the file with their hands, but it’s easier to keep the file perpendicular to the teeth using a holder with a fence that rides against the side of the plate. I’ve seen a design for a holder that uses a wedge instead of a clamp, but personally I think the clamp is a better solution. There are some vintage file holders that surface on ebay from time to time and Veritas also make a aluminium (aluminum in the US) holder if you don’t fancy making your own. I can guarantee that this one is more comfortable to hold though.
I did a quick drawing in Sketchup to work out the approximate dimensions. The body is 44mm by 44mm by 190mm long.
Here’s an x-ray view so you can see the holes I need to drill. I actually ended up using four bolts instead of the three you see here. Also, these holes are for M6 bolts and I ended up using M4 bolts.
Scavenging around in the scrap pile, I found an off-cut of sapele that would work for the body and some hard maple for the clamp.
I marked out where I needed to cut with my marking gauge, then used my router with a straight bit to cut the channels in the sapele.
Here’s the first channel done.
Then I rotated the wood 90 degrees and cut the second channel.
Sawed out the waste…
…and trimmed it to length.
I planed the ends down to my scribe lines…
…and smoothed all the external surfaces.
After that, I eased all the external edges with a file.
For the top and the outside of the fence, I used the router again fitted with a round-over bit.
I’m probably missing a couple of photos here, but I basically cut out a piece of hard maple for the clamp and re-sawed it with my rip backsaw and planed it square. I used the dowel you see clamped to my Workmate as a planing stop. I plan to use two files with this holder and one is slightly thicker than the other. I used the thicker of the two as a spacer to size the maple.
Next I planed a chamfer along one edge of the maple clamp to provide clearance for the set of the saw teeth.
Now it was time for the drilling. I’m using 20mm long M4×0.7mm pan-head bolts. So I gathered together the drills and the tap that I needed and wrapped blue tape around each drill as a depth gauge. After laying out the positions of the holes, I pricked the centers with my awl.
First the 8mm counter-bore to create a recess for the pan-head.
Then the 3.3mm drill which is the internal diameter of an M4×0.7mm thread.
The maple clamp was taped in position when I drilled the internal thread diameter holes and I set my depth to go straight through the sapele and just mark the position of the holes on the maple. This also prevented any breakout on the underside of the sapele.
It was then easy to pick up the holes and drill my 4mm clearance holes.
Next I tapped the M4×0.7mm thread. Since I’m cutting the thread into long grain and the bolts won’t be constantly unscrewed and re-tightened, there’s no need for brass inserts here. Cutting the thread directly into the sapele is plenty strong enough, because you only need to cinch up the bolts to provide sufficient grip. Friction will do the rest.
I knew I would have to file the bolts down a bit, but I did a test fit first to find out how much I needed to take off the length. It turned out it was 2.5mm.
So I set my adjustable set square to 17.5mm and filed down the bolts until the distance from the underside of the pan head to the end of the thread was 17.5mm. Now the heads are recessed below the surface like I wanted and there is still enough clearance under the heads to allow for adjustment in and out.
And that’s all there was to it really. The file is held very firmly. I tried really hard to make it slip, but I couldn’t move it.
Sapele is an open-pored wood and I think the open pores improve the grip, so I didn’t want to apply a surface finish like a varnish that would only fill up the pores. So I dismantled it all again and wiped on a of coat of Liberon Finishing Oil followed by a coat of wood balsam. Anyhow, here’s the finished file holder complete with file, ready for action.
This holder works equally well for right or left-handed use (I’m predominantly left-handed). If you’re right-handed, you simply put the file in the other way around. I made it long enough to allow for a two handed grip as shown below. The heel of my left hand is providing downward pressure to the back of the file and my left thumb is providing lateral pressure to keep the fence riding against the side of the saw plate. My right thumb
is putting downward pressure at the front of the file and the fingers of my right hand rest on the underside of the fence to provide stability.
I’m really pleased with this little holder. It’s comfortable to hold and affords a very positive filing action whilst keeping your hands away from the teeth of the saw. So, if you don’t already have one, why not dig around in your scrap pile to see what you can find to make one. The trickiest part was drilling the holes accurately with a hand-held drill. If you have a pillar drill with a depth stop though, it should be a piece of cake.
I’ll get on and make the saw vise now.
-- Andy -- Old Chinese proverb say: "If you think something can't be done, don't interrupt man who is doing it."