I recently bought a set of rasps from Corradi (Italy) for review, and they came without handles. That wasn’t a surprise and this isn’t a complaint. We’ve gotten used to high end manufacturers adding fancy handles to the rasps they sell, but fancy handles add additional cost. Corradi decided to stick to the metalwork, pass the savings on to you and let you figure out what to do with it. For testing purposes I grabbed an old Nicholson handle from another rasp in my collection and it worked fine, but I knew that it wasn’t a long term solution for these wonderful tools. My full is currently available on the Popular Woodworking website but, to make a long story short, it was immediately clear to me that these Corradi rasps (particularly the GOLD cabinet rasp) had earned a place in my workshop and that they had also earned some proper handles.
Making handles seems intimidating if you’ve never done it but there are several good options. If you don’t have a lathe, hand shaped octagonal handles are easy to make and have a long and illustrious history in the tool record. If you choose to go that route let me recommend this excellent blog post by Zachary Dillinger. He’s hafting a chisel, but the principles are tranferrable.
If you do have a lathe, turned handles are also a great option and the one I generally choose, so let me walk you through that process.
It all starts with a chunk of wood, and wood choice for rasp handles is a largely subjective thing. You won’t be beating on them with a mallet (I hope!) so almost anything will do. Something hard and slick with tight grain makes a pretty handle, but I like something that doesn’t get too slippery in my big sweaty mits. I didn’t want to spend a fortune on exotic wood so I dug around until I found two nice mulberry offcuts in my scrap pile. I squared them up on the bandsaw and got them ready for the lathe. Each blank started as roughly 1.5″ square and about 8″ long.
There is an effective range of handle lengths, so you dont want something too long or too short. Within that range, however, there’s a lot of room for experimentation. I have large hands so I like my rasp handles to be between 6″-7″ long and I like to leave some extra material as waste at the drive end of the lathe.
After chucking one up and roughing out a cylinder it’s time to make some decisions about how this handle will look and feel. I suggest poking around your shop to find a handle you like – something that feels good in the hand – and then take some measurments.
Sometimes I make a story stick or pattern if I know I’m going to be turning several identical handles, but for a single handle it’s easy to mark the major and minor diameters right from the example.
Shape your handle however you like, but here are the dimensions I used:
Overall length: 6.5″
Major dimension (palm): 1.5″
Minor dimension (thumb and forefinger): 7/8″
I like to use a parting tool to work down to those diameters and then shape the handle from there. In order to get the most exacting work out of the way first, I begin with the end that will receive the ferrule.
Speaking of the ferrule, you’ve got options. You don’t technically need one at all for this sort of handle, but they look good and provide extra assurance that you wont split the handle in half when seating the tang. One solution is to buy commercially available ferrules, but you can also make your own from things commonly found at any home store. Copper pipe fittings make good ferrule material. So do aluminum tubes. Look for something you can easily cut with a pipe cutter and shape with files and sandpaper. I like 3/4″ aluminum tubes because aluminum is easy to work with and it polishes to a really nice shine. You can even shape it with a carbide cutter (although it will dull the edge of the cutter pretty quickly).
Fitting the ferrule can be a little tricky. You want it to be tight enough that you have to knock it on with a mallet, but not so tight that it’s shaving the wood on the way down. The easiest method I’ve found for setting my caliper is to make a dummy ferrule end with an almost imperceptible taper, fit the ferrule and then set the caliper off of that measurement.
When I’m close to diameter on the handle I take it off the lathe to test it, then put it back on to refine the fit. Rinse and repeat until satisfied. (It’s easier to take wood off than put it back on.) I also put some ridges in the wood and add a slight undercut where the ferrule meets the shoulder to ensure a clean snug fit.
The next step for me is usually drilling the hole for the tang of the rasp. Ive found two ways to do this well but both involve using a Jacob’s chuck on the lathe if you want to make sure it goes in nice and straight. One method is to drill one hole to depth with a brad point bit sized to the thickness of the tang and then drill a stepped hole (about 1/3 depth) with a larger diameter bit that approximates the widest point of the taper of the tang. The other option is to drill the first hole the same way and then to lean the bit back and forth laterally to widen the hole. Make sure to widen the hole with the grain and not across to avoid splitting the handle when you drive the tang. Both methods work. The later looks a little better in my opinion. Adhesives are unnecessary.
With that done, its really just a matter of bringing everything into shape and refining it until it looks and feels good. Some 220 sandpaper finishes things up nicely but I sometimes go up to 600 or 800 to polish the ferrule. I usually finish handles with boiled linseed oil, homebrew soft wax or a simple burnishing. You dont want anything too slick.
Carefully (but firmly) drive the handle onto the tang with a rubber mallet and rasp to you heart’s content.