Reinventing the Rasp?
Rasps are a staple in most woodworkers tool boxes (or apron, if you’re that kind of guy). Whether you are shaping table legs, or just trying to wedge a junction box into some drywall, they are a great way to remove a lot of material quickly. Most people buy a Buck Bros set from Home Depot for $9 and call it good for the next 20 years. And there is nothing wrong with that for the majority of people. However, if you are ready to step up from Buck Bros, or even $200 hand stitched rasps, read on.
Traditional Rasps
Narex hand cut rasp close up.
Like most things, you can spend a lot or a little on a rasp. I’ve always liked Narex tools, so I’ll use them to explain what you get for your money. If you click this link you will be able to purchase a set of three Narex rasps for around $56. OR you can click this link and buy one Narex rasp for about $100. Many of you already know why one rasp costs twice as much as a set of three from the same manufacture. The $100 rasp features “hand cut” teeth. Hand cut teeth aren’t more expensive because they’re prettier, they are more expensive because they are better. Let me rephrase. Hand cut teeth are more random. Both in depth and placement. This randomness leads to a smoother finish compared to traditional machine cut rasps. Unfortunately the process to make these random, hand cut teeth is obviously more time consuming and expensive. Teeth cut by a machine have those predictable grooves that leave deeper gouges that will take a lot longer to remove when it comes time to sand.
next generation rasps
Kutzall fine rasp in half-round
So how do we get a random tooth rasp for the cost of a machine cut rasp? The answer is pretty obvious really. Well, obvious if you own a third generation carbide abrasive factory. Kutzall has been around a long time and I was most familiar with them for their carving discs for angle grinders. They essentially bond a bunch of tungsten carbide bits to a steel disc. What results is a super aggressive carving tool that essentially never gets dull or looses its temper. Recently they have brought this same technology to a line of rasps. If you are paying attention you can probably already see the advantages. You get even more randomness than hand cut rasps, and as an added bonus you get teeth made from tungsten carbide instead of steel. Generally carbide edges last 5-10x longer than steel for comparison. The carbide bits are also omnidirectional. Meaning they can be used in both a push and pull movement. Unlike traditional rasps that can only be used in one direction.
The Kutzall coarse rasp close up. You can see how random the pattern is, and how it would work in any direction.
But do they work?
They actually work even better than I’d expected. I thought there would be issues with clogging when I first saw them. After 20 minutes of rasping there was just a slight build up in the teeth. Which was easily removed with a wire brush. Compared to my hand cut Gramercy rasps they were a dream as far as clogging and material removal.
The carbide abrasives were also quite sharp compared to steel rasps. Particularly on their coarse rasp. Not so sharp that you are going to draw blood, but you could definitely give yourself a road rash type scuff pretty easily.
Like traditional rasps, Kutzall rasps range from coarse to fine in a variety of shapes and sizes too.
any downsides?
Rubber handle on the Kutzall rasp.
One thing I am not crazy about is the handles. They are a pretty cheap rubber sleeve that doesn’t give you much leverage. I ended up putting my hand on top of the rasp to even out the pressure. The teeth are so sharp that you’d peel your skin off pretty quick without a glove. And similarly you can ruin a glove in no time, the teeth are that sharp. I’d like to have a nice contoured wood handle, but that would obviously come at a cost. So I guess I’d like it for an added price of… $8. That seems reasonable. Who knows, maybe I’ll get motivated and make custom curly maple handles for my set.
so are they worth it?
I have so far only used three of the Kutzall rasps (two fine and one coarse) on one project. However it was a fairly substantial project that required a lot of material removal. I have about two solid hours of use with them and I would say that I am sold. I’d love to see some more shapes and profiles. Maybe some curved shafts, or even small riffler type rasp sets. Currently they only offer flat and half round profiles available in two lengths. All available in both coarse and fine. Originally I thought there might be a gap in between the coarse and fine, but after my testing I feel comfortable with just the two grits.