Teardrop Scraper

I’m shaping metal, and I don’t really know what I’m doing. I’m using a Dremel to cut chunks out of a perfectly good card scraper. I’m not sure this is the right wheel for the job. I’m having a hard time getting the shape I want. Let’s see how it turns out.

My chair from the stick chair class has been languishing in my workshop. The class was frantic. There are a lot of little bits of tear out I want to fix up along with little glue splashes. It’s been cold, my enthusiasm for getting into the workshop has been low.

Trying to clean up a fully assembled chair is not easy. I have just enough space to have the chair in the shop. Positioning it to get at every spot it difficult. I was on fine-tools picking up some odds and ends, when I spotted a little teardrop shaped scraper. It looked ideal for cleaning up some of the more difficult spots. I added it to my cart. When it arrived, I realised I’d ordered the wrong one. Still a handy shape, but not what I wanted. I have a bunch of spare scrapers. I decide to make my own teardrop scraper.

I’m fond of small scrapers. I have a pack of 4 made from crown tools. The little concave one comes out a lot for refining curved pieces. A teardrop would make a great addition. I picked out a scraper on the thinner side. Then used some plastic French curves held up against my computer screen to very crudely sketch out a shape on the scraper (I have no idea how you are supposed to use french curves, but I find them handy for this kind of thing). I’m all in on hand tools for wood, but draw the line at metal. Out comes my rarely used Dremel. I pick something that I think is a cutting wheel, and go to work.

If you are precious about your bench, find somewhere else to do this work. Metal dust gets everywhere. I don’t have enough space to be precious, so I go straight at it.

It may have been better to go with a hacksaw. I’m fairly sure any time I gained with the Dremel, was lost to cleaning up places where I wandered off line, or it skipped in the cut. Cutting out half the scraper eats an entire wheel. Then I switch to an abrasive bit in it to work the inside curve of the teardrop shape. That is slow going. Using either generates a lot of heat. I’m very worried that the scraper is getting cooked, and wont take an edge when I’m done. I decide to leave a lot of extra material to hand file off. With a little luck, if I have cooked the edges, I’ll file past it later.

With the inner curve shaped, I cut the rest free. I turn to my bench grinder to smooth out the outside curves. It’s a very small piece of metal. Its taking on a lot of heat very fast. I stick with the plan of getting the rough shape right, and leave lots to file.

Looking at the shape I’ve produced, Its far from what I was aiming for. But the core attributes I want are there. A long pointed tail for getting into difficult spots, and a larger gently curved portion so I can work slightly larger areas without having to switch to a different scraper. It will be an ugly duckling, but it might still work.

After the grinder its on to the files. The horror show of my work with the Dremel became more apparent as I filed off the scraches to get a clean surface. It takes a fair amount of work , but its becoming more and more presentable as I work.

Once the perimeter is filed, I move on to the stones. The inside curve gets worked with a pair of oilstone rods. One 120 grit, the other 3000 grit. I get a nice clean surface with no visible scratches. There is no easy way to give those rods a guide on the inside curves to make sure I’m creating a square edge. I hold the rods on both ends and use the middle to work them. That gives me a decent visual reference. Work until the scratches are gone and hope for the best.

Then I use a 600 grit and 1200 grit diamond stones on the outside curves. Easy work. Using a block of wood on the stone lets me be confident that the outside edges will be at 90. If the outside of the scraper is good, but the inside is not, it will be a pretty useless tool. Fingers crossed.

Time to flatten the faces. I have some diamond paddles for knife sharpening jigs. I like to put scrapers on a flat board, and then take the paddle to the scraper. It’s quick, it’s easy to apply even pressure, but it does not look pretty at the end. Overlapping passes are visble but I find it makes no difference to the result. Some of the discolouration that made me worried I had cooked the steel comes off very quickly. This might be OK.

The last thing to do is to turn the burr. Disclaimer Time: I’m on Union’s board of directors, anything I say about the Accu-burr should be taken with the same weight as someone telling you how awesome their kids are.

For me, its completely unbeatable for a task like this. The scraper can sit as high in the vice as you like, you bear straight down when turning the burr. You do not need to worry about it flexing from lateral pressure and messing up your angles. If the scraper starts to flex and wobble, that means you are not holding the Accu-burr perpendicular to it. Keeping a tiny scraper like this low enough in the vice that you can keep a consistent angle as you work across it with a traditional burnisher would be very challenging. I work all the way around, my fingers are detecting a decent burr.

I break out a board of Sapele and start testing the outside curve. I work all the way around, and I’m getting nice shavings. Then I take it to a few spots on the long sticks on my chair, the inside curve gets put to work. I cant find any spot where I’m not getting shavings as I work it.

The teardrop shape is working well. I can effectively get shavings with the very tip of the tail, and I can work into awkward spots I’d never get other scrapers into. I spent a happy hour going at the chair, using the scraper from all kinds of angles, and the burr holds up. I have not cooked it.

Its an ugly duckling, but its a very useful ugly ducking.

The wrong scraper. A very handy shape, but not what I wanted. The teardrop, top left, is what I wanted. Using the french curve here to help sketch it out. The donor scraper with the shape roughly sketched out. Out comes the dremel. I have no idea what kind of wheel thta is, but it did the job. If you have not cut metal this way before, it is not as scary as it looks. The sparks can go right on your bare skin. You will not feel a thing. In this shot the scraper is way too high, flexes too much as I try to cut. Inside curve is largely free. I stopped here to shape it more. Easier to hold in the vice at this point, and the rest of the metal can help as a heat sink. Used a grinding bit on the dremel here. It works. Its a bit slow, probably not much fast than just filing. Thats the inside roughed out. Over to the grinder to refine the outside curve. This is looking pretty rough. It is around now, I think this may not work out… Cut the rest free. You can see some of the discolouration that makes me think I’ve cooked the steel. Out come the files. Round file for the inside curve. As I file, it begins to start looking a little more respectable. From the files to the oilstone rods. You need to look out for stuff like this. That depression will not let a burr be turned. It needs to be worked out. After flattening the face. Turning the Burr And it works! Here is the kind of spot its hard to get to with a normal scraper, or even sandpaper. Glue and scratches I want rid of. A little quick scraping with the tear drop and its looking a lot better.

A video showing the outside faces scraping.

And the inside faces working a long stick on the chair.