As mentioned elsewhere, my workshop is tiny. I’d love to have more space, but right now that is not an option. In consequence, I do not have the space for a separate disc sander. But, what is a disc sander anyway? It’s a spinning disc with some way of attaching sanding paper to it, and ideally it has a sanding table so that precise angles can be sanded.
Right, here is the first part: a disc sander:
How it’s made: figure out which maximum size sanding paper you can get. That determines the diameter of the disc you need to cut from plywood. Buy a suitable faceplate. I think mine is an 80mm model, with 4 screw holes, but bigger is generally better. Find the centre, and screw the faceplate to the plywood disc. Make sure you use screws that don’t protrude on the front, otherwise you’ll have to file them off. Mount the whole thing on your lathe and turn it round and flat (no kidding, not all plywood is completely even, and your disc sander will work a lot better if the surface is completely flat, and don’t ask me how I know that).
Once flat, you can seal the wood with some sanding sealer or varnish or both.
There are two types of sanding discs available on the market. The one type is self adhesive on its own, the other type is velcro backed. I went for the velcro-backed type, for several reasons:
- It’s a 5 second job to change the sand paper.
- I only have to make sure once that the backing is put on without any bubbles.
Now buy a self adhesive hook-and-loop pad (Axminster). They are a little pricey, but if you are careful, they will last a very, very long time. Stick it onto your disc, making sure it is properly centered and there are no bubbles anywhere. You want a completely flat surface. Now you can stick any velcro-backed sandpaper onto that.
I use mine mostly with 80 and 120 grits, and usually at speeds around 500rpm. Any faster and your work piece will heat up quickly (and you don’t want that, it can lead to heat checks, which are nigh impossible to get rid off). Any slower, and you are losing efficiency. Be warned: a disc sander with brand new sand paper on it can make substantial amounts of dust in next to no time at all.