Sanding fast

This page is about basic sanding but with help to speed things up. There are a number of sanding attachments that may be purchased. I have a couple of non motorized sanders which allow the sanding disks to turn as the paper is held against the turning wood, however these sanders will not remove wood very quickly. I have resorted to power sanding. A drill works well for this but the small 4 inch angle grinder designed to rotate at 11 000 rpm is the fastest wood remover. (The 4 1/2 inch angle grinder does not rotate as fast, but it has more power.) The downside to a off the shelf grinder is the 4 inch disks are not suitable for getting into tight spaces when sanding on the lathe. So I have "adapted" the angle grinder to use 2 and 3 inch "roloc" disks (from the auto industry) and velcro disks sold for passive sanders. What follows is an explanation of how these angle grinders are adapted and used.

One note of caution: The angle grinders produce a LOT of dust when they are used, too much for my dust collector to handle, so I use a fully enclosed respirator. If you do use this system you must find a way to avoid breathing dust.

Basic sanding practice.

Start sanding with the highest grit number that will allow smoothing the wood of tool marks. (Coarse grits leave lines on the wood that need to be removed with ever finer grits).

Increase sandpaper grit number by half: If you start with 100 grit then the next grit should be 100 + 50 or 150 grit. If you start with 80 grit then the next grit should be 80 + 40 or 120 grit. I generally use the following grits: 100, 180, 220, 400, 800, and 1200. Often I start right in with 180.

Strive to create a cross hatch pattern which will be easily removed by the next grade of paper.
If you do use non powered sandpaper try using blue or pink foam as a pad as this will melt with heat and mold itself to the shape you are sanding. Not too much heat though, you do not want to burn the wood or the sandpaper.
 

	I have always disliked sanding and have resorted to power sanders of one sort or another. This is about the best. Connected to a dimmer switch to control speed this 4 inch angle grinder equipped with auto sanding disks of the "roloc" type. The sanding devices can be easily changed with the hand tightening chuck. These items cannot (to my knowledge) be purchased together so I bought the angle grinder  for $19 and the chuck for $9. Threaded the chuck with the same TPI as the grinder and screwed them together. Chucks are not available with the matching threads but a 3/8 thread is close to the right size, so I just re-thread holding the chuck on the lathe and the tap centered with the tailstock. There is a little vibration but a more expensive grinder may not have any, I will test it some time with my Makita.
	To tap the chuck you must set it up in the lathe. Here is a rod mounted on the lathe for the chuck to be mounted on. Tighten the chuck to be tapped onto this rod, insert the tap and center the tap with the tailstock. (I used a metric 10 X 1.25 tap which matches the threads on the spindle of the Princess Auto Powerfist brand Angle grinder. Makita has the same size spindle on their 4 inch grinder.) I tried to tap the chuck free hand but it was too hard to get the threads true. This technique will help ensure the chuck runs true on the angle grinder.
	Here are two grinders ready for sanding each hanging in its own wire holder. These grinders are plugged in to a dimmer switch which allows me to control their speed. About 800 rpm for the "roloc" disks and 500 rpm for the velcro disks. The roloc disk holder is screwed right on to the grinder as I have retapped the back of the holder with the same technique as described above. You have to drill out the hole before tapping as it is only 1/4 inch.
	Here are the disks ready to use. Discard them once they are worn. I use the 80, 120, 180, Roloc disks followed by the velcro backed 220, 320, 400, 600, 1000.
	Here is the Triton brand respirator connected to a hose which brings fresh air from elsewhere in the house. I use a computer ventilator fan to drive the air. There is a screw eye in the top of the respirator to allow it to be stored close at hand. It hangs from a wire hook screwed to the ceiling.
	For some applications this foredom flex shaft tool works fairly well but it will not handle high rpm. There is an example of a "roloc" style disk here. (I buy mine in packages from Princess Auto.) Also in the picture is the device used to control the speed. A simple dimmer switch connected to a duplex receptacle. Plug in any small brush motor and you can dial the speed you need. (Angle grinders and routers may be controlled this way.)
	Left is a nut and bolt silver soldered together to make an adapter to allow mounting a 1/4 inch threaded disk onto the Angle grinder which is threaded 10 X 1.25 metric.