Metal spinning is a process that is a fun thing to do on an adapted wood lathe, although it can be frustrating if you are not getting it at first. The first step that you need to take is acquiring and prepping your metal spinning tools.
Once you have a combo tool, you need to make sure that it is buffed and polished and ready to be used. If your tool does have scratches or gashes in it, the metal will be more likely to catch and tear as you are spinning it. This is where polishing comes into play.
I am using the equipment at Techshop to do my spinning, as well as the polishing in this instructable.
Step 1: Gathering Supplies
- Combo Tool that needs polishing
- White polishing compound
- Spiral Sewn Buffing Wheel (8" for a 3600 RPM)
- Bench Buffer/Grinder
- 80 grit and 120 grit sand paper
- Orbital Sander ( Optional)
- Proper Safety Gear ( Glasses)
Step 2: Sanding the Combo Tool's Tip
You want to use the sand paper and orbital sander to quickly even out the scratches or gashes that are on the combo tool.
I started by clamping my combo tool down and then doing one pass over the entire rounded tip (the part of the tool that will be contacting the metal) with the 80 grit sand paper.
I then switched to 120 grit and did a second pass to even out some of the deeper scratches from the 80 grit sand paper.
I did not even sand the flat part of the combo tool, because in my case it was dull, but did not have any major scratches in it. With the condition of my tool, I could just skip the sanding on the flat part and only polish it.
As a precaution, whenever using tools generally for wood on a metal object, make sure to clean out the filter, bag, or evacuation system very well! Do not risk hot metal mixing with the sawdust.
Step 3: Polishing the Tool
You need to make sure that you have the proper wheel size to create the correct SFPM (Surface Feet Per Minute) for your material. In my case, I needed around 8000 SFPM. I was able to use this nice chart to figure the right wheel for the speed of my bench buffer.
Before you start polishing, you must apply your compound to your wheel. While the wheel is spinning, slowly push the compound into the wheel until it has a thin layer. It is better to apply only a little compound, but often, rather than a lot of compound all at once. If there is too much compound, it will not be as efficient of a process.
Now you are ready to start polishing the tool. I would start the tool at about 7:00 on the wheel and pull it up to about 9:00. Perform this same motion on all sides of the combo tool until it is a mirror finish throughout. For each pass I did on the tool, it was only touching the wheel for 2 or 3 seconds before pulling off to start a new pass.
Once finished, wipe off any excess compound with a rag, and admire your own image in the reflection of your work.
Step 4: Done!!!
Now that you have that mirror finish, you are ready to get back to metal spinning.
Make sure to label your buffing wheel with the type of compound you used, as you shouldn't use different types on the same wheel.
The metal spinning tool will occasionally get scratched up through normal use, so polishing will be a part of regular maintenance for these types of tools.