Acoustic Guitar Construction

For those of you out there that use buffers, what manufacturer and grade compounds are you using to complete your work? I recently purchased Menzerna Medium and fine and was wondering if I should be using x-fine?

Hi, Tim!

For buffing compounds, wheels, and other supplies, the overwhelming majority of my business is done with Mike Caswell (Caswell Plating in Lyons, NY).
Although I do have (very limited) experience with the Menzerna line, I am not qualified to state which of their products is appropriate for specific applications simply because my experience with them is so limited.
So please keep in mind that when I speak of the process I use with the Caswell products; it's not to say "this is better than that", but rather the method that has worked best for me.

1. Sand to 600 grit.
2. Use "Plastic Buffing Compound P-112" (fine).
3. Use "Plastic-Glo P-22" (ultra-fine).

No matter which brand you use, the procedures will remain the same for plastics, finishes, and wood. A lot of people have experience polishing metal parts, but fail to realize the rules change slightly when going to a finish. The material you are buffing will determine the type of wheel, type of compound, and wheel speeds you should use for best results.

I like to classify my materials into:
Ferrous metals (steel and iron)
Stainless steel
Titanium
Copper, brass, aluminum, zinc
Gold and silver
Hard platings (nickel and chrome)
Platics, finish coatings, and wood



If you're new to this, here are "the basics" for finish coatings, irregardless of whose compound you use.
1. Sand up to appropriate grit. This will depend upon which compound you use, and is best determined either through experience or consulting with the manufacturer.
Lots of folks use only one final buffing compound, so they sand to higher grits before buffing. Whereas those who use more than one grade of compound can usually get away with sanding to a lower grit.
2. Use Canton cloth for the wheel material. If you can obtain a string wheel, even better.
3. Use a dry to very-dry compound.
4. Do not use different compounds on the same wheel.
5. Ensure that the buffer is running at appropriate speed. This is where a lot of people get frustrated and blame either the compound or their technique. For buffing out lacquered finishes, etc. you're best off keeping the wheel speed well below 3500 SFPM.
This means if your using a 12" wheel, your shaft should be no faster than 1100 RPM. If you do the common method of attaching a large wheel directly to a motor spinning at, say, 1750 RPM, you're probably gonna get frustrated. With the shaft running at 1750 with a 12" wheel, your suface speed is about 5500 SFPM! Great for steel, not so great for finishes.
6. Above all, BE CAREFUL & STAY SAFE.

If you need to experiment to find out if your particular combination is going to give the results you want before you put your prized baby (the guitar) to the wheel, a great practice run is to try things out on a scrap piece of plexiglass.

Hope it helps,
Rob

Thanks Rob. I bought my buffer from Caswell a couple years ago (1100 RPM buffer kit) and have been using the compounds that came with the kit since then. On the first 5 guitars it was OK but I wasn't real happy with the shine I got. Also used it to buff a number of other guitars. Thought it may be my technique. Didn't want to buy more compound if I didn't have to because what I had would last so long. Well to make a long story short I went ahead and got the Medium and Fine (16 and 18) Menzerna compounds. They came today and I used them over a buff I just did. The difference was really noticeably better. Now I feel it was not so much my technique but the compounds I was using 'm really happy how today came out and hope things stay that way. Don't think I'll need that x-fine compound.