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buffing with a 4" grinder
http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=27850		 Page 1 of 1
Author:  alan stassforth [ Tue Jun 15, 2010 10:49 am ]
Post subject:  buffing with a 4" grinder
hey, i want to get a better finish on my builds, but don't have the funds or room for a real buffer.
i have a 6" handheld polisher ( no way will that ever come close to a gitar) and a little makita 4" grinder.
i think i might be able to get a polishing set up for the makita. anyone tried this? or should i just keep polihing by hand? ( i always seem to burn out and say it's good enough, when it ain't really :oops: )
i tried searching older posts here, and couldn't find anything.
Author:  Mike OMelia [ Tue Jun 15, 2010 11:47 am ]
Post subject:  Re: buffing with a 4" grinder
Is it speed controlled? You won't want speeds above 1100 rpm (and that is high as well). Lowes sells a delta grinder with speed control for like $70. Most do not have speed control. But even if it does, I think you will lose a lot of torque at the lower speeds which will limit your wheel size. Then there is the issue of working close to the body of the grinder (ugh!) Be careful. Do you have a drill press?

Mike
Author:  Daniel Minard [ Tue Jun 15, 2010 12:31 pm ]
Post subject:  Re: buffing with a 4" grinder
I have done the job with a big (6" IIRC) angle grinder & a clean sheepskin pad. If you are careful (and gentle) you can pull it off.
One problem is they spin so fast, they throw polish everywhere. Works better by appling polish to the guitar, rather than the buffing pad. Is the neck on? It's much trickier if it is.
Work away from the edges. At the high speed, it'll burn through quickly if you catch an edge.
You'll need a way to hold the guitar firmly while you're buffing. Also... a separate pad for each grade of polish.
Author:  Tai Fu [ Tue Jun 15, 2010 1:05 pm ]
Post subject:  Re: buffing with a 4" grinder
I know a power drill will work pretty well if you rather not buff by hand. In fact stewmac sells buffing pads designed to be used on a power drill. I used it in a drill press with decent result. Even the highest speed on most cordless drill isn't fast enough to burn through anything, but the problem is my cordless drill kinda winds down due to its crappy battery. I might get a corded drill some day.
Author:  alan stassforth [ Tue Jun 15, 2010 1:53 pm ]
Post subject:  Re: buffing with a 4" grinder
thanks for the info guys.
hey mike, i do have a drill press.
have you used one for polishing?
what's the basic set-up?
what size disc would work?
Author:  Mike OMelia [ Tue Jun 15, 2010 6:31 pm ]
Post subject:  Re: buffing with a 4" grinder
viewtopic.php?f=10101&t=21724&p=301164&hilit=drill+press+buffer#p301164

Look at that link. The picture is of my first cut. 14" wheels. My speed control is infinitely variable and the readout tells me where I am in rpms.

The final version had another bolt coupled to it and held in place with a bearing in a block of wood. The block of wood was clamped to the drill press table. I think (minus the wheels) I had about $30 in it. Got all the parts at McMaster Carr. It worked great. You need the bottom support to prevent the bolt from flying out of the chuck (it never happened, but then again, I did not want to be near it if and when it did). Lining it all up was really easy. It tends to be a bit cramped spacewise and you really need to think through your moves.

I used it on a couple of guitars and then moved on to a Grizzly buffing arbor... bought a 1/3 hp motor somewhere and built up my own rig...like it a whole lot more.

If your chuck is weak or not very stable, I would not go down this path. And if you did go down this path, I would not stay on it long... no sense in ruining your drill press bearings. But, the bottom shaft and bearing does help keep lateral stresses to some minimum.

Mike
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