Thread: Corse Buffing Compounds: Status Report

Originally Posted by Belegnole

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I just spent the day looking locally for a 6" 1700rpm grinder with not much luck. Bill is right (not that I would argue with him) though You can buff with a 3450rpm motor. You just have to be a bit more careful with the heat and safety.

Junk washing machines are an excellent free source of 1750 rpm AC motors. (Usually the motor is still good and something else on the washer breaks.) You only need about a 1/4 to 1/2 hp motor for buffing, so don't look for grinder motors...

Originally Posted by fritz

Junk washing machines are an excellent free source of 1750 rpm AC motors. (Usually the motor is still good and something else on the washer breaks.) You only need about a 1/4 to 1/2 hp motor for buffing, so don't look for grinder motors...

That's a great tip fritz.Thanks.

Wow... Somehow I missed this thread. This is my deal. I tend to use the stainless and white polishing compound which tends to be made of aluminum oxide but there are several white "rouges" as it where. But I would suggest that most of you guys use a dremmel with a flex shaft because it is easier to control and far less likely to rip the blade out of your hand and take off finger tips or, worse, destroy the blade. I have a 6" and an 8" pedestal buff for this stuff and I usually use my dremmel.

If you guys want to know what works best, call the guys at English Custom Polish. They will walk you through what compounds to use and how to do it.

I actually just wanted to bring this thread back to life as I always read so many good tips and talks about the polishing and buffing.

It seems I never hear talk of the 'Surface Feet Per Minute' or SFM. If followed properly you can calculate the ideal dia of the wheel to be used for a particular material.

SFM relates to the distance in feet that the workpiece surface or cutting edge travels in one minute.

There's a simple math formula for this.

SFM = 1/4 of the wheels's diameter * arbor speed.

The ideal SFM for Stainless Steel is around 8000 sf/min. Plastics go from 1200 to 4000 sf/min.

When buffing with speeds over 5000 sf/min you get into 'molecule migration' territory. In short, molecules start to move around and this is what cause the heat generation which can become to excessive.

For example If you are using a 3600rpm polisher and by using a 10" wheel = 1/4 of 10 inches = 2.5 inches * 3600 = 9000 SFM.
A little high. It could pass but by chosing an 8" wheel it becomes (2 inches x 3600rpm) 7200 SFM. It's lower but it could work too.

Now you con easily use an 8" wheel on an 1800 RPM polisher = equals 3600 SFM. It's far from the 8000 needed for steel. Difference is it will take you much much longer to get the desired result but at a safer usage.

Off course no one says you need to follow this procedure but it can give you an easy and rough estimate as to what wheel to use.

I tend to use my 1800 RPM for buffing, the 3600 for polishing and my dremel which gets most usage.

I always wear safetly glasses, special gloves and a leather apron at all times when using my polishers/buffers.

I have a grinder/buffer coming in the mail. I also have flap wheels coming and will also hand sand some. What compound should I start at if I am stopping that sanding at 400 let's say?

I have found the 120 grit I use cuts more like 400 grit flapwheels. The 220 is like 400 grit hand sanding.