Polishing on a bench grinder?

[choochoo_balooParticipant @choochoo_baloo]

[choochoo_balooParticipant @choochoo_baloo]

I always receive helpful replies to my beginner questions, so here is a new one!

Whilst cleaning up various tools, I am starting to notice the limitations of fine abrasive and then rag and polish.

Having watched home machinist videos and doing some reading, I think that the next step is a polishing kit to fit to a bench grinder, much like this one;http://www.axminster.co.uk/heavy-duty-polishing-kit-for-steel-stainless-steel-ferrous-metals-503938

Thus can others answer the following:

1. Can a mop disc kit be fitted to any bench machine regardless of whether it is labelled a "grinder" or "polisher". Are they actually the same machine ignoring the wheels fitted?

2. Assuming answer to 1. is 'yes', is there only one size of pigtail arbor, i.e. all polishing mop discs just push fit onto the pigtail?

3. Can anyone recommend machine models, or (for a mild hobbyist) are they all much of a muchness?

Any help gratefully received.

[GoCreateParticipant @gocreate]

Hi

I believe you can use most bench grinders, you need to select pigtails that match the grinder shaft dia, usually 1/2" on small grinders and mop diameter/width that match the grinder power rating.

You can find recommendations for mop sizes relative to the grinder power rating here. I've no connection other than being a customer.

Nigel

[thaiguzziParticipant @thaiguzzi]

Get the biggest motor you can afford. A 1/2 hp polisher with a 6-8" mop on, i can stop dead. You want a minimum of 3/4" hp, preferably 1 hp.

[richardandtracyParticipant @richardandtracy]

I got a 'Power Devil' 180W 6" bench grinder years ago (early 1990's when sold by Screwfix). Earlier this year, the coarse wheel was down to 3.5" diameter & the fine wheel down to 5.5" dia, so I took a look on the web to decide whether it was cost effective to replace the wheels or the grinder. I found a new grinder was only about £5 more expensive than a new pair of wheels. So I got a new grinder & put an Axminster plastics polishing mop set on the Power Devil. I will confess that for plastics, the Axminster polishing set is a bit brutal & can polish in grooves into the plastic if I'm not careful. Should be perfect for soft metals.

I haven't used tails on my mops, I just drilled a 10mm hole through the leather boss & used the grinder nut & a washer on the grinder shaft to hold the mop, which it does very well.

I wouldn't advocate pushing hard enough against the mop to slow it significantly. Polishing occurs best with a high peripheral speed, and should back off if the motor slows much.

Regards,

Richard.

[Paul LousickParticipant @paullousick59116]

Pigtails, mops and cutting/polishing compounds should be available from stores that sell power tools. Select a pigtail to suit the thread on the end of the grinder spindle. Remember that one end has a LH thread and the other RH.

Polishing mops/felt disks can also be attached to an electric drill. I have even mounted a pigtail with mop in the chuck of a lathe.

[not done it yetParticipant @notdoneityet]

can also be attached to an electric drill.

Agreed, but do remember that most drills are only designed for axial loads.

[VicParticipant @vic]

This is a very good supplier, postage costs are low and delivery is quick. They have lots of information on mops and compounds on the site.

**LINK**

[RobCParticipant @robc77385]

The only thing you really need to look at is the duty cycle of the grinder. Many are not rated for the sort of long use that some polishing entails. Mine needs a half hour break every 30mins to stop overheating too much (it becomes a little too toasty at that time)!

I had mine from one of the suppliers linked above and it works well, but what you get is a simple grinder (complete with grinding stones) which you then disassemble to fit your pigtails to. With some searching you can probably find a less expensive one elsewhere (350W is a good starting size).

Be careful where you site the grinder as it also has a tendency to grab things from your hand and throw them about with some force.

The polishing mops also fling fluff around for the first few hours too.

[HopperParticipant @hopper]

YOu can buy polishing mops etc that fit onto a 4" angle grinder and are right handy.

[Jon GibbsParticipant @jongibbs59756]

Have you thought about using the lathe (with a mop on a MT pig-tailed arbor and appropriately covered bed-ways of course) or perhaps better still an old woodlathe.

Most woodturners will use their lathe with appropriate polishing mops and compounds for polishing turned timber items – myself included.

Chris at clickspring **LINK** about 5 minutes in, talks about a buffing attachment for his small watchmakers lathe and I could envisage a similar item could be rigged for more conventional sized parts.

HTH

Jon

[JonParticipant @jon]

Spot on Thai.

Originally 28 years ago I had a cheapish 1/2hp 6" bench grinder. Slightest touch with thin mops motor slows and constantly waiting to pick up speed.
Got given an old 5" Wolf with 1/3 hp motor, half as bad as the Chinese cheapy but less power.

Do have a 3/4hp 8" Draper Chinese and that would struggle with small 4-6" mops and parts.

You have to buy either a Left hand arbor or Right hand harbour to fit the spindle.
Normally its just a case of removing existing wheel and guards and fitting the arbor and away you go.
Equally you could just use any 3000rpm motor and make the arbor.

Do have some where a Viceroy pedestal mop polisher came with 3ph 3/4hp motor that was ok ish, quality counts. Does sport a 3hp 3000rpm motor now what a transformation with 10" mops doing steel work and stainless to 99% mirror. Wont stop this one barely any speed drop with pressure on. As a compare takes 1/2hr that above 1/2hp would still be going at it in 40hrs+ no pun.

Hate mop polishing, aluminiums the worst and too easy to over polish.

[Ian S CParticipant @iansc]

Just be carefull if you use an electric drill with a polishing mop, it is very easy to over load the drill, and also the drill will not like running for more than a few minutes.Same goes for any load on an electric drill, Dad burned out a couple of Black & decker drills with the load from attachments such as circular saw, and wood lathe, and wire brush. We found a sugestion from B & D, don't go above 1.5 inch for turning in the lathe, and only run for a few minutes at a time.

Ian S C

[thaiguzziParticipant @thaiguzzi]

Posted by Jon on 16/06/2017 00:36:00:

Spot on Thai.

Originally 28 years ago I had a cheapish 1/2hp 6" bench grinder. Slightest touch with thin mops motor slows and constantly waiting to pick up speed.
Got given an old 5" Wolf with 1/3 hp motor, half as bad as the Chinese cheapy but less power.

Do have a 3/4hp 8" Draper Chinese and that would struggle with small 4-6" mops and parts.

You have to buy either a Left hand arbor or Right hand harbour to fit the spindle.
Normally its just a case of removing existing wheel and guards and fitting the arbor and away you go.
Equally you could just use any 3000rpm motor and make the arbor.

Do have some where a Viceroy pedestal mop polisher came with 3ph 3/4hp motor that was ok ish, quality counts. Does sport a 3hp 3000rpm motor now what a transformation with 10" mops doing steel work and stainless to 99% mirror. Wont stop this one barely any speed drop with pressure on. As a compare takes 1/2hr that above 1/2hp would still be going at it in 40hrs+ no pun.

Hate mop polishing, aluminiums the worst and too easy to over polish.

Indeed.

Filthy, hard, sweaty job at the best of times. A good polisher can earn good money

All industrial off hand polishing is done using a double ended spindle with a THREE HORSEPOWER motor. They do not slow down for anything. And can break wrists, fingers and destroy components flung off at great velocity in a split second. But Christ they get a job done quick.

I speak from experience as i had a metal finishing shop in my previous life in England. These days i have a Creusen top quality linisher L/H side, polisher R/H side, bought in 03, sold at the time in their "Pro" range, but i'd describe it more as high end "hobby". Certainly would not/ could not earn money with it. I think it is 3/4" hp, the linisher is perfect, but it's under powered for polishing with 6-8" mops.

Edited By thaiguzzi on 16/06/2017 06:03:14

[mechman48Participant @mechman48]

… 'Polishing mops/felt disks can also be attached to an electric drill. I have even mounted a pigtail with mop in the chuck of a lathe'…

​That's what I do for the small amount of polishing I do, I made an adaptor from hex bar for the 3 jaw chuck, turned the end to suit the pigtail dia. simples.

​George.

[Author]

Posts