Metal Polishing
Moderators: John@sos, charlesp, Charles uk, RickUK, Petergalileo
Metal Polishing
Thought I'll do a bit of research on metal polishing and gain some advice. Bought this cheapo kit to get me started before progressing to buffing on a bench grinder. What techniques can you guys advise me about?
Re: Metal Polishing
I have had some decent results on alloy engine casings on my Triumph. Dress out the damage, scoring corrosion etc then use wet and dry start with a medium then move to a finer grit. Then start polishing using medium and then finer paste. Takes a while, but quite satisfying 
Re: Metal Polishing
Hi Hugo - polishing is quite complex to do properly - very first thing is to firmly anchor either the polishing machine you are using, or the workpiece, as you need to apply a fair degree of pressure to achieve anything worthwhile.
Ideally you need some form of dust extraction - even a vacuum cleaner with a strategically placed nozzle will work, and do wear a dust mask.
When polishing, if presenting a part to a bench mounted buffing unit, NEVER put a pinkie through a convenient hole, as this is a good way to lose a finger.
A hand drill might be OK for very small jobs, but difficult to control for anything else.
Small buffing wheels (mops) up to say 3 - 4 inches diameter - need to run at 3,000 RPM to generate some friction/heat- your bench grinder will only be doing approx. 1450 RPM, and the spindles are generally too short to allow manipulation of parts around the mops.
Buffing compounds are different according the type of metal you want to polish - you kit appears to have a grey and a white bar compound - read the instructions, but the grey one is almost certainly for first stage buffing, and the white one is for final buffing. Work up a 'head' of compound on the face of the wheel, and re-apply a little wipe with every few seconds of polishing. On soft metals - e.g.aluminium or brass - the wheel surface will adopt the colour of the metal being worked, which is telling you the process is functioning correctly.
Stainless steel is a tough cookie to polish!!
Before buffing, parts need to be abraded to remove scratches, dings etc., probably going down in stages to 120, 240 and 320 grit abrasive grain.
Rick
Ideally you need some form of dust extraction - even a vacuum cleaner with a strategically placed nozzle will work, and do wear a dust mask.
When polishing, if presenting a part to a bench mounted buffing unit, NEVER put a pinkie through a convenient hole, as this is a good way to lose a finger.
A hand drill might be OK for very small jobs, but difficult to control for anything else.
Small buffing wheels (mops) up to say 3 - 4 inches diameter - need to run at 3,000 RPM to generate some friction/heat- your bench grinder will only be doing approx. 1450 RPM, and the spindles are generally too short to allow manipulation of parts around the mops.
Buffing compounds are different according the type of metal you want to polish - you kit appears to have a grey and a white bar compound - read the instructions, but the grey one is almost certainly for first stage buffing, and the white one is for final buffing. Work up a 'head' of compound on the face of the wheel, and re-apply a little wipe with every few seconds of polishing. On soft metals - e.g.aluminium or brass - the wheel surface will adopt the colour of the metal being worked, which is telling you the process is functioning correctly.
Stainless steel is a tough cookie to polish!!
Before buffing, parts need to be abraded to remove scratches, dings etc., probably going down in stages to 120, 240 and 320 grit abrasive grain.
Rick
Re: Metal Polishing
The DIY kits are basic, I found that the mop's are pretty soft and will not last that long, I killed off an electric drill once years ago using mop's and wire wheels, as drills are not deigned for the sideways force.
I now have a large motor with a long pigtail and a sisal mop, I clamp it in my vice when I need to use it, I do the same with my grinding wheel, I have bench grinders, but with a small shed I never found a place to put one, as they don't get used that often.
Vienna Lime is handy to have, you use it to remove any polishing compound, it makes life much easer, also if you use a pigtails, it will eat soft cheap mops. If I cannot get into an area to polish I just get the 110V dremel out.
I now have a large motor with a long pigtail and a sisal mop, I clamp it in my vice when I need to use it, I do the same with my grinding wheel, I have bench grinders, but with a small shed I never found a place to put one, as they don't get used that often.
Vienna Lime is handy to have, you use it to remove any polishing compound, it makes life much easer, also if you use a pigtails, it will eat soft cheap mops. If I cannot get into an area to polish I just get the 110V dremel out.
Re: Metal Polishing
Wow, fantastic advice. Thanks guys. Good info re drill, Keith and Vienna Lime. How does the pig tail work.... push fit for mops??
Rick, great advice from a professional again. I'll have a play with what I've got and then decide if I'll get a polishing machine. Found this on ebay. http://www.ebay.com.au/itm/200mm-560w-B ... SwPYZU9C-d and this http://www.ebay.com.au/itm/Variable-Spe ... SwOtdYUT20 though 200 watt sounds a bit low. If we wish for 3000rpm that will be spinning the outside of the 3 inch mop pretty quick. Using a drill with a lot smaller circumference will reduce the outside mop speed a lot more than half
Thanks for the grit grades. Can they be machine done or wet&dry by hand? Is the extractor fan for health, mess or contaminating the finish? Gloves, mask and glasses sound mandatory.
Adrian, I never did buy the bonny. Still collecting dust so not sold yet.
Rick, great advice from a professional again. I'll have a play with what I've got and then decide if I'll get a polishing machine. Found this on ebay. http://www.ebay.com.au/itm/200mm-560w-B ... SwPYZU9C-d and this http://www.ebay.com.au/itm/Variable-Spe ... SwOtdYUT20 though 200 watt sounds a bit low. If we wish for 3000rpm that will be spinning the outside of the 3 inch mop pretty quick. Using a drill with a lot smaller circumference will reduce the outside mop speed a lot more than half
Thanks for the grit grades. Can they be machine done or wet&dry by hand? Is the extractor fan for health, mess or contaminating the finish? Gloves, mask and glasses sound mandatory.Adrian, I never did buy the bonny. Still collecting dust so not sold yet.
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tambikeboy
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Re: Metal Polishing
The old elbow grease comes to mind a roll up hanging of the lip willie nelson on the wireless a tub of autosol and the relaxation class begins...
Roll me up and smoke me when I die
Regret is just a memory written on my brow
Regret is just a memory written on my brow
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tambikeboy
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Re: Metal Polishing
That machine wouldn't last 5minsHugz wrote:Wow, fantastic advice. Thanks guys. Good info re drill, Keith and Vienna Lime. How does the pig tail work.... push fit for mops??
Rick, great advice from a professional again. I'll have a play with what I've got and then decide if I'll get a polishing machine. Found this on ebay. http://www.ebay.com.au/itm/200mm-560w-B ... SwPYZU9C-d and this http://www.ebay.com.au/itm/Variable-Spe ... SwOtdYUT20 though 200 watt sounds a bit low. If we wish for 3000rpm that will be spinning the outside of the 3 inch mop pretty quick. Using a drill with a lot smaller circumference will reduce the outside mop speed a lot more than half
Adrian, I never did buy the bonny. Still collecting dust so not sold yet.
Roll me up and smoke me when I die
Regret is just a memory written on my brow
Regret is just a memory written on my brow
Re: Metal Polishing
It used to be possible to buy a foot mounted electric motor 2HP (0.75Kw) 3000 RPM from outlets such as Machine Mart, if you have similar equivalents in Oz. Next step is to find little jobbing machining company who can make you a taper spindle (pig tail) to fit the motor spindle, where the O.D. will start around one inch, running down to nothing - this has to be 'handed' depending on which was the motor runs - basically, the mop or buff winds itself onto the taper and locks on - easily released by a smart rap with the hand (with the motor off obviously) in the opposite direction to the running direction.
The correct angle of the taper is important (which I can't remember now!)
It is possible to buy old buffing machines here, but they are very bulky for home workshops for occasional use, and are nearly all three phase motors, where houses are all single phase supply.
They are typically twin spindle ( a spindle out of each end of the motor), and to get real fancy, one end can be for the buffs, and the other end rigged up to accept linishing belts to do the abrasive work. Simpler solutions for abrasives can be abrasive flap wheels or discs, or good old hand power behind emery cloth!
You may find industrial suppliers of buffing machines which use tapered spindles, which is the accepted method for mounting mops, either to buy a spindle from as a spare part, or as a source of inspiration.
The mops produce a fine dust, which coupled with the buffing compound goes everywhere. probably not noticeable on a small job, hence some form of exhaust is highly desirable, predominantly for health and controlling mess, and yes - gloves, glasses and mask all good.
On Keiths' photo you can make out a taper spindle on a motor, but the taper looks to be a very low angle.
The sisal mop he mentions is a dense string weave, normally used for coarse buffing on ferrous materials - all buffs for non-ferrous materials are normally all cotton disc based.
Rick
The correct angle of the taper is important (which I can't remember now!)
It is possible to buy old buffing machines here, but they are very bulky for home workshops for occasional use, and are nearly all three phase motors, where houses are all single phase supply.
They are typically twin spindle ( a spindle out of each end of the motor), and to get real fancy, one end can be for the buffs, and the other end rigged up to accept linishing belts to do the abrasive work. Simpler solutions for abrasives can be abrasive flap wheels or discs, or good old hand power behind emery cloth!
You may find industrial suppliers of buffing machines which use tapered spindles, which is the accepted method for mounting mops, either to buy a spindle from as a spare part, or as a source of inspiration.
The mops produce a fine dust, which coupled with the buffing compound goes everywhere. probably not noticeable on a small job, hence some form of exhaust is highly desirable, predominantly for health and controlling mess, and yes - gloves, glasses and mask all good.
On Keiths' photo you can make out a taper spindle on a motor, but the taper looks to be a very low angle.
The sisal mop he mentions is a dense string weave, normally used for coarse buffing on ferrous materials - all buffs for non-ferrous materials are normally all cotton disc based.
Rick
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Collector Inspector
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Re: Metal Polishing
Polishing........a chestnut of a topic.Hugz wrote:Thought I'll do a bit of research on metal polishing and gain some advice. Bought this cheapo kit to get me started before progressing to buffing on a bench grinder. What techniques can you guys advise me about?
polishing kit.jpg
Going for a mirror result I. personally have never been keen on.
As I always have said polishing by hand using no power tools whatsoever is truly something that floats my boat..............however I am always interested in "Others" ways and means.
Interesting topic and watching aye!
BnC
A chicken is one egg's way of becoming others
Re: Metal Polishing
Tend to agree Bruce - I don't like going above and beyond original finishes generally, however I have more or less finished an Anzani Minor which has a cast aluminium tank and 'elves hat' cover which were polished originally, and had acquired some battle scars over the years - still not perfect by any means, as I don't have a proper buffing setup long since, but with a bit of attention looks a whole lot better than it did.
By the way, I should have picked up on Keith's comments that hand drills really don't like side loads - possibly OK for light sanding operations, but not for the pressures necessary for buffing.
Rick
By the way, I should have picked up on Keith's comments that hand drills really don't like side loads - possibly OK for light sanding operations, but not for the pressures necessary for buffing.
Rick
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headdownarseup
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Re: Metal Polishing
Call me OLD SKOOL if you like, but i prefer good 'ol fashioned elbow grease. (i've got so used to wearing away my fingertips by now it's become second nature)
Emery paper and wet/dry sandpaper for the various stages of the clean-up and dressing,maybe some steel wool as well, then move to a proprietary metal polish (solvol autosol is a good one, so is autoglym metal polish (my personal favourite) but there are many) and as much time as you want to give the work piece before your arms turn to jelly. Dremel tools come in handy for those "hard to reach areas" and so will a powerdrill but use it sparingly of course.
I'm with Rick and Bruce on this.
I've never really liked the super high "bling finish" (although it depends on what it is) but for example on a seagull gearbox i actually like to see a few battle scars. Keeps things honest looking, and probably more in keeping with how a seagull perhaps should look like.
By hand (and i'm not bragging with this either) i can do a flywheel from start to finish in just over 1 hour. A 102 gearbox in around 4 hours (depending on how badly its scratched and dinged) and all with basic hand tools, nothing fancy just good 'ol fashioned elbow grease.
oh, and i work inside a 10x8 shed with no heating and not much space for bench mounted power tools either, but even so i still achieve good results like this.
Each to their own
Jon
Emery paper and wet/dry sandpaper for the various stages of the clean-up and dressing,maybe some steel wool as well, then move to a proprietary metal polish (solvol autosol is a good one, so is autoglym metal polish (my personal favourite) but there are many) and as much time as you want to give the work piece before your arms turn to jelly. Dremel tools come in handy for those "hard to reach areas" and so will a powerdrill but use it sparingly of course.
I'm with Rick and Bruce on this.
I've never really liked the super high "bling finish" (although it depends on what it is) but for example on a seagull gearbox i actually like to see a few battle scars. Keeps things honest looking, and probably more in keeping with how a seagull perhaps should look like.
By hand (and i'm not bragging with this either) i can do a flywheel from start to finish in just over 1 hour. A 102 gearbox in around 4 hours (depending on how badly its scratched and dinged) and all with basic hand tools, nothing fancy just good 'ol fashioned elbow grease.
oh, and i work inside a 10x8 shed with no heating and not much space for bench mounted power tools either, but even so i still achieve good results like this.
Each to their own
Jon
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Charles uk
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Re: Metal Polishing
Rick doesn't explain his credentials in this area, he was technical sales for Cannings, & spent all of his working life in the metal finishing arena!
Cannings were the foremost supplier of metal finishing/polishing equipment & compounds, & there is a strong possibility that they supplied the equipment that Seagull used to polish all their early props & lower units.
If I had a question in this area, he's the man I'd call, as he knows what he's talking about & isn't just guessing!
Cannings were the foremost supplier of metal finishing/polishing equipment & compounds, & there is a strong possibility that they supplied the equipment that Seagull used to polish all their early props & lower units.
If I had a question in this area, he's the man I'd call, as he knows what he's talking about & isn't just guessing!
Make it idiot proof and someone will make a better idiot.
Re: Metal Polishing
Well most vintage seagulls were polished from the factory, so what's wrong in repolishing them again.
If it was painted, then repaint it, if it was polished then repolish it, its called RESTORATION.
When you get a motor with 20 years of lacquer burnt into the brass exhaust, you need a polisher.
Copper or brass that has been heated and cooled repeatedly is much harder to polish and sometimes impossible by hand.
If it was painted, then repaint it, if it was polished then repolish it, its called RESTORATION.
When you get a motor with 20 years of lacquer burnt into the brass exhaust, you need a polisher.
Copper or brass that has been heated and cooled repeatedly is much harder to polish and sometimes impossible by hand.
Re: Metal Polishing
Yes heated varnish that has turned to carbon on a brass exhaust.. that takes some getting off for sure. Starts with emery cloth and slowly work back through the finer wet and dry before polishing.
My pet hate is to see a engine that has been flashed over without stripping.. silver hammerite smooth, bolts heads and all.. Its horrible!
My pet hate is to see a engine that has been flashed over without stripping.. silver hammerite smooth, bolts heads and all.. Its horrible!
Re: Metal Polishing
Silver paint on a seagull, never done it, I have never restored a late seagull.
Just remembered I restored a TC, bum.
This will upset someone then.
Before.
After.
Too much bling?
Just remembered I restored a TC, bum.
This will upset someone then.
Before.
After.
Too much bling?