shimmystep
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Can't seem to get the mirror finish I want on this brass, it was horribly scratched up before started. I used the increasing grain with wet and dry going up to grit and am using Maas metal polish to finish, which I have found to superior to other metal polishes but can't get a finish without these very very feint marks. Thoughts anyone? TIA
Thyme
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Can't seem to get the mirror finish I want on this brass, it was horribly scratched up before started. I used the increasing grain with wet and dry going up to grit and am using Maas metal polish to finish, which I have found to superior to other metal polishes but can't get a finish without these very very feint marks. Thoughts anyone? TIA
I've never needed to do polishing that fine, but here are some references to point you in the right direction: click here.
The article mentions "When polishing brass, there are often minute marks in the metal caused by impurities. To overcome this, the surface is polished with a very fine (600) grit, copper plated, then buffed to a mirror finish with an airflow mop."
You might be able to do it by hand using polishing rouge. If you need to buy these buffing wheels (AKA 'mops') here is a link for them: click here.
shimmystep
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I've never needed to do polishing that fine, but here are some references to point you in the right direction: click here.
The article mentions "When polishing brass, there are often minute marks in the metal caused by impurities. To overcome this, the surface is polished with a very fine (600) grit, copper plated, then buffed to a mirror finish with an airflow mop."
You might be able to do it by hand using polishing rouge. If you need to buy these buffing wheels (AKA 'mops') here is a link for them: click here.
Thanks Thyme, I prefer to do this by hand so might try the rouge, though I understand it can be messy and leave a red tint, I imagine acetone will clean that tint off (?)
I expected my original staged build up to grit would have left a better finish to polish.
Thyme
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Thanks Thyme, I prefer to do this by hand so might try the rouge, though I understand it can be messy and leave a red tint, I imagine acetone will clean that tint off (?)
I expected my original staged build up to grit would have left a better finish to polish.
I thought it looked really good for most expectations, but you desire a highly polished surface.
You are in the UK. Here in the US I think our numeric rating standard for abrasives only goes up to . Beyond that, it must be done with compounds.
In this case, finer is better, and required. But doing fine polishing is labor intensive.
Talyinka
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There can be two reasons for getting residual marks after polishing: either you have impurities in the metal, or you have switched to a finer grain before
completely removing the marks from a coarser grain. The photo seems to indicate that the latter could be the case here - the marks seem to be arranged in circular patterns like those easily left by a polishing process. This type of polishing is the first they teach you when you need to prepare metal specimens for electron microscopy and it is not nearly as easy as it sounds.
shimmystep
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The marks you can see are left by the Mass polish, all the scratches from the previous stages were lost through straight cross rubbing horizontally and vertically and these marks are circular from the polish motion as you say Talyinka. It has been and always will be my belief that fine metal polishing is a dark art!
I'll use some rouge but you're probably right Thyme, to paraphrase you, 'I'm being too fussy'.
Thyme
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I'll use some rouge but you're probably right Thyme, to paraphrase you, 'I'm being too fussy'.
Well, you can be as fussy as you please. It's your choice!
If nothing else, it's an experiment in learning how to do something new.
Scottie-TX
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My experience has been that if at whatever stage of polishing or sanding that if the next, less agressive stage fails to remove the scratches left from the previous stage - then at least one of the previous stages was not sufficiently complete enough to prepare it for the next stage. My approach is to rub in different directions in each stage. That way I know in which stage of progress my process was not complete or sufficient to go to the next stage. In other words if you didn't sufficiently complete a stage at for example, then further sanding or polishing at let's say, or above will either be laborious or not even possible.
Talyinka
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100% correct procedure, Scottie. You rub in a different direction until you get a uniform-looking surface when viewed in light coming in at a low angle from opposite your viewing position. This indicates that the polishing pattern from the process step
before the current has been reduced in depth to the level of the current grain size. As a consequence continuing with the current sanding/polishing will produce no further improvement and you are ready to go to the next step.
It is important of course, to carry out this operation wet so that any tendency for carbides to congregate and cause scratches deeper than their grain size is curbed.
shimmystep
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My experience has been that if at whatever stage of polishing or sanding that if the next, less agressive stage fails to remove the scratches left from the previous stage - then at least one of the previous stages was not sufficiently complete enough to prepare it for the next stage. My approach is to rub in different directions in each stage. That way I know in which stage of progress my process was not complete or sufficient to go to the next stage. In other words if you didn't sufficiently complete a stage at for example, then further sanding or polishing at let's say, or above will either be laborious or not even possible.
Agree with you Scottie. As described I used this method patiently, there are nil vertical or horizontal scratches from the previous stages left so I'm satisfied that I have completed the process you describe effectively. The marks left are circular only and are from the final polishing action with Maas. I, apparently, need to ensure the scratches width are smaller than the frequency of visible light.
Scottie-TX
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I'm not familiar with MAAS. I've used SIMICHROME for many years. Could it be that MAAS is not fine enough to achieve the finish you seek? Also, auto paste wax can bring the luster up even further after metal polish.
Thyme
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I'm not familiar with MAAS. I've used SIMICHROME for many years. Could it be that MAAS is not fine enough to achieve the finish you seek? Also, auto paste wax can bring the luster up even further after metal polish.
Scottie,
If your recommendation works (and I'm not denying that it would for casual or ordinary purposes) that approach might fill in the fine scratches and make it shine.
However, since he desires a highly polished "mirror finish" (the initial proposition of this thread) I doubt that any wax can achieve it. I'm beginning to think that what he wants is not easily achieved with 'at home' methods.
Scottie-TX
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Well I'm not advocating or suggesting that any product can fill scratches. I doubt they can. My approach is to remove scratches and, "no", auto paste wax is only minimally capable of doing that as it's abrasive component is VERY minimal.
leeinv66
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What sort of polishing cloth are you using?
shimmystep
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Thanks for the input folks. Could be right re the fineness of the Maas Scottie, it's the finest polish I've tried to date.
I've been using a Selvyt cloth to polish on and off, however I've ordered an air mop for the wheel and some Menzerna yellow grade polishing compound, so that will be the 'line in the sand' as it were. I'll post the results when I get them.
Scottie-TX
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Interesting question Pee-Tah: When one gets down to this ultimate fineness of abrasive I've even considered as you have, how abrasive the cloth. I have actually used my hands to apply the final finish. No cloth! Just the polish on my hands. I cannot say tho that the results were any improvement over any cloth I've used.
Tony10Clocks
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Have you tried a clay bar, the sort you can get for polishing paint work. It's a bit expensive for an experiment, but if you know someone who has some you can borrow, might be worth a try, come to think of it i might have some in the shed
Jay Fortner
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Hand polishing will get it done EVENTUALLY but I have neither time nor patience for such an archaic method. I use a buffing machine with a range of wheels from 10" to 3"(normally worn down 10's) and from sisal to spiral sewn cotton to canton flannel.
Sisal is very aggresive and used when getting a rough casting down smooth normally I use a greaseless coumpound in the 200 and 320 range but you won't be needing any of that. Next is a spiral sewn cotton buff with white rouge,some use tripoli but I've found it useless as teets on a boar hog. Next is white rouge on a canton flannel buff and this is where you turn the RPM's down and reduce pressure,Oh she's getting shiny now. To get that mirror finish I use a step I call dry wheeling where I use a canton flannel buff,no compound,low revs and very light pressure. The most important step is to make sure you clean all traces of compound before this final stage.
Those yellow microfiber rags that look like synthetic flannel are the softest scratch free rags I've found yet,if you drop it on the floor,toss it,guaranteed it picked up abrasives. You can use any soft rag until that final wipe then only the yellow will do.
shimmystep
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Thanks fellas. I tried a soft loose mop wheel with yellow mirror finish compound but tbh wasn't impressed. I've been using exactly that microfibre cloth you mention Jay funnily enough, with Maas polish by hand with low pressure. A lot of effort but seems to pay off.
Jay Fortner
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Thanks fellas. I tried a soft loose mop wheel with yellow mirror finish compound but tbh wasn't impressed. I've been using exactly that microfibre cloth you mention Jay funnily enough, with Maas polish by hand with low pressure. A lot of effort but seems to pay off.
Once you think you've got it shiny using your compound clean your workpiece of all traces of compound the rub-rub-rub with a new clean rag. This is a Stainless radiator shell that I made for a kit car. The metal started out with a brushed finish. I had to use sisal with 220 then 320 then spiral sewn and emery then spiral sewn and white rouge then loose section and white rouge then canton flannel and white rouge then dry canton flannel. If I remember it was four days with a machine. The guy was towing it back to Maine,stopped to get gas and relief and when he came out some thieves were trying to unhook the trailer from his truck. He called the cops and they split.
David S
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Very nice work Jay. Not sure I would have the patience today.
Jay Fortner
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Very nice work Jay. Not sure I would have the patience today.
Probably not me either.