Polishing Guide For Metals
Quick Guide to Polishing Metals
POLISHING METALSThe list below and general polishing processes that are proven to work, there are other compound and mop combinations that work just as well.
There are many factors involved in polishing some are listed below:
A) Condition of the metal with determining where you start.
B) Speed the mops runs at.
C) Quality of the metal. It does vary and bad casting can cause problems.
D) Abrasives, get a good even surface with no deep scratches to ensure a deep mirror finish.
E) Make sure you remove the marks left from a previous process
F) If possible try to alter the direction of the polishing for each process, even if only by a few degrees.
G) Do not overload polishing mops with compound. You will deposit grease on the work surface.
H) Use safety equipment, glasses and a dust mask. Dust is never nice. Polish outdoors if you have no extraction.
I) Vienna Lime can be used after polishing to remove light grease and finger marks etc. If the work needs degreasing then a solvent like white spirit works well. J) If the mop becomes clogged or dirty after use has been left on the shelf for a long time for example then use a mop dresser or wheel rake to bring new life into the mop. Never wash mops in water.
K) Use one compound per mop. This keeps everything simple for example if you are using a sisal mop with a grey compound try not to change. It is possible to change the compound but make sure the old compound has been removed. Tools like mop dressers and wheel rakes are ideal for this application.
L) Avoid imported DIY compounds such as Silverline, there are many brands such as Menzerna/Osborn/Dialux that have been selling high-quality polishes for over 75 years. Used by professionals.
M) Machine power, in general 150watt machine 4" wheels, 370 Watt 6"x1" wheels, 550watt 8"x1" wheels are available as converted bench grinders. More powerful machines 1hp 8"x1" max, 2HP 10"x1" max, 3HP 10"x2" max, 5HP 12"x2".
O) Work in stages One compound per mop. Each process is a different grade so it's important to make sure to keep each process separate.
P) Raking mops, two reasons. On flat surfaces you will pick small amounts of metal onto the polishing mop, this will cause micro scratching. Another reason when you polish now and then compound on hard mop hardens off, quick rake exposes the cloth and dab of the compound we are ready to go (we see a lot of this on plastics and resin polishing)
If the metal is in a poor condition then abrasives will be needed. That's where the experience of polishing comes in, looking at then metal and knowing what process you need to start at. You will need to get the surface to 240/400 grit before you start polishing at process 1. If the condition of metal is not too bad or you have the surface to 600 grit + then you could start at process 2.
Process 1 (Burnishing) Grey 523LBZ compound with a sisal polishing mop
Process 2 (Prepolishing) Green 439T compound with a white close stitched polishing mop
Process 3 (Polishing) Blue P164 Compound or White 495P Compound with a Loose G quality mop
Process 4 (Finishing) P175 for super finishing with a Loose WDR quality mop
Polishing Aluminium
Not as hard as the above metals, steel etc. When polishing aluminium if you are getting small holes that appear when you are polishing, stop. These can not be polished out they are due to the casting and if you keep polishing you will get more holes to appear. Best just buff up if this happens for damage limitation.
If the metal is in a poor condition then abrasives will be needed. That's where the experience of polishing comes in, looking at the metal and knowing what process you need to start at.
You will need to get the surface to 240/400 grit before you start polishing at process 1.
If the condition of the metal is not too bad or you have the surface to 600 grit + then you could start at process 2.
Some people prefer to use the green compound on Process 1 with a sisal rather than the grey.
There are a couple of options on finishing, P126 Rose is a superb finisher but for that extra special job P175 can be used.
Important For thin sheet Aluminium we have a new fine finishing compound available 480F, this is a light green compound that is more greasy than the normal finishing compounds which keeps the surface cooler. We avoid sisals on sheet work aluminium and look at soft wheels such as open stitch.
Process 1 (Burnishing) Green 439T compound with a sisal polishing mop
Process 2 (Prepolishing) Green 439T compound with a white close stitched polishing mop
Process 3 (Polishing) Blue P164 Compound or Blue 480BLF (compound formulated for aluminium) with a Loose G quality
Process 4 (Finishing) P175 for super finishing with a Loose WDR quality mop
Polishing Brass & Copper
Would say softer than the above metals but some grades of brass can be very hard. For example towel rails, in this case use the same process as steel above. If the metal is in a poor condition then abrasives will be needed. That's where the experience of polishing comes in, looking at then metal and knowing what process you need to start at. You will need to get the surface to 240/400 grit before you start polishing at process 1. Some people might want to use a brown Tripoli instead of green. For finishing both compounds are very good but for the extra special job use the P175. But P164 for general finishing, 480W works well as it is a compound designed for Brass and Copper only.
Process 1 (Prepolishing) Green 439Tor Tripoli 113GZ compound with a white close stitched polishing mop
Process 2 (Polishing) Blue P164 Compound or White 480W Compound with a Loose G quality
Process 3 (Super Finishing) P175 Compound with a Loose WDR quality mop
Polishing Gold & Silver
Common two processes used by the jewellers for years. There are some options on process 2, some people prefer to use a WDR or R grade mop.
Rouge has always commonly been used but compounds like the M5 and P175 are a decent alternative. If you are after a clear mirror finish then P175 if worth looking at.
Process 1 (Polishing) Brown Tripoli Compound with a Loose B quality mop
Process 2 (Finishing) Rouge Compound/P175 with a G quality or WDR mop.
Platinum Precious expensive metal. Harder than gold or silver.
Process 1 (Polishing) Blue P164 compound with a Loose B or white stitch mop
Process 2 (Finishing) Yellow P175 compound with a Loose G or WDR mop
Satin Finishing. Still have to remove major surface imperfections and scratches etc. Excellent at blending in jobs.
Available in four grades. Important!! to remember that each grade contains a grit but they do not have to cut or finish of a true abrasive, they give a much softer finish. The web on the VFA and FA looks almost exactly the same but as you can see the grits are very different. Very Fine A- 280 grit Fine A -180 grit Medium A - 120 grit Coarse A - 80 grit For flat work use Solid satin wheels for general work use satin lap mops. Check the abrasive section top product section. Both are for taper spindles but the Solid wheels can but made to fit a bore.
