I’ve already had a few questions about polishing – so I thought this might make a useful post. We’ve all seen countless tune videos that involve polishing parts in an airgun to make them work better and smoother. The trouble is, in half the videos, the result is good, but the polish on the parts is not as good as it could be, therefore limiting the tune of the gun.
In metal to metal contact – smoothness is king.
NMShooter will attest – in dental school you learn how to polish every kind of material from metal to ceramic and zirconia. Here’s the key – It’s all about making progressively smaller scratches until you can’t see the scratches anymore.
Think about Sanding wood – you go from 80 grit (very course) to 1000-1200 grit (extremely fine). You go in that order so that you continually get the scratches smaller and smaller until they are imperceptible.
Metal is the same way – you just need to know what you are polishing and what you are polishing with. It goes without explanation that in order to scratch something, you have to have something that is harder that the thing you are scratching. Think glass and diamonds – the diamonds scratch the glass, but the glass won’t even leave a mark on the diamond… that’s because it’s not as hard. If you think about the metals predominant in airguns- aluminum, brass, and steel – aluminum is the softest, brass the next, and the hardest is steel. So if your part you need to polish is the hammer in your airgun and it's made of steel – you'll need more abrasive polishers to work with... likewise you'll need less abrasive polishers for brass and aluminum.
You can do almost all the polishing with a Dremel/Rotary tool and a Harbor Freight “rotary tool accessory set.”
https://www.harborfreight.com/276-pc-rotary-tool-accessory-set-62440.html
If you want the diamond impregnated rubber polishers like I'll use here you can get some from amazon:
https://www.amazon.com/PHYHOO-Jewelry-Polishing-Diamond-rubber/dp/B01B76D9FS/ref=pd_sim_469_3?_encoding=UTF8&pd_rd_i=B01B76D9FS&pd_rd_r=8d1adc2e-fa52-11e8-84c9-c9e00b2a0326&pd_rd_w=1dUOM&pd_rd_wg=B8GSi&pf_rd_p=18bb0b78-4200-49b9-ac91-f141d61a1780&pf_rd_r=YGNWBJ66KFYRA24N2TNQ&psc=1&refRID=YGNWBJ66KFYRA24N2TNQ
If you want the best shine possible, you can get Bar Buffing (or Tripoli) compound and Red Rouge – This kit from amazon is perfect and includes both. You can use these with a horse hair bristle brush or a rag wheel – either on a Dremel or a lathe depending on the size part you are working with.
https://www.amazon.com/dp/B079Y5CPR2/ref=sxbs_sxwds-stvpv2_3?pf_rd_p=6375e697-f226-4dbd-a63a-5ec697811ee1&pd_rd_wg=yd9p8&pf_rd_r=5W8MW4RGJKEXNAQKFPC4&pd_rd_i=B079Y5CPR2&pd_rd_w=f1wR3&pd_rd_r=f83d9148-9e70-495f-babd-f50093835a5c&ie=UTF8&qid=1544208698&sr=3
Always polish the part in the direction the part is used - like in the example of the hammer - you would polish so that the scratches would be longitudinal - or long ways down the long axis of the cylinder.
Start with the most abrasive rubber impregnated wheel or cylinder you have at a slow speed working toward the least abrasive – spend the most time with this tool getting all of the deeper scratches out – but you have to be careful, the more abrasive the polisher and the harder you push, the more metal it cuts away. Take care not to change the shape of the part you are working on, only remove the scratches. This is where the Kit from Harbor freight/Amazon comes in. The rubber impregnated polishers work great for this. Also - here's a trick to avoid changing the shape of the part - notice how I'm holding the Dremel with a thumb rest on the part - that gives you the most stable base possible rather than holding the Dremel like a pencil.
PS: You'll want to wear safety glasses with these things - the can fly apart and hit you right in the eye... ask me how I know.
I polished half of this steel slip ring from my bipod to show how the abrasive rubber wheel can cut away metal and smooth out the ridges left over from the milling process. If you need to completely remove manufacturing ridges like this, start with an abrasive stone to level and then move to the rubber impregnated polishers.
Once the part is somewhat smoothed, you can move to the bar buffing compound or Tripoli. This works best on a horsehair brush on either a Dremel for small parts or a lathe for large parts. This is what I used - you might be able to find the Jelenko brand BBC - it works the best on all metals from aluminum to steel, even gold and brass. One container will last you a lifetime - this one is 15 years old and has been used a ton.
Pick up the BBC on your brush by running the wheel and spinning it into the compound.
It will start our by coating the part in a black haze, then as you continue to polish, it will break down and the particles in the compound will become progressively smaller and polish away, leaving a pretty high shine.
Take your time with this stuff - the slower you go the better as the compound breaks down. This is what will give you the best smoothness and shine.
This is what aluminum looks like after the BBC step:
Here is steel, notice it's still scratched, but you have to look close to see it:
To clean the excess caked on polishing compound between abrasives Windex works perfectly.
The last step is Red Rouge – this can be applied with either a brush or a rag wheel. This is done quickly. Charge the brush or rag wheel with the rouge, you don't need a ton, just touch the bar quickly.
Then buff quickly and lightly and you will see the high shine develop.
I tried to take as close a photo as possible so show the very fine scratches still visible if you look closely - you can get rid of these by going back through the BBC step and the Rouge again... it this was a hammer or a trigger sear, that's what I'd do. But in this case, it's for a bipod and good enough.
Hope this helps... Doc
In metal to metal contact – smoothness is king.
NMShooter will attest – in dental school you learn how to polish every kind of material from metal to ceramic and zirconia. Here’s the key – It’s all about making progressively smaller scratches until you can’t see the scratches anymore.
Think about Sanding wood – you go from 80 grit (very course) to 1000-1200 grit (extremely fine). You go in that order so that you continually get the scratches smaller and smaller until they are imperceptible.
Metal is the same way – you just need to know what you are polishing and what you are polishing with. It goes without explanation that in order to scratch something, you have to have something that is harder that the thing you are scratching. Think glass and diamonds – the diamonds scratch the glass, but the glass won’t even leave a mark on the diamond… that’s because it’s not as hard. If you think about the metals predominant in airguns- aluminum, brass, and steel – aluminum is the softest, brass the next, and the hardest is steel. So if your part you need to polish is the hammer in your airgun and it's made of steel – you'll need more abrasive polishers to work with... likewise you'll need less abrasive polishers for brass and aluminum.
You can do almost all the polishing with a Dremel/Rotary tool and a Harbor Freight “rotary tool accessory set.”
https://www.harborfreight.com/276-pc-rotary-tool-accessory-set-62440.html
If you want the diamond impregnated rubber polishers like I'll use here you can get some from amazon:
https://www.amazon.com/PHYHOO-Jewelry-Polishing-Diamond-rubber/dp/B01B76D9FS/ref=pd_sim_469_3?_encoding=UTF8&pd_rd_i=B01B76D9FS&pd_rd_r=8d1adc2e-fa52-11e8-84c9-c9e00b2a0326&pd_rd_w=1dUOM&pd_rd_wg=B8GSi&pf_rd_p=18bb0b78-4200-49b9-ac91-f141d61a1780&pf_rd_r=YGNWBJ66KFYRA24N2TNQ&psc=1&refRID=YGNWBJ66KFYRA24N2TNQ
If you want the best shine possible, you can get Bar Buffing (or Tripoli) compound and Red Rouge – This kit from amazon is perfect and includes both. You can use these with a horse hair bristle brush or a rag wheel – either on a Dremel or a lathe depending on the size part you are working with.
https://www.amazon.com/dp/B079Y5CPR2/ref=sxbs_sxwds-stvpv2_3?pf_rd_p=6375e697-f226-4dbd-a63a-5ec697811ee1&pd_rd_wg=yd9p8&pf_rd_r=5W8MW4RGJKEXNAQKFPC4&pd_rd_i=B079Y5CPR2&pd_rd_w=f1wR3&pd_rd_r=f83d9148-9e70-495f-babd-f50093835a5c&ie=UTF8&qid=1544208698&sr=3
Always polish the part in the direction the part is used - like in the example of the hammer - you would polish so that the scratches would be longitudinal - or long ways down the long axis of the cylinder.
Start with the most abrasive rubber impregnated wheel or cylinder you have at a slow speed working toward the least abrasive – spend the most time with this tool getting all of the deeper scratches out – but you have to be careful, the more abrasive the polisher and the harder you push, the more metal it cuts away. Take care not to change the shape of the part you are working on, only remove the scratches. This is where the Kit from Harbor freight/Amazon comes in. The rubber impregnated polishers work great for this. Also - here's a trick to avoid changing the shape of the part - notice how I'm holding the Dremel with a thumb rest on the part - that gives you the most stable base possible rather than holding the Dremel like a pencil.
PS: You'll want to wear safety glasses with these things - the can fly apart and hit you right in the eye... ask me how I know.
I polished half of this steel slip ring from my bipod to show how the abrasive rubber wheel can cut away metal and smooth out the ridges left over from the milling process. If you need to completely remove manufacturing ridges like this, start with an abrasive stone to level and then move to the rubber impregnated polishers.
Once the part is somewhat smoothed, you can move to the bar buffing compound or Tripoli. This works best on a horsehair brush on either a Dremel for small parts or a lathe for large parts. This is what I used - you might be able to find the Jelenko brand BBC - it works the best on all metals from aluminum to steel, even gold and brass. One container will last you a lifetime - this one is 15 years old and has been used a ton.
Pick up the BBC on your brush by running the wheel and spinning it into the compound.
It will start our by coating the part in a black haze, then as you continue to polish, it will break down and the particles in the compound will become progressively smaller and polish away, leaving a pretty high shine.
Take your time with this stuff - the slower you go the better as the compound breaks down. This is what will give you the best smoothness and shine.
This is what aluminum looks like after the BBC step:
Here is steel, notice it's still scratched, but you have to look close to see it:
To clean the excess caked on polishing compound between abrasives Windex works perfectly.
The last step is Red Rouge – this can be applied with either a brush or a rag wheel. This is done quickly. Charge the brush or rag wheel with the rouge, you don't need a ton, just touch the bar quickly.
Then buff quickly and lightly and you will see the high shine develop.
I tried to take as close a photo as possible so show the very fine scratches still visible if you look closely - you can get rid of these by going back through the BBC step and the Rouge again... it this was a hammer or a trigger sear, that's what I'd do. But in this case, it's for a bipod and good enough.
Hope this helps... Doc