Want a really nice finish for your metal tracks but paint isn't tough enough and you don't want to chance the vinegar trick? Try a gun blue! The finish is hard, has a nice texture and a great color! Best of all you can use the tracks right away! The process is very fast. From start to finish you can have a finished set of tracks in just a few hours! The actual labor time I would estimate at 30 minutes or less!

I was asked about bluing in my build thread so I thought to put the tip here as well.
The blue is a firearms related product. It's a common way of finishing the metal surface of guns. The blue is a chemical acidic liquid that rusts the surface of a gun in a helpful way. There are at least three kids of acid in the compound mixture. Any ferrous metals can be blued except for aluminum and stainless steel, perhaps more but I do not know. You get the idea, that any metal that easily rusts can be blued.
On raw metal the bluing will literally, before your eyes almost instantly rust the surface of the metal it contacts with. The rust is black and hard, not typical soft brown flakes. It's not how you think of ordinary rust and actually can be helpful in protecting the metal. Liquid blue comes in different formula for different color finishes. If you don't like the black/grey there are other colors.
Here is the product I chose. Birchwood Casey Super Blue. It has been used by others who have done this to metal tracks as well with great result.
That little 3 oz would be enough for a small firearm like a handgun, or some touch up. For the tracks I used every drop! There is a lot of surface area for a set of tracks! You might want to get a little extra if planning to do this so you don't run out in the middle of doing it.
A warning!!!! The blue is very, very dangerous. You must wear gloves when working with it, like rubber surgical gloves and definitely wear eye protection! The acid can stain, or hurt your skin after exposure, can cause blindness in eyes and can be fatal if even a small amount is ingested! If you like, wear a mask too to avoid splashes in mouth or nose. Also, the blue has very little odor.
The process follows...
1. Take your item to be blued and thoroughly wash it with soapy water. Remove any dust, grease, fingerprints, or anything else that could interfere with the bluing. Do this with clean hands so you do not transfer anything to the item while handling it.
2. Rinse the item with water and make sure all soap and residue is removed!
3. Set up your work area. I used my very large kitchen sink, stainless steel so it wouldn't get damaged by the blue. Put on safety gear before opening the blue! Using a bowl, dish or other container pour a small amount of blue in it and place the container in the sink. I used a large glass bowl big enough to fit the track in. I also cleaned an old toothbrush with soap for the project. Also, put an old rag, or paper towels down for the tracks to dry on once the bluing is done.
4. Once set-up I then used the toothbrush and dipped the brush in the liquid blue and rubbed the brush's bristles onto the surface I was bluing. Don't worry about water on the tracks, it had no bad effect on the process. The blue liquid is very thin like water and should flow into all the cracks but be sure to get every little inch of the track covered in blue. You should see the track changing color rapidly to know the process is working. Keep on getting the blue on the track where it needs it and go all over. You don't need to rub hard, just make sure you get every area you can.
5. It shouldn't take more than 10-15 minutes per track, that might be pushing it! Don't make multiple passes unless you need to get a spot you missed as you can even rub off the nice new surface you've given the metal. Once the entire track is done, or you need to stop for some reason, wash off the track with cold water immediately! I was actually rinsing mine, and then submerging it and shaking it under the water to make sure every bit of the blue was gone. Rinse multiple times! Once you are certain it is rinsed well take the track, shake off excess water if you like and place it on the rag/towel to dry. It might take awhile to fully dry. If handled you might rub off some the the finish onto your hands so be patient.
6. When dry, inspect, and enjoy your new tracks! Paint, weather, or do with as you like now!
I have not personally run my tracks yet but it's been said that the blue can wear off in well uses spots. This would further the finish as the silver tracks would show in worn spots making the tracks appear to be like real tank tracks even more! Get them dirty and worn a bit and you have some authentic tank tracks for your model! For a static model I might still recommend paint over blue.
Other tankers than have done this too! Thanks to these builders for sharing the process publicly!
http://www.rctankhq.com/project1.htm
http://www.rctankregiment.com/rctankfor ... hp?p=25565
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