Hi guys, While I'm waiting for a couple of parts to arrive I've turned my attention to polishing the tank. Below is a picture of the tank with polishing in progress and then a picture of the lantern before any work done for reference. This is a brass tank with nickel or chrome plating. My concern is that I've seen a couple of small areas where either through my own polishing or through previous owner polishing or wear there is some brass showing through. You can't really see it in the pictures and it is only a couple of tiny areas. I have been using polishing wheels for soft metal on a bench grinder and working from the base upwards as you can see in the pic, so the bottom part is in progress, the top part of the tank is untouched. Should I keep on going the same way? Or retreat from the bench grinder and go to a vinegar or acid solution? If so, what would you recommend? Thanks in advance. Polishing in progress: And here is the lantern before work started, noting that the colour in the photograph hasn't really come through right - the colour in the above photo is more like real life:
The tank is nickel plated brass and from what I have been told (I am no chemist), once nickel has aged it is not possible to get a mirror shine anymore. I make do with a citric acid bath and a polish with Autosol (or equivalent) if I'm feeling energetic.
If the nickel is already thin I would stay away from the polishing wheel. Citric acid (lemon juice ) applied with toothbrush and Autosol is what I use
@Pauly @Nils Stephenson and @ROBBO55 provide good advice. The nickel plating on these tanks can be quite thin after all these years, so cleaning first with future acid, then with Autosol, by hand, is the way to go. Because I’ve got a few projects on the go at the moment, I’ve made a batch of “GSR” - a mix of citric acid and wall paper glue formulated by a colleague at “Classic Camp Stoves”. It’s great for cleaning brass and nickel plate. The recipe can be found in this thread: Stove restoration. Parts 1 to 4 Cheers Tony
Thanks for pointing me in the right direction guys. Glad I asked instead of persisting with the bench grinder. I could give it a go with this. If so do you reckon the mix for descaling kettles on the back of the container would be about right for what I am doing - 25g to the litre? Front: Back:
You can also use vinegar, Coke (the drink, NOT the white powder!) or other fizzy drinks such as Kool-Aid (whatever that is!). These contain various organic acids - acetic acid in the case of vinegar, which is cheap but smelly. I'm not sure of the formula for Coke but it probably contains formic or phosphoric acids or similar - yuk! The key thing to remember here is that lanterns weren't designed to last much longer than maybe 10-15 years and were constructed accordingly. Thus they're all living on borrowed time and were never meant to be cleaned with acidic solutions. So my advice would be to start very dilute (if Tony's solution/dilution works for him, I'd go with that) and for short periods only - maybe 20-30 minutes to start with. Overnight is usually too long. One thing I've found useful is to rinse the article after the first soak and 'work' off the dirt with my fingers and thumbs. It's amazing what comes off when I do that. If necessary, repeat the soaking. One thing to beware. If it's a brass tank, soaking in too strong a solution for too long will make it go pink - zinc is leached preferentially from the brass leaving a thin layer of copper on the surface. It's a bugger to have to polish that off. Don't ask me how I know...
Spent some time on this this afternoon. I had a look at the GSR recipe as I figured given the tank is worn through to brass in a couple of minor areas I don't want to make those areas worse, so using a paste rather than a liquid citric solution would be better. I didn't have any wallpaper adhesive and when asking my wife if she wanted anything from bunnings and that I was making a special trip she said "why not try cornflour?". She has made home-made glue for paper mache before using cornflour. It makes a glue similar in appearance to "clag". So I thought, good idea, I could mix in some citric acid powder. I thought I'd try first on the metho dish which was heavily corroded. Here are the pics. Metho dish before starting (but after a couple of days moving about with other brass bits and pieces in the brass tumbler using corn cob media which didn't really do anything to this type of metal): And here is a picture of the cornflour acid glue mix: Metho dish part way through treatment: And here is where I go to. I think from here I'm happy enough with it. This took about an hour of treatment. Toothbrush every five minutes or so and complete rinse and reapplication about two times - it doesn't look brand new but I think I'll go to Autosol with this piece now rather than risk too much wear:
So I have finally got some spare time to go back to the lantern. I did the citric treatment on the tank. Being careful over about a two hour period using the paste and toothbrush. I thought I'd be able to get a better finish but it has got to the point where I can see little spots of brass under what were the more heavily oxidised spots around the top of the tank. I think I'm just going to cut my losses here and go to autosol and accept it is a fairly weathered old lantern. If I happen to get another Austramax like this in similar condition I think I'll leave the patina as is. The new parts I need to get this up and running should arrive in the next day or two so that will be exciting to see one of these lanterns up and running in real life :-) Here it is. The container beside it contains the other bits and pieces that I'd had through the brass tumbler with corn cob media (I have this sitting around for another hobby), and then I've done a quick citric solution bath approx 20 minutes on the parts that didn't come up quite nicely enough, 1 tablespoon citric powder to 1 litre water.
It seems I was prematurely disappointed with where I ended up after citric treatment. Got some time again tonight and here is where it got to after some more light targeted work on the medium polishing wheel, a complete going over with the fluffy polishing wheel, and then a hand polish with autosol. Not mirror finish but I'm happy that it looks way better than when I first got it I retract my previous comment in this thread that I'd leave the original patina. That's it for me for tonight - back into the box for this stuff - next step when I can get some time again is on the tank - a quick internal flush with kero to get rid of any nasty bits before I move on to finishing cleaning the other disassembled parts. Very happy with the result tonight !
