Acid cleaning of Brass

[AUSDOK]

Hi I am cleaning up some brass fittings and have been using a formula for blow torches. The brass has taken on a pinkish hue. and needs to be cleaned. I have seen someone using a acid to clean brass and am unsure what type of acid and what concentration is used. Any info would be appreciated .Thanks Rudy

[steeleye]

Gday Rudy. The pinkish hue is normal.Now its time for the elbow grease and Brasso.....Phil

[rustyengines]

Hi Steeley
            Using acid to clean brass is not that easy it all depends on how much copper there is in the brass, you will find that blow torch brass and brass fittings are a different mixture of metals
The best way as Phil said 'elbow grease and Brasso' or what I do is a buffing wheel fitted to a grinder
Ian 

[tanksmate]

Hi Ian,  time to get some pollishing rouge from the local electroplaters mate and use that on the  pollishing wheel you have on the grinder or whatever, red colour for a rough pollish, white'(if you can get it ) for the finnish polish.
cheers  John 

[tanksmate]

sorry  RUDY  I should have addressed that to you not Ian,  cheers  John

[grumdum]

  Hello Rudy
             To clean brass and copper i use a quick dip into about half strength Nitric acid it works very quickly usually about 2/3 minutes then rinse very well in water  to kill the acid you can then buff to get the final polish then rub with brasso dry the job then coat with a clear coating,i find that this way the polish lasts 10 to 15 years with no loss of polish.
      Happy Rubbing
        Graham

[AUSDOK]

Thanks for the replies,where is the best place to get nitric acid from ? Rudy

[oldcranker]

'day Rudy, I just use hydrocloric, paint it on then under the tap, don't let it dry.
Try a bit of your bakers soldering fluid, it is probably milder.

[brnmrtin]

A mixture of salt and white vinegar will clean most old corrosion and verdigrease from brass and leave it ready for the finishing processes according to need. Grinding, polishing, and buffing or "colouring" are the three steps in metal finishing. Grinding to remove major imperfections, deep scratches, casting flash, etc., polishing to remove minor scratches, and buffing to bring up the desired high smooth finish. Different wheels and compounds apply to each step.

[grumdum]

  Hello Rudy
           Acids are available from chemical supply firms if you check your local yellow pages you should have no problem ,either under chemical supplies or industrial chemical supplies,unfortunately there is usually a minimum amout you can buy,at  the place i bought mine it was a 5 litre container ,i shared this with a couple of other cast iron maniacs.
             Happy Searching
                 Graham

[Teddy]

Hey all
While salt and vinegar are readsily obtainable, my missus tells me that bicarbonate of soda and vinegar does a better job. Wet the job with vinegar, sprinkle the bicarb. over it and scrub it off while it fizzes. Less dangeraous than the acid treatment.

What are blokes using to hold the shine? Grumdrum(Graham) says he coats the job with a clear finish- what do you use mate? Please?

Thanks to Rudy for starting the thread- it's something I've been going to ask for a while now (and didn't get around to.)

Thanks to all helpers
Teddy.

[Russell]

 Hi All
 I use citric acid the stuff used in baking  I use 1.5 teaspones to 1 lt off water leave parts in for about 2 hr wash them of then use brasso to finsh off . This is very safe to use dose not burn or harm the brass if you forget it . To seal the finshed part I use wattyl clear lacquer for copper & brass in a spray can . the citric acid also works on rusty metal have to mix it stronger used it on an engine that was sezed left for 1 week then had no trouble getting piston out hope this helps
 Russell

[AUSDOK]

Hi in the latest Tomm in the identity section on page11 there is some brass cleaned with electrolysis . I was unaware that this could be done, it looks pretty good. I have emailed Devon and await his reply. If this is possible with no damage it would be a useful addition to our cleaning kit. Thanks Rudy

[grumdum]

   Hello Rudy
             The clear coating that i use is Wattle INCRALAC available in spray pack or 5 litre cans,regarding the acid bath this  is a quick (about 2/3 minutes) way but if i have time i use the electrolosis bath ,i put everything that is metal through it brass copper cast iron steel die cast alloy etc, ,my current bath is 5 to 6 years old does a fantastic job and
whats more it works while you sleep,very cheap to run and works 24 hours a day 7 days per week you can leave the part to be cleaned in the bath as long as you like ,the bath i use is an alkali one and does not remove any metal from the job ,i have left jobs in the bath for extended periods of up to 3 months ( i forgot about them).You can now see that there is more than one way to kill a cat or remove oxidised coating.
         Enjoy Yourself
            Graham

[rustyengines]

             electrolosis bath ,cast alloy ,alkali one
Hi Graham
        I also have an electrolysis bath for many years and works very well
I use washing soda in my bath BUT the one thing i can't put in is alloy, I have put in a lawn mower base (alloy) but have to take it out after about 2/3 hrs all clean and you find the surface has been etched
Once I put an engine in with a alloy piston for 3/4 days before removing only to find the piston had been very badly eaten away
All other metals I put in are ok no matter how long they have been in the bath
So what do you put in your bath that does not effect alloy
Ian