Model Boat Mayhem

Technical, Techniques, Hints, and Tips => Engineering Techniques and Materials. => Topic started by: Brian60 on May 10, 2014, 11:30:38 am

Title: Blackening brass
Post by: Brian60 on May 10, 2014, 11:30:38 am

I  need to blacken some brass parts and understand this can be done chemically. I don't want to paint them as they are so small and the paint is liable to flake off so a chemical solution would be ideal.

My problem here is being in Spain access to model/engineering outlets is considerably limited. Is there any household products that might come into use? I need about half an eggcup full of whatever at the most, so again I don't want to be paying out lots of dosh for  litre's of stuff!

Title: Re: Blackening brass
Post by: derekwarner on May 10, 2014, 11:57:04 am

Brian....try a leadlight glass merchant...this does work & is relatively inexpensive................Derek

Title: Re: Blackening brass
Post by: Brian60 on May 10, 2014, 06:29:02 pm

Thanks Derek, trouble is there is a distinct shortage of leaded glass in Spain! most homes have ornamental metal bars over windows to deter burglars- even on the second, third and higher floors!

Looks like I'm going to have to experiment, blackening agents use copper carbonate with ammonia ( internet search!) so I'll be off to the garden centre tomorrow looking for fruit tree treatments, apparently that contains the copper %%

Title: Re: Blackening brass
Post by: derekwarner on May 10, 2014, 11:31:49 pm

Brian....if you have success with a brew for blackening brass let us know the detail  :o........Derek

Title: Re: Blackening brass
Post by: Umi_Ryuzuki on May 11, 2014, 03:34:19 am

See if a local tall ship modeling supply house might have "Liver of sulphur".

If not, try the local pharmacy or jewelers supply...  :-)

Title: Re: Blackening brass
Post by: Brian60 on May 18, 2014, 05:47:12 pm

Well forget about using the plant treatment method! It only contains a maximum of 30% copper sulphite. The copper sulphite has to have baking powder added to it to form copper carbonate, this mixture is then mixed 50/50 with ammonia to form the blackening agent.

However I am on the track of some copper sulphite powder over here in Spain, it is freely available cheaply in the UK ie- £1.99 for 200 grams, but the postage to Spain was £15 %% If the worst comes to the worst I'll get my son to buy a sachet from Ebay and mail it out to me.

Title: Re: Blackening brass
Post by: BarryM on May 18, 2014, 10:44:41 pm

I have used Birchwood Casey 'Brass Black' which I purchased on line. However, I understand it is also used by gunsmiths and so if you can find one of them in Spain, you might strike lucky.

Barry M

Title: Re: Blackening brass
Post by: Brian60 on May 19, 2014, 12:33:24 pm

Thanks Barry. Gunsmiths there are a plenty! Its not illegal to own a gun in Spain and around here where its all rural the police encourage it- not only for hunting!