Odd coloured cases after tumbling

[cheshirelad]

Help, I'm in the middle of processing 1000 Lapua .308 cases and need some advice.

Doing them in groups of 250, first 2 groups no problem, third group have come out of the rotary tumbler almost rose gold colour.

Normally I use a squirt of washing up liquid and a half teaspoon of citric acid to prevent water marking.

Unfortunately today I picked up Stardrops instead of Fairy liquid, no idea if I've compromised the cases.

Any help appreciated.

[gruntus]

Hi Cheshire,

You haven't compromised your cases at all so don't worry about it, they just won't be as much bling on the range and will come up the same in your next cleaning cycle.  

I usually use 1/2 a tablespoon of Ariel Actilift Gel and a 1/3 of a teaspoon of citric acid for 50 - 100 cases.

I haven't tried Fairy liquid before, how much do you put in?

All the best.

G 🙂

 

[One on top of two]

If it’s bling you want , try soda crystals, approximately one large tablespoon per 100 cases and one teaspoon of lemon juice . 
 

then dig out your sunglasses 😎 

[BlueBoy69]

After getting a wet tumbler and thinking I can't be assed with trying to get hold of 'Lemishine', I just made up an analogue of it.

1/4 teaspoon of citric acid

1/4 teaspoon of sodium bicarbonate (baking soda)

1/4 teaspoon of washing up liquid

These are added to the warm water and cases in each drum of the wet tumbler.

[Popsbengo]

1 hour ago, BlueBoy69 said:

After getting a wet tumbler and thinking I can't be assed with trying to get hold of 'Lemishine', I just made up an analogue of it.

1/4 teaspoon of citric acid

1/4 teaspoon of sodium bicarbonate (baking soda)

1/4 teaspoon of washing up liquid

These are added to the warm water and cases in each drum of the wet tumbler.

doesn't the sodium bicarb just react with the citric acid ?  I just put a level teaspoon in my ultrasonic cleaner (about 2ltr) with some detergent and the cases come out sparkly clean.  Rinse in plenty of cold water and dry. 

To the OP;  rose gold implies a removal of zinc from the brass surface leaving a microscopic copper sheen.  From what you describe I wouldn't worry, it's only a surface effect.

[John MH]

Always use cold water.

[gruntus]

11 minutes ago, John MH said:

Always use cold water.

Hi John,

A respectful question, why cold water only? I've always used warm water for initial wash and rinsing off.

Thanks in advance.

G

[meles meles]

Warm water will increase the rate of the reactions going on in the cleaning solution: not necessarily a bad thing.

Arrhenius (google 'im) showed that increasing the temperature of a reaction by ten degrees doubles the rate at which it proceeds. Hence if you use boiling water to make tea you only need to have your tea floarting around in the pot for a few minutes before its ready to drink whereas if you use cold water it will take several hours to attain a decent strength brew. The process is reversible too, every 10 degree reduction in temperature halves the reaction rate, hence why we chill or even freeze food to slow down the decay.

Using warm water when you clean cases will speed up the reaction between the acid and the brass, making the process faster. However, if you clean for the same length of time as you did with cold water then you'll potentially leach away a little of the zinc from the surface of the brass.

[John MH]

Something I read somewhere about case discolouration when using warm/hot water. I did get some funny results once when I used water out of the kettle hoping that I could cut down the tumbling time, cases had a funny purplish tinge; put them through again with cold water and all ok.

 

[No i deer]

Just a thought..!!

I'm not sure if all this wet tumbling over cleaning is bad for the cases from slowly making there dimensions smaller..

A gentle clean in a dry tumbler or ultrasonic bath would be much better.. 

I generally use a fine wire wool and a cordless screwdriver but that probaly just as bad but it takes only a few seconds for each case🙄.

[John MH]

2 minutes ago, No i deer said:

Just a thought..!!

I'm not sure if all this wet tumbling over cleaning is bad for the cases from slowly making there dimensions smaller..

A gentle clean in a dry tumbler or ultrasonic bath would be much better.. 

I generally use a fine wire wool and a cordless screwdriver but that probaly just as bad but it takes only a few seconds for each case🙄.

Not an issue.

[BlueBoy69]

1 hour ago, Popsbengo said:

doesn't the sodium bicarb just react with the citric acid ?

Doesn't seem to. Well, one of the Lemishine the ingredients is sodium carbonate (soda crystals), so sodium bicarbonate is pretty close, both are mildly alkaline.

Whatever the case, the cases come out shiny with no discolouration.

As you do, I rinse them with cold water, wipe them clean, then put them somewhere to dry. Either on the top of the radiators (winter) or in a fruit drier (summer). 

[No i deer]

I have my doubts John.

There has to be some wear going on especially metal to metal but obviously I've no proof nor will i look for any but it does seem obvious that there will be as one metal is harder than the other....

[VarmLR]

I wouldn't unduly worry about case wear if rotary tumbling but would think about chemical reactions of anything used.  Citric or Lactic acids dosed at 6 to 10% should be fine and cold rinsed afterwards.  I use these for my coffee machines too to descale the inners and they're recommended for anything containing brass or copper or steel without any danger of damaging the metals.   Different water areas have different chemical compositions of minerals, and differing alkalinity so may be more prone to reaction with the brass surface depending on exposure time and temperature.  It's rarely a concern though as no galvanic corrosion or reaction takes place within the main body of the brass, just on the surface.

Personally, I just dry tumble mine in a mixed walnut/corn cob media with half a teaspoon of non-ammonia polish before annealing and sizing, then follow up with 10 to 15 minutes in an ultrasonic bath before the cases go into a hot air dryer.  They're invariably shot out by multiple firings long before these methods of cleaning do any harm whatsever so knock yourselves out but just take care not to use anything with a strongly reactive acidic or alkaline agent that could weaken the alloy.

[No i deer]

I use a 338 lap mag case to throw my charge into then poor it in the pan. This case I used as an alternative check weight. Occasionly I would weight it and it was getting lighter..

I didn't give it much thought until something was said on another website about handling your check weights.. I've loaded thousands of rounds using this case and now it's  over 2/10ths of a grain lighter..!!!

[baldie]

Modern tumblers such as the LEM use pins designed for tumbling Gold.

Cant see a jeweller putting up with material loss.....

Cheshirelad......are you using Goat juice ? if so, you need to rinse the cases in panel wipe or thinners before you tumble them. The lubricant won't come off in the tumbler easily, and ends up discolouring the cases.

[Tony1954]

I use the LEM cleaner and pins , But found a after  re sizing some Martini Henry cases the cleaner was slow to clean and cases were left dull, this was due to the amount of lube left on the cases ( as baldie points out )  This left the pins almost black with lube, so I ran the cleaner with hot water and a dishwasher tablet result pins like new. The next batch of 308 case were cleaned with hot water and dishwasher tablet ( the cheap ones £2 for 40 ) this reduced cleaning time and I think the brass is cleaner, swilled in rinse aid and drained then fruit drier .  

[Brillo]

On 12/30/2019 at 10:17 AM, Popsbengo said:

doesn't the sodium bicarb just react with the citric acid ?  I just put a level teaspoon in my ultrasonic cleaner (about 2ltr) with some detergent and the cases come out sparkly clean.  Rinse in plenty of cold water and dry. 

To the OP;  rose gold implies a removal of zinc from the brass surface leaving a microscopic copper sheen.  From what you describe I wouldn't worry, it's only a surface effect.

As Pops says. The usual process is to rinse with bicarbonate after cleaning to neutralise the citric acid.

[cheshirelad]

Tumbled 2 more batches yesterday and everything is back to shiny normal, I think it was too much citric acid, thanks to everyone for their help.