broken stampers 12" help needed!!!

[andybee]

Hello pressers!

My 12inch stampers are mostly all crushing after some records.
The problem is arround the center bush.
Some say, it comes from preforming, some say, maybe nickel is bad,
maybe my clamp ring is not good...
any suggestions?

Thank you!

[Aussie0zborn]

Is the stamper cracking around the centre hole, at the point where it's formed to the shape of the centre bush?

Stampers usually crack around the outside edge on the gate of the mould.

They crack because the nickel is not ductile enough.

Why would the clamping ring have anything to do with the stamper cracking in the centre?

[montalbano]

Hi Andi
Please check your pH. You're running too alcaline, maybe.
One more thing comes in mind to me. I don't know how you manufactured the baths or modified the ones I gave to you, anyway, speed baths should have an extra pipe pumping extra sulfamate in the center. This is done to compensate the centrifugal effect during the deposition, in order to have an even thickness of the stamper from the center to the outside.
So ... please check pH (around 3., and then measure the thickness of the stamper in the edge and in the outer diameter.
Let me know!

[klikli_ska]

Very interesting post.

It happened to me as well!

Andy, is your problem like the picture one? We have the same problem in the stamper center edge...

[mossboss]

Plating issues I see
Both post's indicate a very brittle deposit
For a ductile deposit so the stampers will last at least 1000 pressings, is to get at least 5 x 90 degree sharp bends out of a strip 10 mm wide and about 50 mm long
This needs to be cut out (of the non cut/groove area), around the stamper held tightly on the jaws of a pair of pliers which meet, than bend left 90 degrees straight than bend right 90 Degrees
Ideally you should get 7-8 bends, if you get 4 bends you are on a border line case may be you get a run out of that stamper, any less than four, forget it
If you not getting good results obviously, the chemistry in the baths is up the shit or your plating conditions are way out
Ductility is the aim of record matrices
Bath conditions have been posted here which are a good guide to start off with, also your chemical supplier should be consulted
It is not easy to just answer the question unless all operating parameters as well as bath conditions are known
Absolutely no doubt that it is a highly stressed deposit which will break in a few pressings assuming it is not already cracked at the center hole forming stage which is a good indication of a stressed deposit
If you hear crackles while you cutting off the excess on the circle cutter it will most likely crack while forming the center and the outside It is a distinct crackling sound which is not present when the deposit is good
If that's the case don't bother putting it on the press guys it will split in no time
Heating up the center to temper it so it will not crack as I have seen in a photo here, its a good indication of bad plating
It may be OK for a 7" stamper, very doubtful a 12" stamper will be able to last the distance if it is also tempered so as to form the center hole
No one who does galvanics in the industry does that!!! there is no need for it if you have a good plating facility also know what you are doing
They get their baths working well, depositing a ductile, very low stress deposit, the industry has been doing for many many years with millions stampers having been made in the past still made today
If you cannot flatten out the center after it has been formed, and reform it, as it is some times done, when you have an off center record, you are wasting your time, your deposit is to brittle
Not that easy to do galvanics but not that hard either It takes a few years to master the art that's for sure but it is achievable, perseverance, time, and good advise which is followed will get a result
Mixed advise sought from many sources it is not going to solve the problem
One needs to follow through every step working with one set of parameters until all of the issues have been resolved,
A good start is to get a good chemical balance in the baths,
pH, sulfamate qty, Dissolved nickel qty, Boric Acid qty, Temperature,
Dummy the baths so as to remove traces of tramp metals
Carbon and peroxide treatment so as to remove organics as well as any Iron that has not been removed by dummying
Than you have a starting point with KNOWN parameters
Additions to the baths may be required, after the adjustments, do another chemical test assuming you meet the parameters you are good to go
Adjust plating conditions according to known settings from the past
You get a result
It works
Going a bit here and a bit there, he said this, he said that, will only get you into more trouble with no results



Cheers

[andybee]

Thanks for your support, thanks also for your post, Chris!
Yes, looks exactly like my problem.
I think also, that the nickel is not ductile enough.
Thanks again for the help!!!!
Andreas

[mossboss]

Sorry Guys
Long post to help out just disappeared. WTF
Will have another go at it some other time
Brain is just cooked at present also I am pissed off big time
It took ages to write, it just went to nether land
Cheers

[mossboss]

Ok Had to rethink most of it as well as use my notes as the last one evaporated into nether land
Lets see if this post will disappear Ha
Producing Matrices for records the following Characteristics are desirable,
An amorphous deposit
Fine grain deposit
High Ductility
Low internal stress

Nickel sulfamate baths, as we use now days will provide the above desirable characteristics
The baths were known as a Barrett's bath, as against the common, and still in use Watts bath
Nickel sulfamate has the following advantages
Low stress, Ductile deposit
This is achieved by the sulfamate Ions, contained in the solution
Sulfamate as well as the dissolved nickel metal are both Ion donors

Composition of the bath

Nickel Sulfamate 450-550 ml/L
Nickel 76.5 Grams/L
Boric acid 25-35 Grams/L (Temperature dependent, see Note 1)
Nickel Chloride 6 Grams/L (see note 2)

Operating conditions,
All based on 14" lacquers

Depolarised Nickel anodes are preferred
These are called D or S nickel crowns or balls
Electrolytic anodes require to high an amount of Nickel chloride which is not preferred for our application Only in an emergency they could be used
Anode to Cathode, 1-1, Typical Record matrix baths have greater anode area (good)
Density 29-31 Be
pH 3.6-4.1
Temperature,
Lacquers Pre Plate 38 C Max,
Master or Positive on Lacquer 45 C max
Metal to Metal, Stampers & Mothers, 50-59 C maximum

Current Density,

Pre plate Lacquers, max 30 amps,
Lacquers after pre plate 80-90 Amps if temperature at around the 45 C Less current at lower Temp's
Metal to Metal assuming there is a cooling system installed in the bath up to 250 amps
If no cooling system is available a maximum of 120 amps should not be exceeded as the solution will overheat breaking it down Maximum Temperature for a Sulfamate solution should be no more than 60 C

Filtration:

1-2 micron filters in line to the supply from the sump tanks should be used The pump should have sufficient capacity for 6 plus changes per hour In other wards all of the solution should go through the filters no less than 6 times per hour If you have a 1500 L tank capacity the pump should be able to do at least 9000 L per hour
It is nice to have pressure gauges on the inlet and the outlet of the filter Any variation more than 2% on pressure indicated will point out to the filters are getting loaded up, blocked filters create havoc with blown lines and inconsistent liquid supply to the plating cells
The high filtering ratio also assures solution uniformity as well as good filtration to remove impurities


Dummying:
Experience over many years by many has established that on going dummying at 5 amps against a copper plate hung in the tank where the pump and filter is located Two Bars are required also a separate DC power source A basket of nickel anodes on one bar a metal plate on the other, copper is fine about 1 sq foot is OK
A nickel metal plate from a lacquer negative also works well
A good DC source is a 6 Volt battery charger at around the 10 amps
Voltage between the bars should be around 1 volt once immersed in the liquid with the power supply on

Note 1:

Boric acid content:
The baths should have enough boric acid to saturation, boric which acts as a pH buffer This is achieved by just hanging an anode bag filled with about 1 KG of Boric hanging inside the bath The solution will take the amount it requires to saturation according to the temperature in the bath
Boric acid will precipitate out of solution if it has been allowed to accidentally or deliberately to drop in temperature
It is quite hard to get it back into the solution so avoid this if you can
Sulfamate concentrate has just enough boric acid so it does not precipitate out of solution while in storage, we normally add boric acid when we make up a new bath the bag suspended in the bath does it nicely Make sure you inspect it, top it up if it needs it

Note 2:

Nickel Chloride:
Nickel Sulfamate baths will run quite well producing a low stress deposit without the addition of any Nickel Chloride, However anode corrosion is quite poor, Nickel chloride is added so as to promote anode corrosion If you can run without it than that's good Keep an eye out to make sure the anodes have not passivated also use lower current settings by 20-30%

Anti Pit and wetters:

These are propriety additives which help with lowering the tension of the solution as well as leveling the deposit Use about 10% of the recommended dosage
Make a 3" or 75 mm, complete ring out of 1-2 mm wire allow for a handle or a hook where you will twist it to complete the ring Use it to determine tension of the solution If dipped in the liquid it should hold a film of it for say 20-30 seconds before it pops
Be aware these are organic based materials which will break down Their breakdowns products will result in tensile brittle deposit
If you have used the recommended addition and you are getting brittle deposit, carbon treat the bath also use peroxide to remove all organics Start with a 10% or less than add minute amounts until you got it right It is right when no pits at the back of the deposit and the film stays on the 3" ring for 20 seconds or a bit more

pH Fluctuations:

The baths have a tendency to a raising pH If you start at a pH of 3.6 don't panic pH will raise slowly keep it at around the 3.8-3.9 Electronic pH testers are fine but always keep some test strips to use a reference Small additions of sulfamic acid will bring pH down If you have started with a pH of 3.6 and you find that it has gone down you need to check the Boric acid bag if you have one

Daily Control:

Density and pH will tell you most of what you need that is assuming you started with the above parameters

Danger Points:

Don't allow the nickel anodes in the baskets to become depleted It alters the anode to Cathode ratio altering operating parameters as well as that there is a danger you will strip the dissolved nickel out of the solution requiring expensive concentrate additions
Make sure the Boric acid bag is always full and well covered with solution
Use distilled water for additions to start of with If all is well than you may go to DI water If the baths play up revert back to distilled water while you check the DI water in a lab
Prevent temperature variations as once again the parameters are changed as well as presenting the danger of the boric precipitating out of the solution
If you are going to shut the baths down for any length of time and for any reason make sure you drain the liquid out of the pump(s) as well as the filters
I will post some testing of the solution procedures methods next post
Best of Luck
Cheers