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[Dennis C]

From Tekcast.com website

ZAMAK
We carry ZAMAK (MAZAK) standard commercial grade Zinc Pressure Die Casting Alloys.
ZAMAK #2, #3 and #5 are available priced per pound. Sold by the lb., minimum ZAMAK order 100 lbs.
Due to market fluctuations, metal prices are subject to change
please call for current pricing.

[John R]

Thanks for replies, one and all. A little digression about Mazak; a few years ago I went to a talk about antique model railways. Model locos were die cast in Mazak, but nowadays good ones are hard to find because the alloy often crumbles and deteriorates. The reason for this is that the pellets for the die casting machines were supplied in sacks that were fastened by a soft metal, probably lead, closure. It seemed to factory workers like a sensible idea to dispose of the closure by chucking it into the hopper with the pellets; it must have seemed like recycling! However, the introduction of the lead messed up the composition of the Mazak to a point where it was unstable in the long term. The same thing may happen to old carbs for all I know.

[Scalyback]

MECCANOYou been reading about the meccano factory. Before WWII they chucked everything in, steel bands from the packing, foils from cigarette packets, etc. By the end of WWII, they cast some of the best Mazak around.


Moral... don't mistreat or drop an extremely rare pre WWII dinky aeroplane otherwise it might shatter into little shards and dust.




"Mazak is an alloy consisting of approximately 94% Zinc, 4% Aluminium and 2% Copper and a tiny amount of Magnesium.  Miniscule amounts of impurities such as Lead or Cadmium; as little as 0.008% of Lead or 0.006% of Cadmium can cause severe inter-granular corrosion leading to what is referred to as 'metal fatigue'.  I could go on to explain in some depth how the impurities attack the granular boundaries which can be accelerated in damp conditions and give you the science behind the problem but it will not help you save your model which will eventually disintegrate.


If a model is produced from contaminated Mazak then nothing can be done to stop the corrosion, however the process can be slowed by ensuring that the model is always kept in a dry atmosphere. If you have early models that do not show signs of metal fatigue by now then the chances are that they were manufactured with a 'pure' alloy and will not develop fatigue. You can often find models that show metal fatigue in certain parts and not others for example a perfectly fine body with heavily fatigued wheels simply because the parts were manufactured separately at different times with a different batch of Mazak."

[Scalyback]

[center]


Zamak? Wasn't that Dave Dee, Dozy Beaky, Mick & Tich?