Lead/ Mazac reaction?

[RonnieS]

Seeking to add weight to a Bachmann Modified Hall I was pleased to note that the manufacturer had a 5,5mm wide mazac weight in a 8.5mm wide hole.

So my first thoughts were remove said weight, saw off plastic box, stuff hole with lead and gain 35g. Then my second thought was that some where I had read that mazac and lead in close proximity cause a nasty reaction.

Can anyone comment on this. Is it a fact or not?

Regards

 

[Fat Controller]

58 minutes ago, RonnieS said:

Seeking to add weight to a Bachmann Modified Hall I was pleased to note that the manufacturer had a 5,5mm wide mazac weight in a 8.5mm wide hole.

So my first thoughts were remove said weight, saw off plastic box, stuff hole with lead and gain 35g. Then my second thought was that some where I had read that mazac and lead in close proximity cause a nasty reaction.

Can anyone comment on this. Is it a fact or not?

Regards

 

I thought the problem arose when the lead had been incorporated in the MAZAC/ZAMAC when it was molten, not just when the two were in close proximity in solid form.

[Michael Hodgson]

The problem with mazak is that some of it spontaneously disintegrates.  With or without lead nearby. 

It seems to be a characteristic of the particular batch of mazak and the ingredients/contaminants present in the alloy.

Other batches can be OK.

[Nearholmer]

I’ve never heard of simple contact causing the rot, only pollution by lead during the casting process, but if you want to be sure to be sure, you could always paint the parts before assembly to act as a barrier.

[stewartingram]

Ah, but what if the paint contains lead......

 

I'll get my coat......

[Fat Controller]

38 minutes ago, Nearholmer said:

I’ve never heard of simple contact causing the rot, only pollution by lead during the casting process, but if you want to be sure to be sure, you could always paint the parts before assembly to act as a barrier.

Not so much the casting process, I thought, but during the refining process. Certainly Imperial Smelting at Avonmouth used to send wagonloads of lead/ zinc amalgam from their refining plant to Holland, for furthering refining.

[Nearholmer]

One trad form of pollution in the toy industry occurred due to insufficient separation/cleanliness during casting in places where both materials were in use, but, yes, insufficiently refined material too.

 

Presumably recent cases are the latter, Bebe aide I can’t imagine any lead-castings being made these days.

[goldfish]

4 hours ago, RonnieS said:

Then my second thought was that some where I had read that mazac and lead in close proximity cause a nasty reaction.

 

Lead/tin solder was commonly used to fix mazac castings in place, and I have never heard of it causing a problem.

[RonnieS]

7 hours ago, Nearholmer said:

I’ve never heard of simple contact causing the rot, only pollution by lead during the casting process, but if you want to be sure to be sure, you could always paint the parts before assembly to act as a barrier.

Sounds like a plan

[Il Grifone]

I always try to avoid contact between dissimilar metals. There is always a risk of electrolytic corrosion. paint is not a good insulator (at least when you want it to be!), so a sheet of insulating material goes between them.

[Nimbus]

The Hornby-Dublo 8F body was a mazak casting was it not? In its forward boiler section

was fixed, with a countersunk screw, a yellow-painted ballast block. In raised lettering

was cast the word "LEAD". Plenty of those locos survive today!

 

The Nim.

[RonnieS]

Seems like it will be OK. If it reacts its well away from any moving bits. Several posts on here (on adding weight) stick lead onto existing mazac weights. Thanks to all who posted.