Mazak

Hi All.   I have found a problem on line with the use of "Mazak" in Hornby Locos and Class 31 seems to be in the frontline , there maybe other classes? But the article I found mentioned Class 31 in particular .The Mazak is distorting, but why now? Hornby have been using the stuff for ages. Please advise.  Kevin

This is is a very well known fault of the this alloy (discussed many times on here), which breaks down over time with cracks and finally disintergration, rendering the loco useless. I have some examples myself. Repairs are only ever temporary, as the 'illness' returns. The solution is to build a new chasis. Such locos are not for the faint hearted, so are better avoided if you have the choice Kevin.

Bill

Hi Bill. Thank you for your reply . The thing is, that the Locos were purchased in the 21st Century and still under guarantee . And when they have been returned to Hornby , the purchasers are told "No Spares Available " and receive a credit note.     All the best. Kevin

Rather than a credit note Kevin, I would insist on a full refund, as provided for under the 'Sale of Goods Act'. The retailer cannot realistically refuse, as the goods are not suitable for purpose and spares unavailabbe.

If everyone did this, perhaps Hornby would use a more sustainable material.

Bonne courage,

Bill

Hi. Bill.   Good idea. But fortunately for me, I am not in the same boat, I have only read about others.        All. the best. Kevin

Argh, I made a rare schoolboy error when reading your posts in thinking you had a problem, with a loco that is.

Sorry oops,

Bill

Hi Kevin,

Tin contamination of the zinc in MAZAC. Also apply applies to white metal alloys, where it's usually zinc contamination of the tin. Well known problem, there is no cure. Exposure to cold doesn't help.

Nigel

Hi Nigel. Thank you. I have been reading more about Mazak, and the problem isn't exclusive to Hornby.Bachmann too, it could be international ? All the best Kevin

Kevin, more to read about the problem
Mazak 'rot' ... arrghhh! - Hornby - RMweb

Hi Kevin,

This problem is older than model railways. These days it all depends on good QC and good QA. Tin is difficult to distill from zinc, there are well defined limits of contamination of each in the other to avoid the problem. If the caster uses cheap zinc, the "pest" will surface 5-10 years down the road in the alloy. By which time it's too late. And there really is no fix. It's a DODO.

Nigel

Hi Ron.   Thank you for your reply. If the Mazak problem were to , it already has?, spread to the motor industry and beyond. "God Help Us All". Cheap imports ? Fast Buck ? The mind boggles, with so many US companies buying from China who knows where it will go next?   All the best. Kevin

Hi Nigel.  In my reply to Ron/Sol. I mentioned cheap imports and foreign made stuff formerly made in the US.It really is frightening. I certain that NASA wouldn't stoop so low . But a lot of goods that you would expect to be made in the USA have been or seem to have been made in Asia . Any comments??  Kevin

Hi Nigel.   Thank you.  This is a second reply , I don't know about metallurgy  and the constituent ratios of the metals of Mazak. But "back in the day" when I used to melt lead, I read about adding Zinc to the lead to get a tougher? weight, as the lead was soft. At that time I noticed that when the lead was in the molten state "Dross" floated to the top. Whether or not that is the same in the production of Mazak I don't know,   or if someone is "cutting corners"???       All the best. Kevin

Hi Kevin,

It's not a question of cheap imports. Back when the model locomotive manufacturers did it in house the process was poorly understood, and lots of MAZAC with "pest" was produced. Early G-F and Hornby locomotives are an example. Over here Lionel ZAMAC (same stuff) wheels from the 1930's and 1940's often fall apart when looked at. These days it's all down to quality control (testing) and quality assurance (making sure the tests were actually done). Unfortunately it's a long chain. Bachmann/Dapol/DJ/Heljan/Hornby and anybody else contract the manufacturing to a Chinese company. They subcontract the casting of the MAZAC chassis. The caster subcontracts the production of the alloy to another company. They buy the ingots of individual metals from a refining/distillation company (or companies). Pure zinc is expensive, zinc with low levels of tin less so. Until the process was better understood the MAZAC was often prepared from the individual metals in crucibles that had been been used for white metal melts, primarily lead and tin plus a few exotics. Which resulted in cross contamination. White metal casting failures from old kits are probably more common than MAZAC failures. It seems to have gotten better recently, but I suspect there will always be a low level of "pest" occurrence. I stopped buying K's kits for this very reason (although the issue there is the body, not the chassis, which is a low-tech brass bar affair).

Even with contamination that chassis is usually good for 5-10 years, often a lot longer if not subject to temperature fluctuations (which result in changes of the zinc crystals, unheated garages are probably the worst place to store a MAZAC chassis). The parts that fail are usually thin pieces such as motor/bogie mounts that are subject to strain. They can usually be temporarily repaired with bits of brass, bolts, screws, epoxy or CA (or even soldered for the adventuresome among us) but it's a bit like slapping fiberglass filler on a rusted car panel. The repair will fail. I've found it's a diminishing returns exercise, 5-10 hours of work to get a chassis that fails again in 3-6 months.Unfortunately after all this time the supplier has long run out that spare chassis you need, or the design changed, or they stopped making the model. Or went out of business. Buying a used chassis may or may not get you one that's stable. The solution of course is a brass chassis if you must have that locomotive and a new one is not available. I've never felt that I must have a particular locomotive, or that it's worthwhile trying to repair one with the "pest", but if you do have one with the disease then a new custom chassis is the long-term answer.

Nigel

Edit: And no, I'm not a metallurgist.

Hi Nigel. Thank you for your reply. You have been busy, I was banking on the DJModels hype? Also that of Kernow.There is another company, "Sutton Locomotive Works" which have a very "Flashy" set of adverts, does that mean that company would be likely to "contract out" their Work as well.   All the best. Kevin

Hi Kevin,

Ask them. I suspect the answer will be "yes" (if they bother replying). Kernow definitely does, hence those delivery dates that keep on changing. At best the CAD diagrams are done here, then sent there. I'm not aware of any manufacturer who makes their own MAZAC chassis'. Same over here. One of those cases where more expensive doesn't necessarily mean better quality.

Nigel

Hi Nigel.  That sounds like unsound business practice to me = more profit at the risk of poor customer relations.If the Chinese live in a "throw away buy new" society then they are either all millionaires or the West are paying overinflated prices. They have come a long way since the student riots in Tiananmen Square.
All the best. Kevin

Hi Nigel.  White Metal models i.e. "Dinky", "Matchbox" and "Oxford" to name a few, the other thing they all have in common is a high Gloss Paint, appealing to young eyes?? But also it protects the material and covers a multitude of sins. Which leads me thinking "way back when" I had a mixed collection of toys which believe it or not, I would put away each night into their boxes in trays in a cupboard, thus preserving them. We know that model railway enthusiasts are also careful. This may be on the wrong track, but considering how these models have not only held their value but have gone through the "Proverbial Roof" . The difference most likely being "Quality Control" but those inscrutable manufacturers would not want anything to do with "QC". Any comments ??   Kevin

Hi All,
Keven actually sent me a PM asking my opinions and thoughts on this matter; I relied to him but thought it is probably worth posting my opinions (edited very slightly to clarify one point) for everyone to see and discuss further if desired.

*****

Hi Kevin.

The mazak rot problem applies only to a few particular model releases from each of the major manufacturers: Hornby had one of the Brush type 2 (class 30/31) models plus some T9 locos, Bachmann had the early N class and a 9F, Heljan had one of their class 47s.

The problem goes back well before that. Certain Dinky Toys from either side of WW2 have been known to crumble away to nothing, or have bits just drop off.

I had the problem with my Hornby class 30, which started off as D5512 but got renumbered to avoid a clash of numbers when I was only using 2-digit address for my early DCC dabblings. Mine took quite a long time to exhibit any symptoms (the body corners showing a few cracks), possibly because my models are stored indoors in a house with central heating, so they are rarely exposed to extremes of temperatures or excess humidity or dryness, which could exacerbate and accelerate the effects of the mazak cancer. By the time I approached Hornby for a replacement chassis, they had no fully running chassis available, but did offer me a replacement chassis block for me to swap the innards into. I was happy with that solution because I had done so much work on the body of mine, not just renumbering, but updating to later condition with no duck egg blue cab window surrounds and with small yellow panels.

As far as I am concerned, the manufacturers affected have tried to do the right thing with their customers; Hornby were offering vouchers after the chassis ran out, although I would have insisted on a direct equivalent replacement if push came to shove; Bachmann sent out replacement footplates for the affected N class locos; and Heljan offered replacement chassis for their faulty ones. Bachmann also sent out replacement bodies for the blue 2 EPBs with the wrong coach numbers, and Hornby sent out replacement PCBs for the faulty early issue class 50s and complete replacement bogies and coupling mechanisms for the early issue Pullmans, all at no cost to the customers.

The problem has not been a widespread one, and we have to accept that occasionally things do go wrong in the manufacturing processes. As long as the manufacturers support their customers properly, within reason, I don't think we have much to complain about.

On the other hand, Dapol are very poor with their customer support and communication. They gave no support at all for the faulty PCBs on their class 73s, wrong colours on the 73s, and limited support for the faulty printing on their DRS class 68s (buyers of the latter can get replacement bodies, as long as they pay the postage costs of returning the faulty one and of Dapol posting out the replacements). As you can probably tell, Dapol will not be getting much extra custom from me, nor will I be recommending their stuff to other modellers.

As for Sutton's Locomotive Works, their support is excellent. My second class 24 from them with sound was issuing a few pops and clicks on top of the 'proper' sounds. They replaced the decoder at no cost to me. I returned the faulty one but it disappeared in the post somewhere and never got to them, but they have been perfectly understanding and said not to worry about it.

Hi Kevin,

It's not about throw-away and profit margin. It's primarily about quality control since the issue became understood. Jeff is spot on, don't expect a spare chassis for everyone sold or for a twenty year-old model.  Plus how long do we have expect a model locomotive to run? Five, ten, twenty years? I think twenty is a good run. I've had 2 MAZAC chassis with the pest in some 200 over the past fifteen year. And they were both over twenty-five years old. The failure rate on white metal kits is much higher, but only with old castings from the 1960's-1980's.

MAZAC is just the right density for HO/OO/N scales, the pest is a very minor issue that affects some production runs. If you have spent a lot of time and money (50 hours plus parts for example) in detailing the shell that's a big investment that justifies getting a new detailed brass chassis that will still be running 50 years from now.

Nigel