andyman7 Posted October 5, 2013 Share Posted October 5, 2013 This Triang Jinty arrived in the post today and immediately on examination I could see that the rear casting in the chassis block had suffered mazak contamination. I've posted it here because its so unusual to see this in a Triang loco - Hornby Dublo suffered from it pre-war, whilst Trix and Graham Farish had their issues (and virtually every motor bogie from the 'Ever Ready' Underground train set has crumbled to dust), but in this respect Triang is very very good and I have never seen this problem before in 30 years of collecting. Indeed, modern Hornby and Bachmann have had more occurrences of faulty mazak castings than Triang ever managed. This must have been a very rare faulty batch. The front block was fine, and fortunately these chassis are plentiful as s/h spares - I had one in the box so was able to sort the loco. Link to post Share on other sites More sharing options...
mossdp Posted October 6, 2013 Share Posted October 6, 2013 I had a 1960s made Jinty with a similar problem (one piece chassis, through spoked black wheels). The chassis had grown more than 5mm. As you say, an extremely unusual occurrence. Like you, the only one with such a problem I had ever come across in decades. However, I believe that the castings of some of the synchro smoke units fitted in some models did suffer from this, maybe more often, but again certainly not a common problem. Link to post Share on other sites More sharing options...
RosiesBoss Posted October 7, 2013 Share Posted October 7, 2013 Hello, I've also had a few locos with similar problems: Rivarossi Bourbonnais 0-6-0 tender loco, where the tender drive chassis siezed due to Mazak cancer. It still awaits a replacement chassis. Lima 4575 class 2-6-2T, where the cast ballast weights tried to make the body explode! Hornby "Toby" chassis, where the motor/gear mounts disintegrated when disturbed as part of a kitbash exercise. (See page 6 of http://www.rmweb.co.uk/community/index.php?/topic/72460-gwr-1331-ex-whitland-cardigan-0-6-0st-project/ for a picture.) As modellers, it seems that it can be just a matter of luck whether an old model develops this fault or not. I just wish there was better quality control at the factories. Regards, Rob Link to post Share on other sites More sharing options...
andyman7 Posted October 7, 2013 Author Share Posted October 7, 2013 I think that was why I was surprised enough to make this post, because Tri-ang's quality control was so good. None of the models you mention are Margate made (Triang or British made Hornby), and given how the issue crops up repeatedly it seemed worth noting how good their output has generally been - their 1950s wagons all had Mazak chassis and there are thousands still out there in sound condition! Link to post Share on other sites More sharing options...
RJS1977 Posted October 7, 2013 Share Posted October 7, 2013 I concur. My father has a large-ish quantity of Triang locos & stock (I have a few as well) going back 60 years, and none have suffered Mazak rot - indeed I know from my own attempts at chassis modification just how tough Mazak is! It's ironic how in the move from "pocket money" models to super detailed models for those who can afford them, the actual build quality of models seems to have suffered :-( How many of today's China-made £100+ locos will still be in service in 50-60 years' time? Link to post Share on other sites More sharing options...
Fat Controller Posted October 7, 2013 Share Posted October 7, 2013 I think that was why I was surprised enough to make this post, because Tri-ang's quality control was so good. None of the models you mention are Margate made (Triang or British made Hornby), and given how the issue crops up repeatedly it seemed worth noting how good their output has generally been - their 1950s wagons all had Mazak chassis and there are thousands still out there in sound condition! Surely the quality-control issue is at the metal refiners who provide the Mazak to the model manufacturers? I doubt that any model manufacturer would employ a metallurgist to check the composition of the material supplied, as the amounts used are relatively small, and wouldn't justify their salary. Link to post Share on other sites More sharing options...
RosiesBoss Posted October 7, 2013 Share Posted October 7, 2013 I agree that Mazak cancer is almost unheard of among Margate-made models. I have more than a few of them on "Carmarthen Junction" (see other posts for details). My vintage 1954 "Princess Elizabeth" still works well and shows no sign of it. My brother's Hiawatha, 3Fs, NSWR suburbans - all from the 1950s - also are still ok. It's a pity that such QC systems as ISO 9000 have not prevented supply of impure alloys to today's manufacturers. Regards, Rob Link to post Share on other sites More sharing options...
RJS1977 Posted October 7, 2013 Share Posted October 7, 2013 Presumably with the shift of production to China there's also been a change in supplier of the Mazak, and obviously they aren't producing it to as a high a quality as it was over here (wonder if anyone over here still produces it?) Link to post Share on other sites More sharing options...
Fat Controller Posted October 7, 2013 Share Posted October 7, 2013 Presumably with the shift of production to China there's also been a change in supplier of the Mazak, and obviously they aren't producing it to as a high a quality as it was over here (wonder if anyone over here still produces it?) The main producer was Trident Metals at Bloxwich (formerly part of Imperial Metal Industries); however, I suspect they've closed within the last couple of years. Link to post Share on other sites More sharing options...
Il Grifone Posted October 7, 2013 Share Posted October 7, 2013 I recently acquired a 'King Arthur' (renumbered as a 'Lord Nelson'! but never mind..), fitted with a 'Black Five' chassis which has two wheels suffering from this. It could be poor storage as cold and damp have deleterious effects on mazak. I have had a few 'Matchbox vehicles (usually immune) and a Dublo electric point casing, suffering from mazak problems - the presence of copious rust suggested corrosion rather than faulty material. Early Rivarossi models were particularly prone to this problem, (The Rivarossi Memories website has suggestions for 'cures'.), but I would agree it's rare in Margate products. Link to post Share on other sites More sharing options...
andyman7 Posted October 9, 2013 Author Share Posted October 9, 2013 I had it once with a Margate HST trailing bogie, but other thathat have never experienced it. Tri-ang tended to be more prone to plastic warp, from the cellulose acetate used at first. Generally Tri-ang's build quality was top notch. Yes, cellulose acetate was not an ideal medium, but once impact resistant polystyrene became available in around 1956 there would be no stopping the rise of Tri-ang. Link to post Share on other sites More sharing options...
hallmodelspares Posted December 7, 2013 Share Posted December 7, 2013 A good interesting post mazak casting failure is rare generally on most triang after 1955. i had just recently a jinty tt loco the center wheel on one side had cracked and i have had like mentioned a hst rear bogie disintergrate whilst taking it apart. Duchess Hornby tender drive models from 1977 the chassis metal bottom warp and break and a triang princess with totally cracked centre sections both front and rear Mazak by its very own nature is a mix and it has to be precisely mixed to make a stable metal They say if a wheel was cast for an engine or train and they made around 50,000 models and 100,000 wheels in a batch were fitted around 10% should fail, 20% may develop problems and the rest is okay Compare that 2 the dublo pre war where around anything upto half a run could fail. That said its rare and should not with triang be a large problem Link to post Share on other sites More sharing options...
Il Grifone Posted December 9, 2013 Share Posted December 9, 2013 I understand that wartime research revealed the source of the problem as impurities in the alloy. Pre-war insufficient care had been taken (not surprisingly) resulting in a high failure rate. Post war Dublo (and Dinky Toy) castings are reliable as are Tri-ang and Lesney*. Other makes less so *These are not the only ones, just three major manufacturers that came to mind. Link to post Share on other sites More sharing options...
Ruffnut Thorston Posted June 5, 2014 Share Posted June 5, 2014 I had a 1960s made Jinty with a similar problem (one piece chassis, through spoked black wheels). The chassis had grown more than 5mm. As you say, an extremely unusual occurrence. Like you, the only one with such a problem I had ever come across in decades. However, I believe that the castings of some of the synchro smoke units fitted in some models did suffer from this, maybe more often, but again certainly not a common problem. I can confirm that there were problems with some SS unit casings, though th eonly ones I have seen so far are the smaller type X.392 units used in the 0-6-0, 2-6-2, 4-6-0. ( I have a couple of examples, including black-painted ones from the B12 or 1969 R.59 2-6-2 (or "German" 2-6-2) One casting I have just seems to be badly cast, and out of shape. The loco it was fitted in suffered, as the smokebox "exploded" in pieces at some stage after it escaped from the factory! I managed to re-break the original glued repair, and get the pieces together better. The loco concerned? One of the Railway Children GN&SR "Jinties"! Link to post Share on other sites More sharing options...
edcayton Posted June 5, 2014 Share Posted June 5, 2014 If the problem doesn't show up for several years I don't see how factory quality control would have found it? Ed Link to post Share on other sites More sharing options...
34theletterbetweenB&D Posted June 5, 2014 Share Posted June 5, 2014 ...It's ironic how in the move from "pocket money" models to super detailed models for those who can afford them, the actual build quality of models seems to have suffered :-( How many of today's China-made £100+ locos will still be in service in 50-60 years' time?... As long as they last the purchaser's lifetime that's long enough. The ultimate life of Mazak is unknown. It's a relatively novel material so there isn't many centuries of experience to refer to. What typically contaminates the mazak melt is something like a lead alloy seal on the mazak pellet packaging, or a bit of solder mistakenly going into the pot. Provided the user recognises this as a potential problem, then the quality system should prevent occurences of contamination in the alloy at the melt and cast stage. But that isn't the end of the story as far as a cast piece of mazak is concerned. It may look like a solid piece but at the atomic level components can move about, leaching in and out, and there is corrosion and thermal cycling to be considered to. It may well have a half life under normal usage and storage conditions which hasn't yet revealed itself because the time span of its existence is too short... Link to post Share on other sites More sharing options...
Il Grifone Posted June 5, 2014 Share Posted June 5, 2014 If the problem doesn't show up for several years I don't see how factory quality control would have found it? Ed It can be excused in pre-war castings made before the problem showed up, but once it had it's down to quality control as to the purity of the alloy. The existence of sound pre-war castings shows 75+ years is possible (last a lifetime!) Link to post Share on other sites More sharing options...
RMweb Gold stovepipe Posted June 5, 2014 RMweb Gold Share Posted June 5, 2014 Last year I got my Triang R52S Jinty out of the cupboard it had been in since around 1985, to find the body split in half and the chassis crumbling away. Motor and smoke bits seem ok but the rest is scrap. It's all rather a shame as it was my second ever loco, received as a Christmas present in 1972 and much played with. Link to post Share on other sites More sharing options...
RMweb Gold Culmhead Posted June 6, 2014 RMweb Gold Share Posted June 6, 2014 I've only ever had a couple of issues with Tri-ang (Margate) castings and these were on 1970's models, but with different timescales as regards deterioration. The first was several years ago when I unwrapped a 57xx chassis and it promptly crumbled and fell to pieces! I seem to recall that got it for my 13th birthday in 1972 - it was probably from the same batch as Stovepipe's! The second occasion was last year, when I was test running a 1970's Black Five that kept stopping but continued with a push - it had been running perfectly the previous year. I serviced the tender drive and checked that the loco chassis was free running, but still no joy. I then hard wired the tender drive on the loco feed side only and it ran perfectly, so back to loco chassis. This time I pushed the chassis on live track and found that at the same point of revolution it lost electrical feed, I doubled checked that the valve gear was OK, it was. The culprit turned out to be the centre driver on the live side, this was very slightly oval and was raising the two other drivers on that side very marginally off the track. As the centre drivers are insulated on both sides, there was no electrical feed at times, hence the problem. On changing the driver it fell to pieces! Sorry, for going on bit, but I hope my experience might help others. On the other hand, I have come across many more examples in China made models from all makes. Aidan Link to post Share on other sites More sharing options...
RJS1977 Posted June 6, 2014 Share Posted June 6, 2014 As long as they last the purchaser's lifetime that's long enough. I may well have another 50 years ahead of me yet....! Link to post Share on other sites More sharing options...
decauville1126 Posted June 7, 2014 Share Posted June 7, 2014 Mazak, also known as Zamak in some countries, has been around for a long time now. It is particularly useful in the automotive industry so I wonder if on this forum there are classic/vintage car enthusiasts with knowledge of degradation in their spheres of interest? Or is the problem mainly within the 'toy' industry, possibly indicating less-than-perfect quality control. There are also other areas where this alloy has been used over a long period but with what long-term stability effects? Link to post Share on other sites More sharing options...
34theletterbetweenB&D Posted June 7, 2014 Share Posted June 7, 2014 It swells, cracks and crumbles equally well in automotive, aviation, domestic and navy use in my direct experience. I have seen 1940 - 60 car and aviation parts failing, have a 1940 issue naval dirk split the length of the grip and a crosspiece crumbled off, and circa 1980 chromed bathroom furniture components disentegrating nicely. I wouldn't be remotely surprised if it eventually proves to have a half life of about two hundred years or so, when originally cast in the most stable formulations. Accelerators for failure such as contaminants introduced at casting, leaching, thermal cycling, vibration and loading, exposure to water and other liquids, will cause failure to occur earlier. Link to post Share on other sites More sharing options...
andyman7 Posted June 7, 2014 Author Share Posted June 7, 2014 It's very interesting, quite frankly if it lasts my lifetime that's OK...! What is clear is that if the mix is not pure, disintegration occurs within anything from 2-15 years - this would fit in with the known recent problems and the tales told here where the odd Triang casting has 'gone off'. I suppose the other end is indeed the question of how long a good quality casting lasts. I'm not aware of any general problem experienced in post war Dinky Toys so we can guess that 70 years or so is achievable with no loss of shape or integrity provided this is the case. Link to post Share on other sites More sharing options...
stewartingram Posted June 7, 2014 Share Posted June 7, 2014 Some time back, 2-3 years? - I picked up a Golden Arrow GT3 kit at Ally Pally. I then purchased off ebay, a tender drive Black 5, to provide the chassis for this, I also had some spare parts from a similar loco in stock. Somewhere in amongst this unfinished muddle, I discovered a few months back that 3 of the driving wjeels for one of the chassis had completely disintegrated. Fortunately enough spares are there to complete the loco build however (when I ger a Round Tuit to finish it off). Stewart Link to post Share on other sites More sharing options...
Ruffnut Thorston Posted June 7, 2014 Share Posted June 7, 2014 If the problem doesn't show up for several years I don't see how factory quality control would have found it? Ed The Railway Children Jinty casting was cast badly, and had not expanded due to deterioration, unlike the black one which has clearly expanded somewhat, after installation. Link to post Share on other sites More sharing options...
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