I am sure many colleagues on this forum, in addition to me, "dip" into other scales one way or another.
Back in August 2011 RMweb saw the beginning of a long running thread concerning the problem of disintegrating chassis on the Hornby class 31. This thread continues right up to the present day with several folk encountering the problem in their cherished models.
I understand the problem has been the material (mazak?) used in chassis block construction. Maybe a metallurgist on the forum could give some informed insight here.
Anyway, my reason for making this posting (as a fairly new member of the N gauge community) is to ask whether any such major issues have occurred amongst models in this scale.
Regards
Adrian
PS I seem to recall that Heljan had some "materials problem" some time back, but I don't have the details immediately to hand
I think I even posted on that thread. I'm a bit of a n00b to N-gauge but I've been reading this and other forums extensively and have yet to hear any tales of Mazak or exploding chassis. The main enemy here (primarily for Graham Farish stuff) is the dreaded split gear.
My dear old Farish class 31 was one of the first locos I bought Lord knows how many years ago and it has always been a lovely runner but I got it out of its box this week to find a gear has split. It's probably nowhere near as accurate as the new model due imminently but it's lasted me many a year.
The new 31s have landed, in the post, on its way to me..............
Quote from: Adrian on March 13, 2015, 03:55:16 PM
I understand the problem has been the material (mazak?) used in chassis block construction. Maybe a metallurgist on the forum could give some informed insight here.
Anyway, my reason for making this posting (as a fairly new member of the N gauge community) is to ask whether any such major issues have occurred amongst models in this scale.
Mazak rot hasn't afflicted any Farish or Dapol models to date (and hopefully never will).
The occasional the Peco Jubilee can suffer from bulging tender drive (on a minor scale though, usually fixable). Some fairly ancient Rivarossi motors can suffer from something similar in the motor magnets which seizes up the whole motor to a write off. I believe some early Atlas models can suffer from crumbling chassis blocks.
On the whole it's not something that's afflicted N gauge models and long may that continue!
Split gears on the other hand are common, but fortunately far easier to put right, and unlikely to write off a model in the way so many Hornby 31s (and others I believe) have been.
Cheers,
Alan
I've had Jubilee and Nord Pacific tenders from Rivarossi crumble, usually round the axle slots.
QuoteI understand the problem has been the material (mazak?) used in chassis block construction. Maybe a metallurgist on the forum could give some informed insight here.
Only to say mazak is generally an alloy of magnesium, aluminium, zinc and copper (known also by a few other different names). It's a step-up from the likes of whitemetal. I don't know the specifics other than reading forum threads and perhaps the odd mag article. I only read it was supposedly a batch (or few batches!) of a particular combination of the constituent parts. Hopefully nobody else used that particular mix, I've not heard it yet for GF / Dapol anyway but I have only been in n gauge for 5 years or so.
...Did I read somewhere there were also problems with it reacting with some form of paint or PVA type glue also?
Old Atlas chassis definitely crumble! I don't know what metal they're made from, but with age they start splitting and disintegrating. Two part metal glue has helped me rescue a couple - for how long I don't know!
Hi Adrian
Very interesting topic you bring up here.
My experience with Poole (UK) production Graham Farish is that there's nothing on an epidemic scale. Some identical chassis to me seem better than others and "appear" to have distorted over time. This is evidenced by the difficulty of achieving perfect shaft alignment through the bearings. I ponder the following;
a) they were just "bad" batches
b) they were "good" batches, but of an inferior compound
c) they've been somehow exposed to the elements that possibly distorted them in some way.
As I say, in my opinion nothing epidemic, but some chassis are definitely better than others (possibly due to distortion). Nothing has exploded on me (yet!)
Just my observations and experience.
Cheers
Dan
Quote from: Ozymandias on March 13, 2015, 05:54:00 PM
Two part metal glue has helped me rescue a couple - for how long I don't know!
I suspect there you've won the battle for now, but may ultimately lose the war as presumably it's still crumbling within :( . But if it keeps it going for another 5 or 10 years then all's good!
Cheers,
Alan
Quote from: Dr Al on March 13, 2015, 06:55:55 PM
Quote from: Ozymandias on March 13, 2015, 05:54:00 PM
Two part metal glue has helped me rescue a couple - for how long I don't know!
I suspect there you've won the battle for now, but may ultimately lose the war as presumably it's still crumbling within :( . But if it keeps it going for another 5 or 10 years then all's good!
Cheers,
Alan
How old are these crumbling Atlas chassis, just to out things into some kind of context? Yes, won the battle, but perhaps not the war. Visions if sticking your finger in a dam come to mind :scowl:
My first farish date from 1980 - 50+locos, steam and diesel - no problems regarding metal 'failure' to report.
As an aside - was using a 1981 class 47 last night, even the bulbs are original, all still fine.
Elmo
Quote from: Adrian on March 13, 2015, 03:55:16 PM
I am sure many colleagues on this forum, in addition to me, "dip" into other scales one way or another.
Back in August 2011 RMweb saw the beginning of a long running thread concerning the problem of disintegrating chassis on the Hornby class 31. This thread continues right up to the present day with several folk encountering the problem in their cherished models.
I understand the problem has been the material (mazak?) used in chassis block construction. Maybe a metallurgist on the forum could give some informed insight here.
Anyway, my reason for making this posting (as a fairly new member of the N gauge community) is to ask whether any such major issues have occurred amongst models in this scale.
Regards
Adrian
PS I seem to recall that Heljan had some "materials problem" some time back, but I don't have the details immediately to hand
Hi Adrain just to set matters straight "Mazak" is a brand name for "Zamak" which is a zink alloy comprising of elements of aluminium, magnesium, and copper. I would be very surprised to discover that this metal combusted under heat as I actually smelt the stuff!
Therefore I would be more inclined to think that maybe the chassis was made from Magnesium Alloy.
Regards
Mr Sprue
Some poor chap handed his heljan drs 47 into the shop for repair - the chassis had swollen and cracked the end of the body. Normal route for this is a replacement chassis from Heljan but howes (the uk dealers) are nil stock. So it was shortened and the body repaired - best to avoid buying any of these!
BUT it was nowhere near as bad as this chap on rmweb...
http://www.rmweb.co.uk/community/index.php?/topic/73731-heljan-47-chassis-expansion-can-anyone-beat-my-model/ (http://www.rmweb.co.uk/community/index.php?/topic/73731-heljan-47-chassis-expansion-can-anyone-beat-my-model/)
At least this is one thing we dont seem to suffer from as yet.
Russ
Not seen the contaminated mazak in N thankfully
There are some weird ones though - some Dapol 14xx and M7 locos the handrails expand over time and have to be replaced. Not sure what plastic they used but it's not a fitting problem or stretching - the parts genuinely grow bigger !
Quote from: RussellH on March 13, 2015, 08:11:09 PM
Some poor chap handed his heljan drs 47 into the shop for repair - the chassis had swollen and cracked the end of the body. Normal route for this is a replacement chassis from Heljan but howes (the uk dealers) are nil stock. So it was shortened and the body repaired - best to avoid buying any of these!
BUT it was nowhere near as bad as this chap on rmweb...
http://www.rmweb.co.uk/community/index.php?/topic/73731-heljan-47-chassis-expansion-can-anyone-beat-my-model/ (http://www.rmweb.co.uk/community/index.php?/topic/73731-heljan-47-chassis-expansion-can-anyone-beat-my-model/)
At least this is one thing we dont seem to suffer from as yet.
Russ
That's bonkers Russ!
"MAZAK" = UK brand name for a zinc-based alloy more commonly known as Zamak! i.e. Zinc, aluminium, magnesium, and copper.
For what it's worth Zamac (Z2) is the only metal that has similar density to human bone and is used for the construction of crash test dummies, if Zamak had expansion properties do you really think it would be used for these expensive tests?
Dave
You're familiar with Poole chassis I know. What are your thoughts on those, keeping their shape over time?
I'd echo elmo's earlier post that they are okay, but I have a few that I have my suspicions over. I'm not necessarily talking expansion, just some form of deformity. This could have been during manufacture mind, and not the result of later changes to the cast.
I can't remember if we concluded they were mazak too.
Cheers
Dan
Presumably muzak loses the aluminium and has uranium in it? :dunce: :confused2:
Quote from: DesertHound on March 13, 2015, 07:00:00 PM
How old are these crumbling Atlas chassis, just to out things into some kind of context?
Pretty old - of the order 30 years, though I don't know when the problems with them started manifesting themselves to owners - that's a bit before my involvement with N!
But similar aged Farish is still solid as a rock, so I'd be fairly confident in their longevity.
Cheers,
Alan
Quote from: DesertHound on March 13, 2015, 09:04:47 PM
I can't remember if we concluded they were mazak too.
They are Mazak - well, that's what was said and shown in the factory tour in Model Rail video 2 when they showed the ingots being melted down to cast the blocks.
Cheers,
Alan
Quote"MAZAK" = UK brand name for a zinc-based alloy more commonly known as Zamak! i.e. Zinc, aluminium, magnesium, and copper.
For what it's worth Zamac (Z2) is the only metal that has similar density to human bone and is used for the construction of crash test dummies, if Zamak had expansion properties do you really think it would be used for these expensive tests?
What an awful analogy! Use is poles part at either end of the spectrum.
Quote from: Dr Al on March 14, 2015, 12:02:34 AM
Quote from: DesertHound on March 13, 2015, 07:00:00 PM
How old are these crumbling Atlas chassis, just to out things into some kind of context?
Pretty old - of the order 30 years, though I don't know when the problems with them started manifesting themselves to owners - that's a bit before my involvement with N!
But similar aged Farish is still solid as a rock, so I'd be fairly confident in their longevity.
Cheers,
Alan
I'll go with that. I don't think we'll suddenly have an explosion (pardon the pun) of Farish chassis crumbling. The oldest ones see to have stood the test of time.
Quote from: Dr Al on March 13, 2015, 04:29:09 PM
Mazak rot hasn't afflicted any Farish or Dapol models to date (and hopefully never will).
The occasional the Peco Jubilee can suffer from bulging tender drive (on a minor scale though, usually fixable). Some fairly ancient Rivarossi motors can suffer from something similar in the motor magnets which seizes up the whole motor to a write off. I believe some early Atlas models can suffer from crumbling chassis blocks.
Both my Peco Jubilees went with the bulging cracked tender bodies. Similar aged and older Farish stored along side show no signs of any dimensional instability.
Early Farish do seem a different metal than the corroding Pecos based on cutting and filing over the years.
It seems to be down to impurities in the Zinc (possibly lead, google 'Zinc Pest').
I guess they either need to keep a better eye on their suppliers, or find out if they are doing something in the smelting which is causing the trouble.
I have one or two Farish diesel chassis (not more than that) which seem to have "blistered". By that I mean they have a bulge, a bit like a cist (sorry for the analogy) and I can only think that's down to an impurity.
Anyone with expert knowledge care to comment? Dave?
Dan
It is the Rivarossi SNCF 231 'Chapelon' that is perhaps the worst sufferer of Mazac decay. The expansion of the motor block cracks the tender body. Here is a classic example:
http://www.ebay.co.uk/itm/N-GAUGE-FRENCH-RIVAROSSI-LOCO-SPARES-REPAIR-2-6-4-15-/201257564696?pt=UK_Trains_Railway_Models&hash=item2edbe2ba18&nma=true&si=a7Dfu%252FOWEvRmZL0vobClKtHJ7mk%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557 (http://www.ebay.co.uk/itm/N-GAUGE-FRENCH-RIVAROSSI-LOCO-SPARES-REPAIR-2-6-4-15-/201257564696?pt=UK_Trains_Railway_Models&hash=item2edbe2ba18&nma=true&si=a7Dfu%252FOWEvRmZL0vobClKtHJ7mk%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557)
However, not all Chapelons suffer this effect. I have one which looks really good and runs very well, the equal to the Peco Jubilee from the same stable from about the same periof.
If you really want a good, reliable, Chapelon then save up for a Fulgurex one!
Mike
Quote from: RST on March 14, 2015, 01:54:30 AM
Quote"MAZAK" = UK brand name for a zinc-based alloy more commonly known as Zamak! i.e. Zinc, aluminium, magnesium, and copper.
For what it's worth Zamac (Z2) is the only metal that has similar density to human bone and is used for the construction of crash test dummies, if Zamak had expansion properties do you really think it would be used for these expensive tests?
What an awful analogy! Use is poles part at either end of the spectrum.
I can appreciate that your comment is probably based on electronic physics, but before the debate continues lets first use the correct name for the metal which is Zamak. The probable answer to this thread is not something scientifically elaberate, but as Luke Piewalker has already stated most likley to be zinc pest.
So to make things clear and simple those who have a collection of early models with zinc alloy chassis, storing them in an environment with high humidity runs a great risk of damage, but it doesn't stop there either! Sudden temperature changes could also start the process, so if you store your prize collection in the loft it's not a good idea.
As a precaution it would be prudent to examine your cherished oldies periodically, check the alloy chassis for pitting or blistering, its worth knowing that zink pest affected some batches of models probably upto around 2005.
Last of all lets not forget that Zinc is also used as a sacrificial anode to protect submerged metals below the water line on boats!
Quote from: DesertHound on March 14, 2015, 01:05:49 PM
I have one or two Farish diesel chassis (not more than that) which seem to have "blistered". By that I mean they have a bulge, a bit like a cist (sorry for the analogy) and I can only think that's down to an impurity.
Anyone with expert knowledge care to comment? Dave?
Dan
Dan damp or humid conditions friend!
This form of corrosion also affects 1950's Dinky Diecasts
Quote from: javlinfaw7 on March 15, 2015, 10:31:00 AM
This form of corrosion also affects 1950's Dinky Diecasts
Thats correct many serious collectors have shed a tear or two, especially when you see the price that some are sold for! :o
Very interesting guys. Dave, what are your thoughts on a Poole a Farish for the long run if stored correctly? Like others have noted, there's been no "mass outbreak" yet, so I'm assuming we're ok.
Cheers
Dan
Quote from: DesertHound on March 14, 2015, 01:05:49 PM
I have one or two Farish diesel chassis (not more than that) which seem to have "blistered".
Would be interesting to see a pic of this.
Cheers,
Alan
Quote from: Dr Al on March 15, 2015, 05:01:04 PM
Quote from: DesertHound on March 14, 2015, 01:05:49 PM
I have one or two Farish diesel chassis (not more than that) which seem to have "blistered".
Would be interesting to see a pic of this.
Cheers,
Alan
Sure. I won't be able to check until midweek. It might take some digging around as I can't remember which one/s it/they are but I'm sure I'll find something.
Cheers
Dan
Quote from: DesertHound on March 15, 2015, 03:56:17 PM
Very interesting guys. Dave, what are your thoughts on a Poole a Farish for the long run if stored correctly? Like others have noted, there's been no "mass outbreak" yet, so I'm assuming we're ok.
Cheers
Dan
I would assume Dan that these models ordinarily are stored in the natural environment of peoples homes, where temperatures are consistantly stable with minimal humidity. However as I've already suggested to you if storing these models in a collection for long periods then silaca beads or gel in an air tight container would be a good preventative measure to take.
Quote from: Dr Al on March 15, 2015, 05:01:04 PM
Quote from: DesertHound on March 14, 2015, 01:05:49 PM
I have one or two Farish diesel chassis (not more than that) which seem to have "blistered".
Would be interesting to see a pic of this.
Cheers,
Alan
Well I'm glad you asked. It appears to me that Minitrix have been shown up by Poole Farish for a change! I checked through my stock, unclip ping bodies, rummaging through the drawers ... nothing. I checked again, was I going crazy? Nothing.
Oh let's t that ONE Minitrix class 47 I've got. Here are the findings ...
[smg id=23081 type=preview align=center caption="image"]
[smg id=23082 type=preview align=center caption="image"]
Quote from: DesertHound on March 19, 2015, 12:42:45 PM
Well I'm glad you asked. It appears to me that Minitrix have been shown up by Poole Farish for a change! I checked through my stock, unclip ping bodies, rummaging through the drawers ... nothing. I checked again, was I going crazy? Nothing.
That doesn't surprise me - I've never seen any Farish that's obviously exhibited a problem, even the most ancient of stuff, which is a good thing.
Quote from: DesertHound on March 19, 2015, 12:42:45 PM
[smg id=23081 type=preview align=center caption="image"]
Those look like the little inboard weight inserts that have bulged, rather than the main mazak chassis block - I think the inserts are a different material (it's softer certainly), but specifically what it is I'm not sure.
Regards,
Alan
Yes, you're right, it's not the main block. I remember now when I dismantled it for a service (only have one) those weight inserts were quite soft, possibly lead.
Cheers
Dan
Yes, I was under the impression that they had at least some lead content, and this kind of thing is similar to what I've seen on some Peco Jubilee tender blocks. I suspect filing back the bumps would be good enough to ensure they don't start pressing out or bowing the bodyshell - you might even get away with just removing them completely.
Cheers,
Alan
Quote from: DesertHound on March 19, 2015, 02:42:51 PM
Yes, you're right, it's not the main block. I remember now when I dismantled it for a service (only have one) those weight inserts were quite soft, possibly lead.
Cheers
Dan
I'll keep an eye on it. Yes, issue could be that it affects the body (bows out etc.) So far it seems "okay" and makes for a tighter body - will look to see if it's bowing it in any way.
Good that it was a Minitrix and not a Farish - phew! :doh:
Come to think if it now, I think that must be the only one with this problem. Thought I might have a couple, but given it's on my only Trix, I think my Farish chassis are "okay".
Correct me if I'm wrong, but if there's any issue with Farish (not necessarily widespread) it's with the chassis distorting slightly (laying it on a piece of glass can identify tis).
Cheers
Dan
I've seen distorted chassis, and I've heard that in part blamed on children mishandling them (leaning on them to stand up etc). I've not had any showing signs of zinc problems thankfully.
My lima deltic is all lumpy and bulging - but that's the shape it was made :bounce:
Quote from: EtchedPixels on March 19, 2015, 03:28:53 PM
My lima deltic is all lumpy and bulging - but that's the shape it was made :bounce:
:laughabovepost:
oops...
thought it was referring to Bullieds West Countries and Merchant navies!!!!
Well I hope I don't get any unusual looking lumps appearing in my collection as there is about 40 kilos of the stuff! :)
(http://i1347.photobucket.com/albums/p713/MrSprue/NGF%20Miscellaneous/20150319_162221_zpssrzqdwnp.jpg)
Quote from: DesertHound on March 19, 2015, 03:00:59 PM
Correct me if I'm wrong, but if there's any issue with Farish (not necessarily widespread) it's with the chassis distorting slightly (laying it on a piece of glass can identify tis).
I've seen a few 94xx chassis that weren't that straight, but I doubt this is a distorting issue, rather that it's been warped by previous owners pressing on them, overtightening screws or attaching to kitbuilt bodies that put force on the chassis if the screws are again overtightened.
For diesels I'd suspect there's a good chance they weren't made perfect in the first place if they aren't straight!
Cheers,
Alan