Hornby corroded class 31 chassis

[lochlongside]

If there was mileage in it for a spares supplier, an alternative route to cost out would be an outfit with the capability to bring in scanned and cast replicas at a low price. I am thinking of the GBL items, which must have been got very cheaply for the retail price they sold at. Their castings based on scanned RTR are definitely in the frame for replication of a chassis block, if the piece under the A2 is anything to go by.

Much as I would like a solution to this problem I  find myself much more in agreement with Graham456 on this. This approach will require deep pockets.

I am no expert in machining but looking at the Service sheet the R2413 / R2421 chassis casting is a pretty complex shape which probably explains why it is a casting. This together with precision tapped screwholes etc for the bits fastened on is not going to be cheap to machine from scratch.

Peters Spares has machined what is by comparison a relatively simple small spare for the T9 motor mount (PS61) and that is well over £9. A brass replacement of the chassis block plus the two screw -on end plates (which in case of my faulty loco have also degraded) from a non-Hornby source is probably going to be well over £50 for each faulty loco. Considering that I and presumably several others got these locos from the shifters for around £69 (still got price tag on my box) this solution is not really going to be cost effective for the majority of us.

I await with academic interest to see the next move in this saga and if it comes in at under about £28 then I would be a delighted convert but I think that at my age my £50+ can more profitably (and quickly) be invested in something new and in the meanwhile I will tinker with the remains .

[Foden]

I have one of the rotters, R2421. It's been 'in store' in it's original box, and in a dry location for years. On inspection it still appears to be in fine condition, and still works as it should.

As I'm quite fond of the model, I'd like to swap the body onto a non rotten chassis before any damage is done. Is this simply a case of finding a later non rotten example, and then just swapping the body over, and then problem solved?

[34theletterbetweenB&D]

I have one of the rotters, R2421. It's been 'in store' in it's original box, and in a dry location for years. On inspection it still appears to be in fine condition, and still works as it should...

I don't know of any certain information, whether any of these were produced with castings from a good batch of alloy? Not knowing that, it is possible you may not have a problem at all. My rule of thumb is that ten years trouble free, probably means no Mazak rot.

 

Let's be very cautious though: to avoid potential  damage to the body, best to separate this from the mechanism if it is 'out of sight' in long term storage. Should expansion of the casting due to Mazak rot occur, it can be pretty destructive of the body shell.

 

As I'm quite fond of the model, I'd like to swap the body onto a non rotten chassis before any damage is done. Is this simply a case of finding a later non rotten example, and then just swapping the body over, and then problem solved?

 

If the problem arises, that would do it; but unless you are prepared to swap components over, you will need a later model with the same light fit, and any other matching detail on the mechanism.

[Foden]

I don't know of any certain information, whether any of these were produced with castings from a good batch of alloy? Not knowing that, it is possible you may not have a problem at all. My rule of thumb is that ten years trouble free, probably means no Mazak rot.

 

Let's be very cautious though: to avoid potential  damage to the body, best to separate this from the mechanism if it is 'out of sight' in long term storage. Should expansion of the casting due to Mazak rot occur, it can be pretty destructive of the body shell.

 

 

If the problem arises, that would do it; but unless you are prepared to swap components over, you will need a later model with the same light fit, and any other matching detail on the mechanism.

Sound advice.

 

I've still not yet pulled the body off the chassis, as I have other items ongoing on my work bench, but I'll defiinitely make it a priority before putting it back.

 

I've no issue swapping over components onto a later chassis. Infact I've just bought a later model to re-spray, and if I make a complete hash of the respray, voila, spare chassis!

[Roy Langridge]

I have one of the rotters, R2421. It's been 'in store' in it's original box, and in a dry location for years. On inspection it still appears to be in fine condition, and still works as it should.

 

As I'm quite fond of the model, I'd like to swap the body onto a non rotten chassis before any damage is done. Is this simply a case of finding a later non rotten example, and then just swapping the body over, and then problem solved?

If you do buy just a full running chassis from somewhere like ebay, just be careful to watch for the different versions for skinhead / headcode box variants.

 

Roy

[adb968008]

Much as I would like a solution to this problem I  find myself much more in agreement with Graham456 on this. This approach will require deep pockets.

I am no expert in machining but looking at the Service sheet the R2413 / R2421 chassis casting is a pretty complex shape which probably explains why it is a casting. This together with precision tapped screwholes etc for the bits fastened on is not going to be cheap to machine from scratch.

Peters Spares has machined what is by comparison a relatively simple small spare for the T9 motor mount (PS61) and that is well over £9. A brass replacement of the chassis block plus the two screw -on end plates (which in case of my faulty loco have also degraded) from a non-Hornby source is probably going to be well over £50 for each faulty loco. Considering that I and presumably several others got these locos from the shifters for around £69 (still got price tag on my box) this solution is not really going to be cost effective for the majority of us.

I await with academic interest to see the next move in this saga and if it comes in at under about £28 then I would be a delighted convert but I think that at my age my £50+ can more profitably (and quickly) be invested in something new and in the meanwhile I will tinker with the remains .

Maybe someone could come up with a less complex chassis design to stick the bits on.

If they did the same with the Lima 50 (to stick 37 bogies under instead) it would bring it up a treat.

[34theletterbetweenB&D]

Maybe someone could come up with a less complex chassis design to stick the bits on...

 

 

There is no fundamental obstacle preventing you from being that 'someone'. I have the 'much, much less complex' design in my back pocket, and you are welcome to it.

 

Obtain a brass extrusion U channel, external width 31mm/1.25" height of sides 25mm/1", wall thickness 1.5 mm/ sixteenth inch, 152mm/6" long. User to drill holes and make cut outs as required using the supplied template, to mount motor and bogies. (User adds all other doodads and fixings as required to mount body, external detail and internal components of choice.)

 

The devil as ever is in the detail. For every person like me who thinks that mounting the motor and bogies is job done, there will be a hundred (larger numbers possible)  wanting tapped holes to attach this, shapings to clear that, lugs to accept yonder items, and channels to guide wiring, all correct for the particular version they own...

[Izzy]

I'm amazed to see - perhaps I shouldn't be - that Hattons have secondhand 31's & 50's with chassis problems either listed or obvious from the descriptions, loose bufferbeams, bodies cracked etc, and still asking £100+ for them.

 

Izzy

[rob D2]

I don't think any of those have been ID with Duff mazak, so I think it'll be ok

[rob D2]

It is a good idea to remove the bodies ,

But it's always a pain in the arse with screws hidden under bogie sides and can interiors that fall out and are hard to get to line up on the return

[Jamiel]

I'm amazed to see - perhaps I shouldn't be - that Hattons have secondhand 31's & 50's with chassis problems either listed or obvious from the descriptions, loose bufferbeams, bodies cracked etc, and still asking £100+ for them.

 

Izzy

They are not the only ones, another well known supplier has 31s for sale on Ebay with bodies damaged and ends cracked off.

 

It is a pity that these sellers continue to sell them, not only as they are passing on goods that will decay further to unknowing customers, but it would be better for us all if they returned them to Hornby and asked for them to be fixed, as they have the retail power to push Hornby harder than any individual can.

 

I would be tempted to say that if someone could build an etched frame to make up, bend and solder to fit the Hornby components it would help, but I suspect that the number of 31 owners who would want to go thorough the fuss of all that is a far too small group to justify it. For me it would be a great, and more cost effective solution, but I am probably in a minority on that.

[37114]

They are not the only ones, another well known supplier has 31s for sale on Ebay with bodies damaged and ends cracked off.

 

It is a pity that these sellers continue to sell them, not only as they are passing on goods that will decay further to unknowing customers, but it would be better for us all if they returned them to Hornby and asked for them to be fixed, as they have the retail power to push Hornby harder than any individual can.

 

I for one am glad that the damaged ones are for sale on ebay etc, as per my earlier post they can be picked up cheaply and the mechanisms put in the (IMHO) better looking Lima shell.

 

I imagine that Hornby have stopped repairing them as they are not getting any duff ones fed back into them from either individuals or retailers in sufficient quantities for Hornby to justify offering the option to repair them anymore. It is perhaps not unreasonable for Hornby to draw a line and say "No more, we have given customers long enough to return them, we offered repair for a reasonable amount of time and communicated the option to return widely through the trade media etc so it is fair to stop the repairs". As an example I would not expect to be able to take a rusted out Lancia Beta back to your Fiat dealer now even though at some point in the past Lancia put there hands up and said they didn't properly rust proof the cars and tried to rectify the situation in the 1980's?

[Pandora]

I have been stripping down my three "zinc-pested" Hornby class 31 diesels today.  The bodies shell  cracks or splits are below the cab door and can be repaired,  a back to back comparison between  Lima  and  Hornby shell is  an educational experience,  other than the difference in length, (Lima is 3mm shorter) there is little to choose between the two in look and detail

[Izzy]

I have been stripping down my three "zinc-pested" Hornby class 31 diesels today.  The bodies shell  cracks or splits are below the cab door and can be repaired,  a back to back comparison between  Lima  and  Hornby shell is  an educational experience,  other than the difference in length, (Lima is 3mm shorter) there is little to choose between the two in look and detail

 

Yes, it's funny to discover that despite being shorter, the Lima bogies are set at the correct distance apart but with the wheelbase being wrong at 54mm rather than 56mm. I presume this was because they originally used the same motor bogie as the 37 for which it is correct. Does mean however that you can't easily mix & match between the exLima and Hornby versions.

 

Izzy

[Pandora]

Thinking through my ideas to salvage my zinc-pested Hornby 31 locos, did not mention before that the  body screw pillars in the roof of the shell  have split,  the bodies can be saved by glueing the cracks and also making reinforcing  collars for the pillars from tube or washers.

 

I intend to cut off the ends of the chassis  block forward of the cab bulkheads to give a offcuts which includes  the metal buffer beam,  I think I can trim back the defective metal of the offcut  leaving behind only the metal buffer beam  which I intend to  glue it into the shell.

Edited August 24, 2017 by Pandora

[Hroth]

The only way to salvage a solid Mazak casting with Zinc pest is to ditch it.  Cutting off the affected parts only means you're left with a lump of metal that has the same metallurgical content as the currently affected bits - there's no guarantee that the rest isn't going to start disintegrating sooner rather than later.

 

Perhaps the only way forward is to keep the mechanicals and try to replicate the style of a lima chassis in brass....  Its just a shaped box, sized to fit the body, not as complicated as a steam loco chassis!  I've a full-fat 31, which is not in the pest-infected list, yet.  If anything does happen to it, I'll probably give that route a go.

[Pandora]

The only way to salvage a solid Mazak casting with Zinc pest is to ditch it.  Cutting off the affected parts only means you're left with a lump of metal that has the same metallurgical content as the currently affected bits - there's no guarantee that the rest isn't going to start disintegrating sooner rather than later.

.

Good point, I would ditch the casting if I could buy a replacement part,  but the main structures of the original  blocks show  no sign of  expansion or failure after 12 years, other than the  thin "weak" extensions to the cab area, they are mildly  warped as opposed to the severe breaking free/shattering  as exampled by images on Rmweb.  I think it is worth risking persisting with the fix,as  being in my 60s,  who or which  is most likely to suffer disintegration requiring the fabrication of a certain  "shaped-box" , "sized to fit the body"

Edited August 24, 2017 by Pandora

[Lenny]

is this a metal disease, and is it able to be transmitted to other metals or similar locos , sorry for being dumb on this

 

Richard 

[pheaton]

is this a metal disease, and is it able to be transmitted to other metals or similar locos , sorry for being dumb on this

 

Richard 

No

 

its a manufacturing defect, caused by impurities making there way into the original alloy used for casting.

 

As an aside if anyone has any intact cab floor plates that screw on the the bufferbeams from an affected chassis drop me a pm, im in the market for a couple of them

Edited August 24, 2017 by pheaton

[pheaton]

Good point, I would ditch the casting if I could buy a replacement part,  but the main structures of the original  blocks show  no sign of  expansion or failure after 12 years, other than the  thin "weak" extensions to the cab area, they are mildly  warped as opposed to the severe breaking free/shattering  as exampled by images on Rmweb.  I think it is worth risking persisting with the fix,as  being in my 60s,  who or which  is most likely to suffer disintegration requiring the fabrication of a certain  "shaped-box"?

Its been seen in 50s as far as i can tell though its only affects the cab floor plates and not the actual main casting. Its not been seen as far as i know in 56s or 60s.

 

The simple way to tell if your model is likely to be affected even before  damage has occurred is to pop the body-shell off and look carefully at the sides of the main chassis casting if the model is affected you will see something that looks a bit like a stain, normally about an inch or so across if you reflect light off the chassis it will show up easier its more matt than the chassis surface, and looks different from casting marks (as it will have an even consistency) which would be a collection of pits or raised bumps. If you look under a magnifying glass it looks like a rough surface and this is where the alloy has started to oxidise.

 

if this stain is present the absolute way to confirm it is to put gentle pressure on the cab ends, if they snap off this is an affected model the cab ends of an unaffected model will require considerable force to break them (trust me ive tried ) and no i dont take any responsibility for you trying this

Edited August 24, 2017 by pheaton

[Pandora]

is this a metal disease, and is it able to be transmitted to other metals or similar locos , sorry for being dumb on this

 

Richard 

Here is a wikipaedia link  "zinc pest"

 

https://en.wikipedia.org/wiki/Zinc_pest

[Krieghoff]

I have just opened up my class 31 31110 after a period of years boxed up to find a small crack in the bodyshell at the front end. On taking the shell off the chassis appears to be OK but the metal cab floor plates are all bowed. On taking these off one disintegrated completely but the other is just really bowed (evidenced by placing it on a flat surface. My other two seem to be unnafected (raifreight red stripe 31 105 and Sub Sector 31 296). I have taken the bodies off and again the chassis don't seem to be affected.

 

I too contacted Hornby recently to be told 'no spares available and no chassis blocks either'

 

 

Personally I think that this is absolutely appalling if im honest. Hornby over the past few years IMHO don't seem to have the edge in relation to quality. Some may disagree but you just never used to get this type of issue with their loco's. The price we pay as modellers today isn't cheap and problems like this are not acceptable.

 

Hornby need to re-run some of these older models with new batch castings and at least give modellers a chance to purchase decent models that have a better degree of longevity built in.

 

Come on Hornby, get some more chassis sorted out so we can buy them and fit them ourselves.

Edited September 10, 2017 by Krieghoff

[newbryford]

An extreme case with the classic example of D5512.

https://www.ebay.co.uk/itm/Hornby-R2420-BR-Co-Co-Diesel-Electric-Class-31-D5512-Locomotive-BOXED/183002837876?hash=item2a9bd1b374:g:vVIAAOSw7p5aUO6l

 

Credit to the seller for the photos....

 

Cheers,

Mick

[Classsix T]

Melted bogie moulding too, not pretty.

 

C6T.

[richierich]

Much as I would like a solution to this problem I  find myself much more in agreement with Graham456 on this. This approach will require deep pockets.

I am no expert in machining but looking at the Service sheet the R2413 / R2421 chassis casting is a pretty complex shape which probably explains why it is a casting. This together with precision tapped screwholes etc for the bits fastened on is not going to be cheap to machine from scratch.

Peters Spares has machined what is by comparison a relatively simple small spare for the T9 motor mount (PS61) and that is well over £9. A brass replacement of the chassis block plus the two screw -on end plates (which in case of my faulty loco have also degraded) from a non-Hornby source is probably going to be well over £50 for each faulty loco. Considering that I and presumably several others got these locos from the shifters for around £69 (still got price tag on my box) this solution is not really going to be cost effective for the majority of us.

I await with academic interest to see the next move in this saga and if it comes in at under about £28 then I would be a delighted convert but I think that at my age my £50+ can more profitably (and quickly) be invested in something new and in the meanwhile I will tinker with the remains .

Why not cast new chassis blocks in aluminium? Use to have facilities for casting aluminium at school and college. Then it would be just a matter of cleaning up the casting.