Dublo N2 Resurrection (Hopefully)

[PatB]

An impulse buy on Ebay has seen me become the proud(?) owner of a Dublo N2 and two suburban coaches in what can best be described as "distressed" condition. Still, they were cheap.

 

First up is the N2. here it is. The more sensitive may wish to look away now.

 

 

As you can see, it's pretty well worn. It shows every sign of several decades rattling around in toyboxes with a few divots out of the alloy to go with the missing paint. Damp seems to have played some part in its deterioration too, with dusty white deposits on the pony wheels. Couplings are badly twisted but should straighten up OK. On the plus side, it's got all its buffers, steps and guard irons so it should scrub up nicely.

 

First job is to get the body off and into the paint stripper. The paint stripper I'm using directs users to wear "suitable protective clothing". What that actually means I'm not sure, as the evil stuff ate rapidly through gloves made of at least three different materials as I was working . After the first coat it looked like this.

 

 

It's gone back into the bath for the night to get the rest off. We'll see what it looks like tomorrow.

 

[PatB]

Moving on to the chassis, an initial assessment shows the corrosion on the wheels as previously noted, a missing upper bearing locknut, a rusty pole-piece on the motor, no springing on the pickup shoes, near zero magnet strength and a very strong smell of escaped magic smoke from the commutator.

 

 

Application of 12V between chassis and pickup shoes resulted in the motor struggling round for part of a turn and then stopping with every sign of a dead short. Rewind time methinks.

[Prometheus]

Out of interest, what paint stripper did you use ?

 

Thanks

 

Tony

[PatB]

Out of interest, what paint stripper did you use ?

 

Thanks

 

Tony

 

Can't remember the brand and am now away from the shed so I can't check. It's just a generic, snot textured one from the local paint shop, which I had available from an unrelated project. The second bath (which it's in at the moment) is Citristrip, which I find to be marginally less frightening.

[Il Grifone]

The poor darling doesn't look too happy. It looks like the last owner fitted the front coupling upside down somehow! The pony wheels might clean up, but the white crud keeps reappearing, I find. Luckily replacements are not hard to find.

 

The paint stripper looks like good stuff. Dublo paint is notoriously hard to shift!

 

Good Luck with the project

[PatB]

Further to the paint stripper queries, this is the stuff I used for  the first go. I'd have used it for the second try too, but my inability to find any gloves I can actually work in that will keep the stuff out rather limits its usefulness.

[locomad]

The poor darling doesn't look too happy. It looks like the last owner fitted the front coupling upside down somehow! The pony wheels might clean up, but the white crud keeps reappearing, I find. Luckily replacements are not hard to find.

 

The paint stripper looks like good stuff. Dublo paint is notoriously hard to shift!

 

Good Luck with the project

Try grit blasting, been using this method over last 15 years, you can pick up a cheap grit blast gun for £8, home made metal box, use fine grit, crushed wallnut shells are the best used in jewellery industry for cleaning gold, I have even used fine sand off the beach. Course you need a compresser but again they are cheap and you don't need a powerfull one for fine small work

 

Certain strippers can eat into the base metal almost impossible to remove, they eat into the casting speeding up the mancik rot, I've a few bodies that someone repainted just cumble on us years later, so suspect the strippers have caused the problem, I know certain oven cleaners warn you of this problem

[PatB]

I'd imagine that anything caustic used on an alloy with any aluminium content would certainly have the potential to cause problems. I've also experienced apparent degradation of old, mazak(ish) carburettor parts which were forgotten whilst in a jar of acetone, so I tend towards cautious when mixing chemicals with old metal. On this occasion, however, given the cheapness and lack of historical importance of the subject, combined with my inherent laziness and lack of abrasive blasting gear, I've decided to chance it. The cleaned shell will be receiving a very thorough hot rinse before painting which I hope will be sufficient.

[Il Grifone]

Reading the material safety data sheet for the paint stripper was rather frightening. It's probably not available in H & S conscious Britain! Nitromors our 'favourite' brand seems to have lost its effectiveness..... An alternative brand I tried was useless.

 

In my youth, (a long time ago!) I stripped my 'Bristol Castle' with hot caustic soda (I wouldn't now!). It was very effective and seems to have had no ill effects. She's still OK fifty years on, having been repainted yet again about thirty years ago.

 

I wouldn't say that a Dublo N2 was without "Historical importance". I consider it an iconic model of the 'Every home should have one (or more)'    variety. It was in almost continuous production for over fifty years. I won't say how many I have...

 

I've just being making a rear chassis mounting for a Wrenn version - the proper part will be difficult to obtain!  Likewise the rear bogie, which is different from the Dublo type (I missed one on eBay   ). For now she has a Hornby one from the spares box - I've no idea what it's really for. She needed repainting (originally LNER green but had received a coat of tar at some time). At the moment she's plain black. Possibly 'BRITISH RAILWAYS' and E95xx?

[PatB]

I wouldn't say that a Dublo N2 was without "Historical importance". I consider it an iconic model of the 'Every home should have one (or more)'    variety. It was in almost continuous production for over fifty years. I won't say how many I have...

 

 

 

I was thinking more that the world is unlikely to run short of knackered BR black N2s any time soon, and so my individual example is more or less expendable, rather than decrying the model itself .

 

As for the availability of dangerous substances, you don't know what "risk aversion" is until you've met a few Australians .

[Golden Fleece 30]

I always use Caustic Soda, very carefully, AND add crystals to the water not the other way around.  Do this outside and then a lot of hot water with CIF cream and more hot water to rinse off.  Sometimes I also finish off using a small brass wire brush in a Dremel to go over the castings.  No problems so far after about 10 years of using the soda (I hope that does not jinx me now).

 

Here is one of my 0-6-2's I did for something different.  Normally I use replica varnish fix transfers but this time I wanted fully lined with BRITISH RAILWAYS on the sides.  I do not think any were ever done like this and a friend made me some self adhesive overlays with consecutive numbers.  The other loco was either 69490 or 69492.

 

Garry

[Prometheus]

Now that does pass muster.

 

Tony

[Il Grifone]

Now I have to do mine!

 

I think the decision to use LNWR lining (You can tell R.A. Riddles was a Crewe man!) followed the introduction of the anorexic lion, but it looks great. I was going to chicken out of any lining on mine....

 

I was going to do another one as GNR 4744*. She is fitted with condensing pipes, so this involves making them, ordering a set of the white metal ones available on eBay , or ignoring it (the latter has most Grifone appeal (lazy), especially since lining is essential here - I should have some left over from my BR blue 'Coronation' **)

 

* This has got as far as being painted green. Since there only ever was one LNER green N2, I understand (She wasn't 9596 either - 9520 IIRC) something different is called for - 9520 had condensing pipes too. 

 

** & this has got as far as being painted blue.....  (Vallejo Prussian Blue)

[Golden Fleece 30]

Here are 5 0-6-2 repaints.  The top two are the older versions with solid pony truck wheels as opposed to the spoked ones and the bodies are fitted with Nickel buffers instead of cast ones.  The middle two are what I mentioned earlier with overlays.  The bottom one is a repaint using varnish fix transfers which I do prefer.

 

Here is a clip of the top two in action without any modified Dublo stock being pulled.

 

[PatB]

I always use Caustic Soda, very carefully, AND add crystals to the water not the other way around.  Do this outside and then a lot of hot water with CIF cream and more hot water to rinse off.  Sometimes I also finish off using a small brass wire brush in a Dremel to go over the castings.  No problems so far after about 10 years of using the soda (I hope that does not jinx me now).

 

Here is one of my 0-6-2's I did for something different.  Normally I use replica varnish fix transfers but this time I wanted fully lined with BRITISH RAILWAYS on the sides.  I do not think any were ever done like this and a friend made me some self adhesive overlays with consecutive numbers.  The other loco was either 69490 or 69492.

 

Garry

 

Very nice.

 

I am interested to note, though, that the body casting looks a little "lumpy" above the front splasher. I've been worrying that mine has similar lumps in a few areas and that it might denote some underlying corrosion problem in the mazak but if such issues extend to other examples I'll put it down to worn tooling at the factory. I've taken a few of the more prominent blemishes off the tank and bunker sides with 400 grit but there are a couple on the boiler/firebox/tank top joint that I just can't get to with anything I can sensibly remove enough material with. Hopefully, once it's painted and lined, it won't show too much. No more than the quite noticeable mould lines anyway .

 

[Golden Fleece 30]

Hi Pat,  on the 0-6-2 there are quite a few "lumps" and like you I thought about the Mazak issue but straight away looked at a few more and a lot have them in the same place, others don't.  This as you say maybe due to the tooling getting worn.  One noticeable line is a fine one going around part of the smokebox on a few of mine near the front.  These can be seen on the two locos facing the right. Sometimes the fault is a recess as opposed to a ridge and can be seen on 69491 between the tank front and the dome going over the boiler.  This is not on the LMS version.

[PatB]

Well, a night in Citristrip, followed by a further bath in caustic soda based oven cleaner, a bit of work with 400 grit to knock off some of the more major blemishes in the casting and, finally, a scrub in Jif with a toothbrush left things looking quite a bit better.

 

 

A quick spritz with my favourite (read cheapest) etch primer and the old girl's looking really quite presentable.

 

 

Apologies for the dodgy photos. The power was off and the weather was awful so lighting within and without the workshop was rather dim, resulting in a slow "shutter" and a big aperture.

 

Something I do find nice about this resto is that I don't have to worry about scrubbing detaching tiny parts which then escape down the sink. Anything falling off a Dublo loco probably indicates that an airliner has crashed on your house .

 

 

[Il Grifone]

Very nice.

 

I am interested to note, though, that the body casting looks a little "lumpy" above the front splasher. I've been worrying that mine has similar lumps in a few areas and that it might denote some underlying corrosion problem in the mazak but if such issues extend to other examples I'll put it down to worn tooling at the factory. I've taken a few of the more prominent blemishes off the tank and bunker sides with 400 grit but there are a couple on the boiler/firebox/tank top joint that I just can't get to with anything I can sensibly remove enough material with. Hopefully, once it's painted and lined, it won't show too much. No more than the quite noticeable mould lines anyway .

 

Most Dublo castings seem to have these. I think they are some sort of moulding fault rather than corrosion, though it could possibly be a reaction to damp?

[Golden Fleece 30]

Most Dublo castings seem to have these. I think they are some sort of moulding fault rather than corrosion, though it could possibly be a reaction to damp?

 

I agree with you David about a casting fault as a lot of similar locos have similar "lumps" in the same place.  A lot of A4's have a small thin raised line 3 or 4mm long on one of the cab sides.  I don't say EVERY casting as some are cleaner than others and to me these could be early ones from the mould, or, later ones after the mould has been redone for various reasons.

 

Garry

[PatB]

I haven't been posting much as the restoration has been proceeding slowly, fitted into the odd ten minutes here and there between work for my "proper" job and the camera has never been convenient at a suitable point for photography.

 

Now, however, the bodywork is finished and I made a point of recording the completed work.

 

 

After the etch primer, I applied three coats of rattle-can satin black and touched in the buffer beams in red and the safety valves, whistle and makers plates in brass. Buffer heads,  handrails and smokebox dart were picked out in silver. Lining and numbering was done with self adhesive transfers off Ebay which turned out surprisingly well.  Then a couple of coats of gloss lacquer, because it was what I had, followed by refitting the handrails.

 

I'm certainly not going to claim perfection, or any kind of authenticity but, considering what I started with, I'm pretty chuffed with how it's turned out. I wouldn't have used gloss on anything purporting to be a scale model but, for a toy or, in this case, something intended for a yet (or maybe never) to be built garden railway, it seems entirely appropriate. I might need to have another go at those buffer beams too, but, for now, I think it will do.

 

 

[PatB]

I had the opportunity to have a look at the chassis tonight. No photos, i'm afraid, as the camera is 200 km away until tomorrow afternoon, but I'll describe my observations.

 

As noted before, I could carve a block of wood to the shape of the magnet and still have something with more magnetism in it than what's fitted at the moment, so I had no qualms aout removing the pole pieces and the magnet. I've got some neodymiums of suitable size on the slow boat from Shanghai, so knackering the original isn't too much of an issue.

 

I also pulled out the brushes and found both them and their springs to be surprisingly good. In conjunction with relatively unworn pickup spoons, I suspect that this loco, though old and abused, may not have done all that much mileage.

 

With the brushes and pole pieces removed I unscrewed  the locknutless upper bearing and wiggled the armature out. After scraping quite a lot of gack out of the commutator slots I applied the multimeter and, allowing for a zero error on the meter, got a reading of 5 Ohms between each pair of segments. I have to admit I'm surprised as I'd convinced myself that the windings were toast. The reading seems lower than I've seen noted in postings on the subject on RMWeb, but corresponds with the numbers mentioned in one of Mr Dodd's videos as being good, so I might give it a go as-is, before driving myself mad trying to rewind it.

 

Having pulled out the armature I was able to feel how stiffly the wheels turned. Quite stiffly and with a distinct tight spot like a quartering fault (although I can't really see how it could actually be one). I can see a slight kink in one of the rods but it doesn't look like enough to cause a problem, so I hope that it's  all down to ancient grot in the bearings. Does anyone have any tips on cleaning the axle bearings properly before relubing? I was thinking of putting the whole thing (minus motor and pickups of course) in a bath of something like meths and rotating the wheels for a while. On the other hand, I could take the wheels off but, given their semipermanent nature, that's something I was hoping to avoid.

 

Moving on to the pickups, I find myself slightly puzzled as my pickup assembly appears to contain a small but obviously purpose made washer (more a collar really) that doesn't appear on either the Dublo service sheet (as downloaded from Mainly Trains) or on Ron Dodd's video on the subject. It's circular and nicely countersunk on one side, apparently corresponding to either the head of the retaining screw or the indent in the pickup housing that accommodates the head of the retaining screw. I can't tell which, because it fell out unexpectedly and I didn't see where it came from. For now I've put it inside the housing, under the spring, where it seems to serve the purpose of spacing the spring away from the pickup housing and reducing pressure on the spoons.

 

Finally, the front coupling assembly seems to be a bit of a mess. Can anyone point me at a good close-up photo of a good assembly so that I can see how it's all supposed to work? I think it's all there but it's  suffered a certain amount of corrosion and a considerably greater amount of bodgery so I don't really have anywhere to start from in sorting it out.

 

So, in summary, a thorough cleaning and a new magnet should get me some considerable way to a running locomotive. In reality, on the large roundy-roundy where I envisage using this engine, a front coupling is of somewhat secondary importance. Everything else seems eminently sortable.

 

I just wish those magnets would hurry up and arrive so I can test it properly...

[Il Grifone]

Meths will work but I always use paint thinners (white spirit or similar). Strip the chassis to basics and then a good soak (Just brush it on generously) and then scrub the muck off with an old toothbrush, using a mild detergent and then plenty of water. By this time the wheels should turn freely. Do the armature bearings as well - take care not to lose the ball bearings - they shouldn't come out, but....

It's unlikely that the quartering is out  (the axles are splined and the wheels can't shift), but a slight bend in one or both coupling rods will cause a tight spot. (I've just had this problem with a Gaiety chassis. These are are not nearly as well engineered as Dublo, but it's OK now.)

 

I'll post a picture of the coupling later, unless someone beats me to it.

[Golden Fleece 30]

The washer you are referring to is a spacer to keep the phosphor bronze spring in the correct place due to the folded sides of the holder.  Sometimes (more modern ones I think) have a square spacer which was probably cheaper to produce.

 

Garry

[Il Grifone]

As promised here are the pictures (the first is rather cr soft - I'll try and repost - A nasty dripping type noise requires my attention )

 

 

 

 

 

 

The later washer* is a blank Meccano nut. Obviously a normal threaded one will do as a replacement. It fits above the spring and below the insulator 11548. Earlier springs consist of a piece of wire. IIRC the assembly is the same, but I would have to check. (The service sheets are for 1960s production. AFAIK for earlier items no sheets are available. Differences are minor - waxy capacitors and metal couplings mainly. There was a change in gear ratio around 1954 and pre-1949 a different chassis casting was used fitted with a horseshoe magnet.

 

*11299 Distance piece

[PatB]

Thank you gentlemen. The reason the extra washer puzzles me is because my example has the expected square spacer but also has this (probably quite expensive to manufacture) countersunk washer in addition. However, there is evidence of the loco having previously been apart (lack of top bearing locknut, butchered front coupling) and so I wouldn't rule out it having gained parts possibly cannibalised from an earlier example. Based on information found on the web, I think mine dates from ~1956-57 so it's not an early one itself.