The Heybridge Railway, 1889 to 1913

[Ian@StEnochs]

Painting metalic effect is not simple and there is an easier way. Brass leaf. The dome on this model is the whitemetal casting supplied with the kit covered in brass leaf. To apply it was a case of painting the dome with varnish and laying the foil over it with a stiff brush. Once dry I gave it an overall coat of varnish as the brass leaf does tarnish. It is actual metal after all.



I cannot find the make that I used online but there are lots of suppliers on ebay and the like or here Imitation Gold Leaf - Transfer

Ian.

 

[RichardG]

I suppose a gold leaf of (say) 9 carats will have a colour very close to that of brass. Definitely something to think about, thank you Rob and Ian.

 

[simond]

Thank you, Rob, Ian and Richard.

I can now imagine an experimental route to making convincing GWR number and name plates from 3D prints.

 

[RichardG]

I am just wondering who will be first to wrap a 3DP body shell in gold leaf to give it that no-solder pro builder look

 

[Rob Pulham]

I am the friend that Richard referred to when mentioning the safety valve cover brass painting. I had idly mentioned to Richard to polish the metallic paint after it dries with either a cotton bud or kitchen paper. It was during this discussion that it occured to me to use a buffing wheel in a mini drill instead.

I dug out a whitemetal safety valve casting from my H2/J79 kit and after buffing up the casting I brush painted some Vallejo Old Gold onto it. and then when dried overnight buffed it with the mini drill. Getting decent photos of it proved quite a pain but I got something.



Then it occured to me to to add a coat of Johnsons Klear (I noted that Tony @Osgood had suggested similar the follwoing morning)



I still wasn't too happy with the result but at this point I thought that it was down to the finish of the casting so instead of using a buffing wheel I used a wire cup brush in the mini drill. At the same time I thought it prudent to also polish up a brass casting so I could have a proper comparison the casting in question is a Gladiator example as I had bought a number of them from David to replace the whitemetal casting in a number of ex NER loco kits.



It was at this point that I realised that my Old Gold was not the right colour but I was part way through the next experiment so I ran with it.

My third example is another whitemetal casting this one from my J71 kit and the sequence was was polish the casting with a wire brush then spray rather than brush more Old Gold but this time let down for spraying with Johnsons Klear.

Here are the three together. The polished and sprayed example is by far the best in terms of finish but the colour is wrong when in direct comparison to the actual brass.



I consulted my good lady as to what I might need to add to the old gold to make it more like the brass example and she suggests white or silver to make it paler. I don't have anymore safety valve castings to hand so I was going to use a dome instead but in the interests of keeping them all similar I elected to stripp the paint off the first expample so that I could polish the casting with the wire brush before trying again with a lighter hopefully more brassey colour. TBC

As an aside I thought perhaps I could cut out the stripping stage by attacking the painted casting with my wire brush in the mini drill. I was really surprised that it didn't budge it. Despite giving it a good going over all it did was further polish the surface so those who doubt the toughness of modern acrylics take note. Now the casting is soaking in some clean spirit to soften the paint before i have another go.

 

[Rob Pulham]

I should also add that I really like Ian's brass leaf finish, it looks superb to me.

 

[RichardG]

I should also add that I really like Ian's brass leaf finish, it looks superb to me.

Yes it is definitely something I want to aspire to on a future model. Or even, on a replacement safety valve cover on the H2.

 

[Ian@StEnochs]

I am the friend that Richard referred to when mentioning the safety valve cover brass painting. I had idly mentioned to Richard to polish the metallic paint after it dries with either a cotton bud or kitchen paper. It was during this discussion that it occured to me to use a buffing wheel in a mini drill instead.

I dug out a whitemetal safety valve casting from my H2/J79 kit and after buffing up the casting I brush painted some Vallejo Old Gold onto it. and then when dried overnight buffed it with the mini drill. Getting decent photos of it proved quite a pain but I got something.

View attachment 259624

Then it occured to me to to add a coat of Johnsons Klear (I noted that Tony @Osgood had suggested similar the follwoing morning)

View attachment 259625

I still wasn't too happy with the result but at this point I thought that it was down to the finish of the casting so instead of using a buffing wheel I used a wire cup brush in the mini drill. At the same time I thought it prudent to also polish up a brass casting so I could have a proper comparison the casting in question is a Gladiator example as I had bought a number of them from David to replace the whitemetal casting in a number of ex NER loco kits.

View attachment 259626

It was at this point that I realised that my Old Gold was not the right colour but I was part way through the next experiment so I ran with it.

My third example is another whitemetal casting this one from my J71 kit and the sequence was was polish the casting with a wire brush then spray rather than brush more Old Gold but this time let down for spraying with Johnsons Klear.

Here are the three together. The polished and sprayed example is by far the best in terms of finish but the colour is wrong when in direct comparison to the actual brass.

View attachment 259627

I consulted my good lady as to what I might need to add to the old gold to make it more like the brass example and she suggests white or silver to make it paler. I don't have anymore safety valve castings to hand so I was going to use a dome instead but in the interests of keeping them all similar I elected to stripp the paint off the first expample so that I could polish the casting with the wire brush before trying again with a lighter hopefully more brassey colour. TBC

As an aside I thought perhaps I could cut out the stripping stage by attacking the painted casting with my wire brush in the mini drill. I was really surprised that it didn't budge it. Despite giving it a good going over all it did was further polish the surface so those who doubt the toughness of modern acrylics take note. Now the casting is soaking in some clean spirit to soften the paint before i have another go.

Brass castings that we modellers use come in different alloys. Not all reproduce the ‘Brass’ colour of prototype brass fittings well. The example you have Rob looks a bit on the silver end of the spectrum where in reality these safety valve trumpets were made from sheet brass which has a colour more at the gold end.

This is not a criticism but an observation. I just had a look through my box of castings and they cover a range from almost steel to nice deep yellow. I took a picture but it just doesn’t show the differences as clearly as I expected. The buffers probably show the differences best but as they will be painted the colour doesn’t matter.


I added in a tank filler to the photo which I recently turned from brass bar and this looks nearer to the brass finish of the real thing.

Ian.

 

[Rob Pulham]

Brass castings that we modellers use come in different alloys. Not all reproduce the ‘Brass’ colour of prototype brass fittings well. The example you have Rob looks a bit on the silver end of the spectrum where in reality these safety valve trumpets were made from sheet brass which has a colour more at the gold end.

Ian.

I wholeheartedly agree Ian.

Indeed I made the comment to Richard in a PM that in isolation all our efforts will probably pass muster, it's only when we put them alongside actual brass that we start to doubt things.

Taking aside the different alloys that make up brass for different jobs, new polished brass also looks different from aged, polished brass, that has been polished numerous times over the years. In many respects we are on a hiding to nothing whichever route we take. But that's the fun of trying to model the real thing in miniature.

 

[alastairq]

In my yoof, as a navigating apprentice in our esteemed merchant navy, I recall polishing brass [binnacles] using HP sauce, of all things!

Much to my surprise it worked......but left an interesting smell for a few days afterwards. Much nicer smell than Brasso!

 

[RichardG]

Yes. I find tomato ketchup to be a convenient way to get acetic acid (in vinegar) in paste form. Just don't let it dry on, it becomes a nuisance to remove.

I expect HP sauce removes tarnish in much the same way as tomato ketchup, which I posted about a while ago. I guess both are easy to find on board a ship

 

[RichardG]

I have made a start on wiring up the NER H2 . . .


The loco is receiving seven NiMH batteries, these ones are two-thirds AAA size and branded ‘Digimax’.

Choosing NiMH technology removes the worries associated with LiPo, and I can use the charger from my similarly-powered Y14. I have a feeling, 400mAh is plenty of capacity to drive the incredibly efficient motor in the Slater’s SG38.


Test running has shown, with the seven batteries partly charged as supplied (8.4 volts off-load), the loco can reach a scale 23 mph. This seems just right to me, which is fortunate because shoe-horning in an eighth battery would be difficult if not impossible. Charging the batteries takes this up to just over 9 volts.


The batteries are in three groups, one for the boiler and one for each side tank. The ones in the side tanks are short enough to leave room for a power switch on one side and a fuse on the other.


I have gone for one fuse for the whole battery pack. I expect some experts will tell me how potentially dangerous this is but to be honest, I think an open circuit is far more likely as a failure mode.

Thinking about only single fault conditions:

• the charging socket connects the negative side of the battery pack to the metalwork of the model, and so a short circuit across the entire battery pack is possible in the wiring outside the battery pack or in the r/c board.
• a short circuit within one group of two or three batteries needs the factory insulation around an individual battery to fail. This is unlikely, because the heatshrink prevents movement and chafing.

So this is a 3 amp fuse, large enough to never blow in normal operation and placed here as a last resort to save the model before a fire gets underway.


Here are most of the electrical parts to be fitted into the model.


The charging socket is the first part to be fixed into place. This is an interference fit into the chimney, and it is now there forever unless I choose to destroy it by taking it out. I don’t like this sort of approach to assembly but there is very little free space to play with. Putting the socket here is easier than putting it in the coal bunker because the wiring ends up where it is wanted.


The power switch had to be wired up before fixing it into the model, this is fast-setting epoxy glue. Thanks to @simond for the suggestion to put the switch here, the result is going to look really neat yet still accessible and easy to use.


Here are the power switch, the fuse (opposite the switch) and all of the batteries. What seemed like a huge empty space is getting filled up. I have enough room for the Micron MR603 receiver or the motor, but not both. So the assembly pauses again while I await a smaller receiver, this will be the Micron MR601.


In the meantime I have a temporary lash-up so I can give the loco some test runs.

I have touched in the paint along the edges of the running boards! These are now enamel, the Vallejo acrylic was just falling off through handling the model.

 

[simond]

Richard.

Glad to have helped. Before you close it up, treat yourself to a polyfuse, to replace that glass thing!

RUEF300 | Littelfuse 3 A Resettable Fuse, 30 V dc | RS

uk.rs-online.com

47p each, self resetting fuse

Best
Simon

 

[RichardG]

Before you close it up, treat yourself to a polyfuse, to replace that glass thing!

I can imagine a self-resetting fuse can turn a permanent fault into an intermittent one. I'd want to put an LED and a resistor across the fuse so I could see when it had operated.

 

[simond]

Fair point and good solution.

I’ve been lazy and not done that on my Hymek. But the time to reset is long (minutes?) and presumably the fuse only but always opens in certain situations, and it’s 3A which is probably >> the load it’ll ever see…

 

[RichardG]

I’ve been lazy and not done that on my Hymek.

When I was working with medical devices, I spent a lot of time assessing the possible hazards arising from normal operation and a single fault condition. Normal operation is fairly self-explanatory but it does include foreseeable misuse.

For an electrically-powered model railway loco, the most obvious foreseeable misuse is running it into an obstruction such as buffers or a heavy train. The loco will then either stall (a high current condition) or pick up its heels. My locos are light enough to spin their wheels.

For a loco powered by rechargeable batteries, I suspect the most likely fault condition is excessive charging current - because this involves an item of additional equipment, the charger. When the battery pack in the model is a series arrangement of single cells, such a fault looks like a charger problem rather than a battery problem. My own charger is a “smart” one in that it adjusts its charge current to suit the load it detects. This looks like something able to go wrong, and I ought to put a smaller fuse in the output lead from the charger.

A piece of conductive foreign object debris (avionics term) might bridge two conductors close together. The only place this can happen is on the controller board, and this is mitigated by the sleeving around the board.

Finally, I could have a fault with my construction inside the model. A wire falling off is the most likely and this can cause a hazard if it happens to be at the battery +ve voltage and touches a bare part of the metalwork. Yes there is paint on the chassis and inside the body, but the motor and axles are bare metal. This is the only real reason for putting in a fuse. I wish I had arranged the charging socket to be insulated from the metalwork but this is something for the next model.

The most insidious fault would be a short circuit inside one of the three groups of batteries, in which a positive terminal chafes its way though the factory wrapper on an individual battery. This could cause a big problem. My own feeling is, the terminals are not under stress, and my outer wrap of heatshrink secures them to stop them moving. So the probability drops so low (and this is a model train not a medical device) no further protection is necessary.

If the Hymek is a Big Big Train one, the opportunities for faults with a plastic-bodied model must surely to be smaller.

The MR603 is due to arrive today

 

[simond]

I'm familiar with "single fault condition discussions"

A short-circuit fault within the battery pack would be bad news indeed, the fuse will offer no protection. Reputably-supplied 18650s should have an overpressure relief valve which will cut the current. That should save an internal battery fire. I use 18650s in the Hymek, and will remove them for charging. Not been need yet. Your NiMH are way safer than Lithium cells, but they can still provide meltingly-high currents,

The Hymek is indeed plastic bodied ex Big Big (I bet whoever said "commercial 0 gauge will never happen in the UK, sell the tooling off cheap to the Russkies" is probably kicking themselves) so the chances of a short are much reduced. The battery plugs into a harness that plugs into the RC receiver and to the two motor bogies, and the lamp harnesses also plug in. Broken wire aside I think we'e in a reasonably safe place!

best
Simon

 

[Yorkshire Dave]

Could induction charging be utilised?

InduktivCharger | Faszination der Modellwelt erleben
Empfängerspule zum Nachrüsten für CarMotion LKW und Busse

 

[RichardG]

Could induction charging be utilised?

Inductive charging wants the two coils to be quite close to each other. So for a tank loco, perhaps one tank side could be made of plastic, with the secondary coil fixed onto the inside of it. The primary coil placed onto something resembling a very close bridge abutment in the fiddle yard.

I have a mental list of slightly way-out loco charger connectors including buffers even wheels. I'll happily add this to the list

Those Viessmann model cars and buses could tempt me back to H0, a different hobby really.

 

[magmouse]

I have a mental list of slightly way-out loco charger connectors including buffers even wheels.

Seems to me a couple of contacts underneath the loco would be a better option, with corresponding contacts between the rails in the fiddle yard, or disguised in some way.

It could be very proptypical, if one were modelling this...

GWR rapid-charging battery train trial successful

A rapid charging system could replace diesel vehicles at Great Western Railway.

www.bbc.co.uk

Nick.