Victorian/Lambton-style 0-6-0 Coal Engine Scratchbuild

[Corbs]

I've been interested in the NE Coal Railways for a while, in particular the Lambton (later LH&JC) Railway, which inspired a previous 'bash' that was a good test bed for ideas.

 

'Lambtonesque' 0-6-2T bashed from an old Hornby Thomas and a Bachmann Junior chassis.

 

Anyway, I'm in an NCB mood at the moment, one thing led to another and I found this photo of one of the 1866-built Hudswell, Clarke and Rodgers locos on the Lambton Loco Trust's website.

 

 

I really like the low-slung look with the straight running plate unlike the ex-NER locos that some colliery systems had.

 

Looking at what I had in the cupboard, there was another Hornby 'Thomas' chassis and in a drawer some rare 08 wheels (seemingly sold out everywhere at the moment).

After some mucking around with axles, gears and bearings, one fits the other, just.

 

The rods had too much of a sloppy fit so I soldered some washers into them.

 

A GBL C Class tender fitted with top hat bearings and some little wheels is standing in until I can make a proper tender, and here are the rods fitted. Much fettling still to do until they can run properly.

 

Some progress today as I try to make the running plate fit the chassis.

 

 

Fast forward to this evening, testing the frames for fitment before cutting the access holes in. The dome and chimney are resin copies of some nice metal ones. The boiler tube is tacked on to the running plate by the fire and smokebox sides.

 

Currently I am trying to work out how to replicate the distinctive curved roof corners in styrene. Maybe I should make the cab front first which would provide some side-to-side stability.

 

Edited May 19, 2020 by Corbs

[Barclay]

That's some serious model bashing!

 

I would form the styrene over a piece of brass rod or tube, and use heat to keep the shape, either dipping it into near boiling water or even experimenting with heat from a fan heater. It softens quite easily but in the latter case you have to be careful not to go too far.

[Corbs]

Thanks Barclay, in that case I should make sure that the cab front plate has the same radius corners as the rod/tube I'm using?

[phil_sutters]

I would be tempted to use a block of wood as your former. You have quite a complex set of curves there, with an arc over the roof and then sharper curves where the roof meets the cab side. If you plane and/or sand a block, longer than the cab's length, to the shape you need i.e. the shape of the cab front. Once you have wrapped the plastic card around the shape, with the help of a heat source, you can trim the card while it is attached to the block. You can also drill the corners of the side windows and then join them with straight cuts. With the wood behind the cuts and drill holes you should get a cleaner edge. You may have to move the location of the tape or clamps you are using to hold the cab and the block together, as you make the holes and cuts in different areas. I have not tried using this method on a complex set of curves, but it works on simple arcs. I find it easier to cut after forming, rather than battling to get a rectangular roof dead square onto the former while heating it up.

[Ruston]

This looks interesting. Have you got a drawing to work from, or are you guesstimating from the photos? I have a drawing of one of the Hudswell Clarkes if it's any use to you.

[Corbs]

29 minutes ago, phil_sutters said:

I would be tempted to use a block of wood as your former. You have quite a complex set of curves there, with an arc over the roof and then sharper curves where the roof meets the cab side. If you plane and/or sand a block, longer than the cab's length, to the shape you need i.e. the shape of the cab front. Once you have wrapped the plastic card around the shape, with the help of a heat source, you can trim the card while it is attached to the block. You can also drill the corners of the side windows and then join them with straight cuts. With the wood behind the cuts and drill holes you should get a cleaner edge. You may have to move the location of the tape or clamps you are using to hold the cab and the block together, as you make the holes and cuts in different areas. I have not tried using this method on a complex set of curves, but it works on simple arcs. I find it easier to cut after forming, rather than battling to get a rectangular roof dead square onto the former while heating it up.

 

I think you are right, Phil. A former would help get that arc in the roof and the overall width, better than trying to guess it. I think I may have something that would work in getting the big roof arc.

 

16 minutes ago, Ruston said:

This looks interesting. Have you got a drawing to work from, or are you guesstimating from the photos? I have a drawing of one of the Hudswell Clarkes if it's any use to you.

 

That would be really useful, the only references I have are those photos, thank you.

[Corbs]

Today's progress mainly consisted of making up the outside frames. Mine are deeper than the originals, I chose to match the bufferbeam depth as if they were built like that. Marked them up roughly to imitate Lambton 1 & 2.

 

Drilled holes, cut out the areas between them, then used circular files to ream them out.

 

They were secured on with styrene L section tucked under the running plate and have added a lot of longitudinal rigidity to the lower part. I want to add the cab to tie up the back end before trying any more sculpting and shaping on the holes.

 

 

I didn't want to chop up the tender as it's a useful item and GBL aren't around these days, I may need more so decided to try casting the tender body to make resin copies.

 

The box is foamcore stuck together with a hot glue gun.

 

 

Rubber on the left with catalyst being measured for 10:1 ratio.

 

 

This is after the rubber had been poured over a layer of spray-on silicon. I stuck weights to the inside of the tender but something went awry and I returned to the mould to find the tender had floated up! I quickly poured out the viscous rubber, scraped as much as I could out of the tender, rammed it back into the box, then poured the rubber back in. Fingers crossed the damage isn't too bad and the mould is salvageable!

 

Maybe double sided tape would have worked better to stick it down to the foamboard.

 

 

[chris p bacon]

40 minutes ago, Corbs said:

Maybe double sided tape would have worked better to stick it down to the foamboard.

 

When casting you must always stick the item down as any air will fight the silicon and bring it to the top (we've all done it).

 

[Michael Edge]

I stick patterns for moulding down on the bench top with double sided tape and build a Lego box round them but yes, they do have to be fastened down.

[Corbs]

Hmm I had hoped that the weights would have been sufficient, in the past I have used black tack to form a seal around the item but didn’t have enough to go around in this case. Lesson learned!

[burgundy]

 I don't think it is just trapped air. I think the curing process may create gas which fills any convenient space. I once tried doing a mould to produce sheeted open wagons as a single piece resin casting. It worked, but, instead of a sagging wagon sheet, I got one like a balloon.  

See the right hand vehicle below. 

It is amazing what a bit of paint will do - left hand wagon.

Best wishes 

Eric 

[Corbs]

Cheers Eric

Long story short, the casting was a disaster and has been thrown in the bin. The silicon spray wasn't enough to keep the two halves separated, the cling film I'd put on did work but didn't extend to the edge so the second half ended up going around the cling film and bonding to the first half.

I attempted to cut it out in what I thought was the right place, ended up being halfway down the tender.

 

Stupidly I should have realised this, when I have done 2-part moulds before I built up the item with styrene to give it a lip, so the join was not on the item to be cast but on the 'wastage' section.

 

I've ordered some plasticine and will try again.

On the brighter side, I've been using blue and green stuff to cast some springs which did come out well. Small victories do help, especially when you need as many springs as this loco requires!

[Corbs]

Yesterday I made some progress on the cab. The front spectacle plate was made first, shaped to fit to the boiler so when glued together it adds some structural rigidity.

After much folding and measuring, the roof and sides were cut out. As an experiment I first wanted to try forming it around the tube in the background, as that was what I'd used to draw the curves on the front plate.

 

This is it after some heating, forming, bending.

 

I'd glued in a cross brace to locate it in the right place on the chassis block, and 4 L section strips to help clamp the front plate in place.

 

 

Here it is roughly plonked together. The cab is longer than the Lambton equivalent because my chassis sticks out further at the back, so I've reduced the length of the forward sticky out bit of the side of the cab to help bring the overall size down. Adding the side windows should also help break up the slab-sided look it has now.

The smokebox front was made by drawing round the front of the boiler, cutting out of styrene and glueing on, then filing to shape.

 

 

 

 

[bgman]

Just came across this intestine build and looking very promising.

 

Just out of interest regarding your moulding process, have you considered using this product for smaller parts

 

 

Whilst I have successfully used rubber moulds over the years I have found the Siligum to be just as useful for smaller items and it also has a rapid curing time to enable work to progress. It isn't that expensive or wasteful which is a bonus !

 

Grahame

[Corbs]

Thanks Grahame, will give it a go, looks like it might be the ideal middle ground between the full silicon rubber moulds and the green stuff/blue stuff.

 

Did some more on the 0-6-0 recently, added a cab floor which helped brace it, and cut the side windows. As the cab is longer than Lambton 1 & 2, I spaced the windows out more so they wouldn't be either overly wide or hunched together in the middle of the side sheet.

 

The Lambton locos tended to have some rather nice spectacle shields, so to try and emulate that I sliced up a piece of plastic tube (which was a paintbrush cover).

 

One of my favourite parts of any build is the first blast of primer, because it ties everything together, so once I'd glued the cab on and fashioned up the turn-ins for the side sheets, it went rather grey.

 

 

Will likely add a rain strip to the roof to break up the curve as the top of the window frame bends in slightly, unlike the prototype. Lots of filing and filler work to follow.

 

[Corbs]

Deep breath...

 

2nd attempt at doing the tender as my plasticine arrived today. Multicoloured is cheaper than a single colour, presumably because it goes through an incredibly vibrant phase before becoming brown forever.

 

I rolled and kneaded it a lot, then rammed it into one side of the chassis and the body, filling the void inside the body too. Excess was trimmed to make it neater/ish.

 

 

This used an unprecedented amount of glue sticks to make the mould box, and silicon rubber too. 600ml of the stuff, I actually calculated the volume of the box and subtracted the amount displaced by the body and chassis for once.

For belt and braces, I also glued the plasticine to the base, and attached some bits of random plastic to act as registration guides for the two mould halves.

 

 

Because I strongly suspect my workbench and layout are not level, I've left it on the kitchen worktop overnight to try and give it the best chance of curing level.

 

 

[Barclay]

I wouldn't say working from home is getting to me, but I am quite excited to see how it looks this morning !!

[Nile]

Yum! What's for breakfast?

[Corbs]

Ahhh it may have to be a bit longer I'm afraid - it'll be tonight at least, because it's only been around 12 hours so far. I've tested the rubber in the mixing pot which is still semi-liquid so will be leaving it well alone.

What I was wondering was whether I should try a different rubber for the B side of the mould to try and avoid the constant issue I have of the mould halves sticking together?

[Corbs]

1 minute ago, Nile said:

Yum! What's for breakfast?

It does remind me of the pink custard we used to get in primary school lunches....

[burgundy]

3 hours ago, Corbs said:

What I was wondering was whether I should try a different rubber for the B side of the mould to try and avoid the constant issue I have of the mould halves sticking together?

What release agent are you using?

Best wishes 

Eric 

[Corbs]

3 minutes ago, burgundy said:

What release agent are you using?

Best wishes 

Eric 

Hi Eric,

 

At first I was using Ever Build All Purpose Silicon Spray, but I've just in the last few days got some Mann Ease Release 200 spray. The first one (when used with castings) tended to leave a mottled effect whereas the newer stuff is better.

 

Is there one you would recommend to stop the rubber sticking to itself?

 

Many thanks

[burgundy]

I used to get my supplies from Tiranti and their current recommendation seems to be this one. It looks different to the can that I remember, but that is hardly surprising, given that it is a good few years since I did any casting. I also seem to recall using diluted Vaseline as a coating - probably painted onto the patterns so that they would come out of the mould.

Hope this helps

Best wishes

Eric   

[Corbs]

Thanks Eric, I did a bit of digging and it sounds like the silicon spray I was using may have actually been encouraging the mould halves to stick together!

This website mentions the ease-release which I have so fingers crossed it'll be the tool for the job

 https://www.smooth-on.com/support/faq/94/

[bgman]

If you are really stuck then a thin coat of vaseline applied with a brush works.