Painting loco boiler

[manofkent]

Hi all.

I am about to start painting the boiler of my 3.1/2 gauge Bantam Cock.

The boiler has a brass cladding with insulation.

I know I need to use some etch primer first.

I then want to use undercoat, before a final paint colour.

Can anyone suggest a suitable etch primer and a suitable undercoat , given the higher temperatures that will be present on the painted surface?

Many thanks 
John

[92220]

Hi John.

Phoenix Precision Paints 2-pack etch primer, and al;l their railway colours, are fine for use on loco boilers.
For undercoat, you can use the "Dull" version of the gloss topcoat. I don't know if you will use L.N.E.R. Doncaster Green or Darlington Green, but both are available in both Dull and Gloss. There are other model paints on the market you could use, but I know Phoenix Precision is formulated suitable for use on live steam models.

Don't forget to degrease with cellulose thinners before applying the etch primer. Don't do as some do, 'clean' with washing up liquid. It DOESN'T clean up suitable for any surface to be painted. Washing up liquid ALWAYS leaves a film on the surface that paints don't like adhering to. You've seen the advert for Fairy washing up liquid. It states that the dishes are left with a bright shiny surface. That shiny surface to a non-toxic coating that all washing up liquids leave, that is very difficult to remove, once there. Cellulose thinners and a clean, cotton, cloth, is the best way to degrease.

Bob.

[cplmickey]

I know this is one of those "How long is a piece of string" type questions but I would be interested to hear how much paint has been used on locos of different gauges. I am about to start painting my 7 1/4 gauge L&B Lyn (so a large narrow gauge engine in 7 1/4) and have no idea how much paint to buy. I can get 50ml, 125ml and 250ml tins in the colour I want and am thinking I will need 250ml but will this be enough? I don't want to buy too much given the price but at the same time I'd like to buy enough for the engine to avoid possible shade matching problems if I need more. Any pointers please. Thanks, Ian

[GWR 101]

John, apologies for using your thread. Regarding painting a 71/4" L&B, I helped in making parts for our club L&B project although not directly involved in the painting. I have asked one of our members who undertook the painting and he believes that the following was an estimate. 1 litre of primer, 2 litres of green and 2 of black undercoat, half the amount of each in top coat. The undercoat depends how much you wet and dry it, I understand that the tanks alone took several weeks. If you look on the SCMES web site you will see that it was modified to a loco and tender so you may need slightly less. I hope this is of some help. Regards Paul

[mbrown]

I found I needed much more paint on the Burma Mines loco, where I had loads of problems with specks of dust, runs etc, than on other locos where the painting went much more smoothly. Fortunately (perhaps) the colour I wanted was only available in one litre cans so I had loads, and needed far more than I expected.

I think much depends on your skills, painting conditions, and other extraneous factors rather than the size of the model.

Malcolm

[simplyloco]

Dec 2, 2021 17:54:52 GMT mbrown said:

I found I needed much more paint on the Burma Mines loco, where I had loads of problems with specks of dust, runs etc, than on other locos where the painting went much more smoothly. Fortunately (perhaps) the colour I wanted was only available in one litre cans so I had loads, and needed far more than I expected.

I think much depends on your skills, painting conditions, and other extraneous factors rather than the size of the model.

Malcolm

Any painting problems I might have had largely disappeared when I started using automotive two pack paint. The Stirling Single was painted entirely with the stuff and look how that turned out!

[mbrown]

I have already decided to go for two-pack when the current project is ready for paint - which is easier since everthing is either black or bright red and no complex livery-matching is needed!I even have the RAL numbers from the Deutsche Reichsbahn!

I must look back through your Stirling Single thread and see how you applied it. I have always used a very simple external-mix airbrush to date.

Malcolm

[simplyloco]

Dec 2, 2021 20:45:04 GMT mbrown said:

I have already decided to go for two-pack when the current project is ready for paint - which is easier since everthing is either black or bright red and no complex livery-matching is needed!I even have the RAL numbers from the Deutsche Reichsbahn!

I must look back through your Stirling Single thread and see how you applied it. I have always used a very simple external-mix airbrush to date.

Malcolm

I tried with both of my airbrushes but they don't deliver enough volume of thick enough paint, and no fan effect is available. I used my Kite minigun with a 0.4mm nozzle.

[manofkent]

Hi all.
Great comments. I was also wondering about how much paint to use, so that is very helpful.
Thanks for the comments to all.
Bob (92290). I remember I do actually have some GWR green paint from Precision Paints left over from a different project (non steaming loco), so I will give it a go with that first.
I am using Precision Paints etch primer, and their paint thinners to degrease and clean the surfaces.
I know Bantam Cock is an LNER loco, but I want to paint it in post 1956 BR green - a darker colour but I hope will suit it well. I am starting on the cab, so that will give me a better idea how it will look.

Thanks

John

[cplmickey]

Dec 2, 2021 17:36:57 GMT GWR 101 said:

John, apologies for using your thread. Regarding painting a 71/4" L&B, I helped in making parts for our club L&B project although not directly involved in the painting. I have asked one of our members who undertook the painting and he believes that the following was an estimate. 1 litre of primer, 2 litres of green and 2 of black undercoat, half the amount of each in top coat. The undercoat depends how much you wet and dry it, I understand that the tanks alone took several weeks. If you look on the SCMES web site you will see that it was modified to a loco and tender so you may need slightly less. I hope this is of some help. Regards Paul

Wow, that's so much more than I imagined. Thanks so much for that information - probably stopped me making a booboo! Ian

[chris vine]

I found that I needed about 10 times the amount of paint that I was originally advised to get.

It is much better to buy a litre or two, then you won't be too stingy when mixing the paint for the spray gun, and then run out in the middle of a job. Yes, that happened to me.
Also, I had to repaint large items like the boiler and tender tank several times to get it right.

If you buy enough paint in one, large, tin, then at least you know it will all be the same colour!!

Chris.

[Roger]

Dec 2, 2021 22:18:45 GMT cplmickey said:

Dec 2, 2021 17:36:57 GMT GWR 101 said:

John, apologies for using your thread. Regarding painting a 71/4" L&B, I helped in making parts for our club L&B project although not directly involved in the painting. I have asked one of our members who undertook the painting and he believes that the following was an estimate. 1 litre of primer, 2 litres of green and 2 of black undercoat, half the amount of each in top coat. The undercoat depends how much you wet and dry it, I understand that the tanks alone took several weeks. If you look on the SCMES web site you will see that it was modified to a loco and tender so you may need slightly less. I hope this is of some help. Regards Paul

Wow, that's so much more than I imagined. Thanks so much for that information - probably stopped me making a booboo! Ian

I'd be interested to know if most people use two coats. I've just used one coat of etch primer and one top coat. That way you preserve the detail. I know of at least one prolific builder who only ever uses one coat, and his locomotives look great.

[ettingtonliam]

According to the late John Reeves (founder of A J Reeves) LBSC only ever used one coat of paint. Mind you, his technique, apparently, was to build and test the loco, then wash it down with paraffin, and apply one brush coat to the accessible parts---.

[Cro]

Dec 3, 2021 8:23:09 GMT Roger said:

Dec 2, 2021 22:18:45 GMT cplmickey said:

Wow, that's so much more than I imagined. Thanks so much for that information - probably stopped me making a booboo! Ian

I'd be interested to know if most people use two coats. I've just used one coat of etch primer and one top coat. That way you preserve the detail. I know of at least one prolific builder who only ever uses one coat, and his locomotives look great.

Yes but he puts it on fairly thick to get that coat (not to the detriment of the detail). When I did the 5 each component had 2 undercoats and 1 top coat. 

Adam 

[simplyloco]

Dec 3, 2021 8:23:09 GMT Roger said:

Dec 2, 2021 22:18:45 GMT cplmickey said:

Wow, that's so much more than I imagined. Thanks so much for that information - probably stopped me making a booboo! Ian

I'd be interested to know if most people use two coats. I've just used one coat of etch primer and one top coat. That way you preserve the detail. I know of at least one prolific builder who only ever uses one coat, and his locomotives look great.

The Stirling had one coat of etch primer and one top coat. Any surface with acrylic lining on it required a further coat of clear lacquer to seal the paint. That's why it was so shiny!

[cplmickey]

Dec 3, 2021 8:45:08 GMT Cro said:

When I did the 5 each component had 2 undercoats and 1 top coat. 

Adam 

That's interesting because I do the opposite - 1 undercoat and 2 top coats (on the black items). When I painted the Simplex cab and boiler I think I did 2 of each.

[92220]

Dec 3, 2021 8:23:09 GMT Roger said:

Dec 2, 2021 22:18:45 GMT cplmickey said:

Wow, that's so much more than I imagined. Thanks so much for that information - probably stopped me making a booboo! Ian

I'd be interested to know if most people use two coats. I've just used one coat of etch primer and one top coat. That way you preserve the detail. I know of at least one prolific builder who only ever uses one coat, and his locomotives look great.

Hi Roger.

Correct. Only one coat of etch primer should ever be used. As long as there is a complete coating, it will do it's job. It is only there to act as an adhesion coating for the undercoat or topcoat. Putting a second coat of etch primer on, can, in some circumstances, adversely effect the first coat of etch primer. On a model, if an undercoat is wanted, then a coat of them dull version of the gloss top coat is all that is needed. As you rightly say, too many coats start to hide detail. As long as the one top coat is just thick enough to cover completely, that is all that is necessary, because the paint is only there for visual effect, not for protection as in most non-modelling cases. Also: the more coats applied, the more chances or foreign bodies, like flying insects, dust and hairs. 

Hi cplmickey.

I would think 1 litre would be more than enough for your L & B Lyn. 1/2 litre would probably do, but would be close. As far as other locos go, I would normally suggest a 250mls tin should cover a large 5" gauge tender loco with one coat. 2 coats - 2 x 250mls for safety. A large 3.1/2" tender loco, a single 250mls tin is more than enough. A small tender loco could be done with 125mls, and a small loco could be done with a 50mls tin. Those are all assuming just one coat. A lot depends on how the paint is applied. Spraying can put over 50% of the paint on the surrounding area, and not on the model, so would be wasted, and so a lot more would be needed. 

Bob.

Bob

[cplmickey]

Dec 3, 2021 9:49:36 GMT 92220 said:

I would think 1 litre would be more than enough for your L & B Lyn. 1/2 litre would probably do, but would be close. As far as other locos go, I would normally suggest a 250mls tin should cover a large 5" gauge tender loco with one coat. 2 coats - 2 x 250mls for safety. A large 3.1/2" tender loco, a single 250mls tin is more than enough. A small tender loco could be done with 125mls, and a small loco could be done with a 50mls tin. Those are all assuming just one coat. A lot depends on how the paint is applied. Spraying can put over 50% of the paint on the surrounding area, and not on the model, so would be wasted, and so a lot more would be needed. 
Bob

Thanks Bob, that's useful guidance.

I'm undecided about spraying or brush painting. I get quite a lot of practise with the brush on the narrow gauge locos we restore and am aware that spraying can result in very thin coverage requiring far more coats. The main issue for me is that brush marks don't scale - what's ok on a 2ft loco looks terrible on a 7 1/4 one. Ian

[92220]

Hi Ian.

With spraying, to make sure you have a solid coating, you can spray all over, and then go back to the start and do another spray coat, before the first has dried. That way, you can build up a thicker coat with no intercoat adhesion problems. They all become one homogeneous coat. With a loco of that size, I would think a 25% thinning of the paint, for spraying, would give pretty good coverage too. A lot does depend on what equipment you have too. An airbrush would take ages to paint the whole loco. A Kite Mini Spray Gun, is ideal for the larger locos, but it does need a compressor. The airline also needs a water trap. Some cheaper compressors come with the filter/watertrap connected to the compressor. Useless!! The air needs to be cooled so that any water vapour condenses out, so there should be at least 6 feet between the compressor/tank outlet and the watertrap. The watertrap needs to be the mini size (about 1" diam bowl), otherwise the air, when spraying, doesn't move fast enough to spin out the water droplets, in the watertrap.

Bob.

[Roger]

Dec 3, 2021 10:42:16 GMT cplmickey said:

Dec 3, 2021 9:49:36 GMT 92220 said:

I would think 1 litre would be more than enough for your L & B Lyn. 1/2 litre would probably do, but would be close. As far as other locos go, I would normally suggest a 250mls tin should cover a large 5" gauge tender loco with one coat. 2 coats - 2 x 250mls for safety. A large 3.1/2" tender loco, a single 250mls tin is more than enough. A small tender loco could be done with 125mls, and a small loco could be done with a 50mls tin. Those are all assuming just one coat. A lot depends on how the paint is applied. Spraying can put over 50% of the paint on the surrounding area, and not on the model, so would be wasted, and so a lot more would be needed. 
Bob

Thanks Bob, that's useful guidance.

I'm undecided about spraying or brush painting. I get quite a lot of practise with the brush on the narrow gauge locos we restore and am aware that spraying can result in very thin coverage requiring far more coats. The main issue for me is that brush marks don't scale - what's ok on a 2ft loco looks terrible on a 7 1/4 one. Ian

Spraying certainly has its challenges, but getting enough paint on isn't one of them in my opinion. Dust is the number one enemy, and it's worth constructing a filter arrangement with plenty of air flow so that you can leave a room recirculating air through it to remove as much as possible. Remember what the light from a projector looks like, with the dust brought sharply into focus and you'll see how difficult this issue is to solve. I leave the room sealed and filtering for several hours before painting.

The second issue is being able to move the part around while you're spraying it so that you can get to every angle and face in one pass. 3D printed mounts are one solution to this, and a revolving 'spit' is really helpful. If that's motorised it's even better, because you can paint any shape in any orientation and the paint doesn't have a preferred direction to sag or run towards. It all takes a lot of thought and preparation, but it's worth every minute in my opinion.

The best tip I can pass on that I've not seen anywhere else is to use masking tape as a sticky dust collector. I stick it down to every surface I'm painting and pull it off. You may think the surface is clean, but you'll almost certainly leave something behind if you don't take extraordinary precautions.

There's a lot in my thread about this, if that's the route you want to take.

There are many other ways to go about this of course, I can only tell you what I did and why I did it.