Paint

Ken,

Timely question. I was just going through the 1951 Model Railroader magazine's and re-reading Mel's article on scratch building an O gauge 0-4-0 switcher. And I think I have come across talk of Mel mixing his own. Unfortunately I don't have the last issue of this series which might have given a clue as to painting. I'll have to check some of the other articles by Mel and see if I can find something on paint preparations.

Ok, now to your question. I think it would be "very" rare to find a model railroad hobbyist that goes to that point to mix their own paint. The linseed oil I think gave a smooth consistency to the pigment and lacquer thinner is the medium. An oil based paint would take to long to dry.

Bernd

Bernd, here's the paint scheme from Mel's Article

from Sept 1951 MR. Last paragraph in article talks about paint. Quote

"Paint the loco and tender black; the smoke box a medium slate grey to copy the graphite coating; the cab roof,
back of tender coal board  and manhole, indian red; and the cab interior, medium chrome green.
Letter with medium chrome yellow.
To be fancy, dress the tire rims, footboard and running board edges with white."

He doesn't mention paint preparation at all.

Hope this helps

Randy

Mels article

Thanks Randy. I do remember something mentioned somewhere that he did mix his own paint.

I have a request. If that's the last article in the series, could you scan that and e-mail it to me? I'd really appreciate it. Thanks.

Bernd

I could just tryi it, I guess

If I remember correctly, the article was specifically about paint, and not about any particular locomotive.  I think the locomotive used for illustration was his B&O 4-6-0, but I could be wrong there.  I recall the article also discussing hand lettering, and he clamed that the home-made paint covered extremely well and flowed beautifully so that the lettering came out crisp and smooth.

Mel's work was always impressive!

What I'm wondering is whether it might be worth the hassle.

• Would a paint made using oil paint that I can get anywhere (I have some for weathering that I bought at Wal-Mart), linseed oil, and lacquer thinner even work, or are the oil paints incompatible with the other two ingredients?
• What properties would such a paint have?  Would it cover well?  Would it go through an airbrush well?  How thin and even a coat could you lay down?
• What effect would varying the proportions have on the paint?  Specifically, (since I assume that the thinner just makes it, well, thinner) how critical is the ratio of pigment (or artist's oil paint, in this case) to binder (linseed oil).
• Would a more modern product, such as polyurethane varnish, work in place of the linseed oil?  I suppose I could just try it, since I have plenty of varnish, paint thinner, and oil paint on hand, but I'd be curious to hear form someone who might actually know what they're talking about.
• What about a water-based variation, using acrylic paint and water based polyurethane?

The idea of being able to mix up any color I need without having to stock a blue million bottles of paint, and without having to pay for all that paint, is definitely appealing to me.  It seems like a fairly limited stock of paint tubes and an inexpensive can of linseed oil and thinner could replace an entire hobby shop shelf, if it's practical.  So I guess that's the ultimate question.  Is this a useful skill which has been forgotten due to convenience and laziness, or is it really not practical to replace a commercial product with a homemade one?

Useful Skill

One of the tells

Ken the article in MR july

Ken the article in MR july ,aug, sept 1951 is about construction of the loco and tender. There must be another one that deals with the paint process.

If you have the MR disks, you can try to find it. The search on the disk set is the worst I've seen. It's terrible. Wa to go MR!!

Randy

It's not just the color

While being able to make custom colors would certainly be useful, I'm wondering more about the mechanical side of the problem at the moment.  How would the resulting paint compare to something like Floquil?  I think that's where artists and modelers differ.  An artist is (I assume) more worried about the color than about the physical properties of the paint, especially in how think it can go on and still give an even color capable of covering others beneath it. 

Are dry pigments readily available for a reasonable price?  Are they ground as fine as we need for our models?

I have a feeling that it's a skill which would have to be developed.  I bake bread, and I've been doing it long enough that I rarely measure any of the ingredients.  I just know when it's right because it looks and feels right.  I suspect that making paint would be somewhat similar.  Start with the pigment, then add the binder until it's right, and then add thinner until it's the right consistency.  In large batches, you could measure the weight or volume, but for a small batch (like a single airbrush load) I think you'd just have to eyeball the ratios and adjust until it works.

Bernd, I sent off a pm to

Bernd, I sent off a pm to you.

There's six pages I scanned into  ms word.

Let me know where to send em.

Randy

" a useful skill which has been forgotten due to convenience "

   The paint choices in the old days was very poor compared to what we have now so a lot of the techniques you read about were from necessity and not because they were better or more fun. It's like maintaining an old car, the only ones who think it would be fun are those who never had to continuously do it. Mixing paint shades from a few basic colors is way easier than making paint from scratch. If Thornburg was alive and modeling today he's be using Star paint or Tamiya and not even be thinking about manufacturing his own.He was progressive not regressive....DaveBranum

Mixing Paint

Ken,

I recall reading somewhere that Floquil paint ground there paint pigment much finer than any other paint manufacturer. This is one reason Floquil did such a good job of not obliterating very small detail such as rivets on plastic kits. This could be why Mel used those combinations of ingredients to make his own paint. So I would have to say that you would need to get the powder pigment and mill it to a finer consistency, than say the pigment in a rattle can.

Bernd

Making Paint - Dangerous

Yes you can make your own paint, however it is not an easy process and even worse, it might lead to your demise. You can buy the dry pigments at Arts Supply stores, BUT, many of these pigments are toxic and because they are dry they are easily breathed in and/or absorbed through the skin. You have to take extreme precautions when using them or else you may find yourself dead in a few years.

For the hobbyist the biggest issue is getting a consistent colour from one batch to another. When I paint an oil painting I don't want the colour to be consistent, I deliberately don't mix the colours completely so that there is variation in colour throughout the painting. If I am painting a locomotive or box car, then I do want some consistency in the colour, so a premixed paint is a better choice.

I think people get too hung up on the colour, the real railroads didn't care exactly what shade of boxcar red they used, if it was cheap and did the job then they were happy, if the next batch of paint was a little different in colour, so be it! Especially if you are modeling an older time, and the further back in time you go the worse it gets, paints would have been very inconsistent and would weather very fast. The boxcar painted a few weeks ago probably has already faded compared to one that just came out of the shops today. We tend to forget about the advances made in paints over the years, until relatively recent times you couldn't get any bright colours in outdoor paint that would last in the sunshine, hence the predominate use of colours like Box Car red, which is just a form of Barn red or red oxide (oxides of iron, rust essentially!).

So I would suggest you forget the idea of making your own paint and give some of the brands like Vellejo a try and ignore whatever the name says on the bottle, just find a colour that looks good to you.

Brent

DIY Paint

Maybe. You are correct about concern for ingredient compatibility. Furthermore, they may not be complimentary i.e. no advantage to combining them. You definitely don't need the linseed oil. It is a very old organic binder drying oil. The oil paint you buy already has a binder, most likely a long oil alkyd. Linseed oil is best used stand alone such as in finishing fine furniture or musical instruments. It will polymerize to form a film but is incredibly slow at doing so. That is why it is always used in a very thin film application - hand rubbing into hardwood being the most popular.

All oil paints are naturally slow drying. Dryers such as cobalt are added to speed up oxidation for faster dry times. Homemade oil paint is likely to be very, very slow drying. Japan dryer is a consumer available cobalt drier that may help.

Coverage (hiding) is a function of pigment loading. More pigment = more hiding. There is a limit to how much pigment you can add to any given binder (drying oil). Every pigment particle you add requires wetting by the binder. This wetting uses up some of the binder's gluing property leaving less to provide adhesion to the substrate and cohesion of the film. It is a trade-off. Too little pigment and the paint will require many coats to achieve hiding. Too much pigment and you will have a paint that will not stick to anything and will crack easily. The maximum pigment load a binder can support is defined by its CPV rating - Critical Pigment Volume. You will have no way of knowing the CPV of your homemade binder so it is best to keep the pigment volume low. Hiding will not be stellar in homemade paint.

Flow through an airbrush is a function of viscosity. Add enough thinner and any paint will spray through an airbrush. Likewise, adding thinner will result in less final paint film thickness.

Refer to the coverage comment above.

Yes. Polyurethane varnish would be a vast improvement over linseed oil or alkyd varnish in creating your own paint. Single component consumer polyurethanes are cured by moisture in the air. Expect the curing time to be directly related to the humidity level. An even better alternative for hobby applications would be solvent borne acrylic clear coat. It dries by solvent evaporation so is fast dry. You could stir in pigment and have an excellent homemade paint.

Wouldn't recommend you mess with waterborne. Too many pigment/water undesired reactions to contend with. Waterborne paint formulation is much more of a finicky process than solventborne paint formulation. Pigments intended for waterborne formulations are often surface treated so they are compatible with water. Even the acrylic or urethane binders used in waterborne paint are not by nature compatible with water. Acrylic/urethane resins need a special treatment so they can be suspended in water. For homemade paint anything more robust than whitewash, stick with solventborne binders.

Try this on for size:

Create Binder
Place clear acrylic beads (from a craft store) in a glass jar with a small amount of toluene, xylene, or MEK. After the beads melt add additional beads or solvent to achieve a honey viscosity.

Prepare Pigment Dispersion
Using a small amount of the binder you just created, add solvent until the mixture is water thin. Slowly add dry artists pigment stirring vigorously and constantly. Add pigment until you detect a slight increase in viscosity.

Blending
Slowly stir your newly created pigment dispersion into the binder from step 1. Add very small amounts of solvent periodically as you add the pigment dispersion. The solvent in the pigment dispersion should be doing most of the binder thinning. It will be a slow process, be patient and keep stirring. When finished the viscosity should be similar to pancake batter.

Additive
Put in a single drop of silicone lubricant for each ounce of paint. Stir vigorously.

Filter
Strain the resulting mixture through a fine mesh (women's panty hose) to remove agglomerated pigment.

Application
Brush on or thin with solvent to a sprayable viscosity and spray through airbrush. Apply in thin coats. Paint will be very fast dry.

Congratulations! You just spent the afternoon making a very poor replacement for what you could have easily purchased in a little bottle at the hobby shop.

Paint pigments

Alan,

Are the pigments used to tint paint at the store any good for modeling? I have 2oz bottles of each color.

Can I make my own custom colors using flat white modeling paint and these pigments to color ? I want to be able to airbrush some of it.

Thanks

Randy

I knew you'd chime in, Alan

And I'm glad you did.  The process you describe is intriguing, since I'd never even imagined that you could make paint from scratch like that.  I was just thinking of mixing paint from readily available paint-like products.

So it sounds like the concept is viable, but not really worthwhile except as an interesting academic exercise.

Very likely yes

I don't see any reason why not, as long as they are universal pigment dispersions which most big box stores use (store mixes latex interior house paint and exterior oil paints on the same tinting machine). Common as dirt in the paint biz. How well you disperse them in the modeling paint will make the difference. Stir, stir, and stir some more. Notice the long paint shaker times they use at Home Depot and Lowes? There is a good reason why they do that.

Even a caveman can do it

The whole binder pigment solvent making your own paint thing was figured out a long time ago. 

Even a caveman can do it

and a bit later they mined their own brass but then it becomes a different hobby....DaveBranum