What preferences do folk’s have for painting steam locomotive frames? The frame is going to tend to get real oily and dirty and in the areas near the firebox and cylinders & saddle. How about the cylinder castings themselves? (not worried about the jacketing at this point) Do you bother with hi heat paints for the steam heated areas?

Am again soliciting brand and formula recommendations if you have any.

Greg

Having climbed around inside a few frames, I honestly would be surprsed if there is any paint. I recall a layer of grease, dirt, and ash so thick you would have to chisel it off. That might be different story for a freshly power washed engine destined for display.

Historically Baldwin (and I believe most other builders) painted the frames, cylinders, etc. the same color as the engine/tender... The high temperature areas were either lagged (boilers and cylinders) or coated with a high temp coating like graphite in oil (fire box and smoke box)

So if a loco recieved the common toc green paint the frame (and drivers, and domes, and cab, and tender, etc. was green as well.

Options for restoration would be to ignore the frame as too dirty or steam clean it and treat as any other painted portion of the loco.

I would think you would want to clean it down to bare metal and then primer/top coat black if it's a black engine. If you leave it crusted with years of crap, you have no way of knowing if there are any cracks, etc.

I recommend Dupont Centauri, it is one step below Imron...holds up just about as well, is cheaper with greater coverage per gallon, readily available, is not an "egg shell" finish like Imron thus works better on jackets and things that flex and there is no special gear required to spray it. Like with Imron or any other paints though, multiple coats are required to get the life out of the finish...3-4 is what is recommended for that sort of service enviornment.

What are the rules for time, etc. for 2nd, 3rd coats? The sandblasting, primer and initial top coat are easy to schedule, but I suspect we will want to do additional coats as we remount various pieces of hardware, etc.


Greg

I'd be really careful with the sandblasting, unless all the drivers are out of the frame and everything else is protected. Sand has a way of ingratiating itself into everything it shouldn't.

Abrasive blasting to a "white metal" finish is the most effective way to expose cracks.

Disadvantages:
It creates a huge mess and coats everything nearby with abrasive dust. Blasting with "Black Beauty" (smelter slag) is faster, cleaner, and more efficient than using actual sand. If the frame is covered with lead-based paint (you can bet it is), blast media disposal can cost $250 per 55-gallon drum. Alternatives include sponge blasting to miniimize dust.

Advantages:
Once you reach white metal, you really know what you've got. If in doubt, grind suspicious areas smooth and test with dye penetrant. This allows you to minimize future unpleasant surprises.

Tradeoffs:
You have to look at total cost (including cleanup and disposal) versus the cost of not finding those hidden cracks under the grease, paint, and crud. On 4-6-2 S.P. 2472, our goal was a locomotive that we had absolute maximum confidence in at mainline speeds under full load, so first the running gear was removed, then everything was blasted to white metal. We found and fixed cracks in the main frame top rail (cracked clean through a porous area in the original casting - this weld was so large, we had it heat-treated red-hot to eliminate stress), valve gear hanger bracket, brake cylinder brackets, pilot truck pedestal, etc. etc. This is admittedly a very different standard than many projects could justify, but for us it was a necessary expense.

- Doug Debs