|
Post by mackintosh on Jul 6, 2007 19:16:16 GMT
This is probably a silly question but why do we paint the inside of loco frames red sorry vermilion. I can understand the area with the motion work on a Traction engine being red it means don't stick your fingers in here. But on a loco you would have to have been knocked over by it to be able to stick your finger in it so to speak. Lets be fair it takes an awful lot of masking to get the correct result and then nobody can see the result. Or is there a tradition I don't know of? Bob
|
|
|
Post by GeorgeRay on Jul 6, 2007 19:53:13 GMT
I suspect its because many full size locomotives were originally painted that colour. The idea was probably that when going underneath to oil round etc it was easy to see if there was any damage. However in later years when cleaning went by the board it wasn't possible to determine if the inside was red or black aftera few months running.
|
|
steam4ian
Elder Statesman
One good turn deserves another
Posts: 2,069
|
Post by steam4ian on Jul 6, 2007 22:34:48 GMT
G'day Ray, George et al. I can't add much except that the inside of power transformer tanks was also pointed red, more a red oxide colour. The tanks hold the transformer oil so the paint has to be oil resistant. Maybe the red pigment has something to do with oil resistance? Red lead pigment gives a vermilion type shade, this could have been in the pigment. Red lead has incredible coverage power but alas you can't buy it nowadays. Red lead was commonly used as a primer/undercoat, it was in a specification 20 years ago which I changed to sand blasting and zinc rich primer. I guess in these ramblings I may have walked across the answer. WARNING to restorers of old 12"/ft locos: the old paints may contain lead,avoid any form of ingestion.
Related question; the inside of cabs was always painted cream or pale apple green (at least in my part of the world); why not "mushroom" etc?
Regards, Ian
|
|
|
Post by GeorgeRay on Jul 7, 2007 20:28:51 GMT
Ian The Vermillion was not the red lead paint that I was familiar with as a boy, red lead paint had more of a brownish tinge vermillion was a more scarlet colour. However the old paint would almost certainly contain lead. Modern restorations, certainly on the Bluebell Railway, use synthetic paints and where appropriate for locos pre 1948 used to be red inside the frames and were kept clean when I was driving there.
|
|
steam4ian
Elder Statesman
One good turn deserves another
Posts: 2,069
|
Post by steam4ian on Jul 7, 2007 23:37:14 GMT
G'day Ray. Red lead primer in Oz (when it used to be available) was an orange shade almost the other side of vermilion. I actually did some touch up painting on the window frame joints of a house I once owned, the joints didn't open up after that. Iron oxide primers are a deeper shade, haematite red, like dried blood. Spent time as a lad cleaning the muck from between the frames of a Little 2-4-0 which was later to be preserved, it was vermilion between the frames, when you scraped the goo away. One of the preserved locos in SA has red between the frames, being inside valve gear it all looks splendid though in its service life you wouldn't have known. The SAR had one colour for everything. The draw-beams were painted red, the number plates blue in later years and on the larger locos the smoke box fronts were silver. A few locos had the valance skirts in deep green with a silver lining. Cab insides were light apple green with a silver back-head if unclad and black if clad. End of useless information.
I suspect the red pigment used to be red lead, there is something special about the way red lead oxide bonds with linseed oil which makes it a particularly durable coating. Modern primers have titanium dioxide and this has to be treated during manufacture to make it oleo philic when used for paints.
Regards, Ian
|
|
waggy
Statesman
Posts: 744
|
Post by waggy on Jul 8, 2007 15:06:01 GMT
Hi Bob,
I put a very similar question to a retired railway fitter when I first painted the frame of my B1. He told me the red/orange colour made it very easy to see when using a "Duck Lamp" to work under the loco. I suppose the orange light from the paraffin flame reflected well. He also advised that the whole of the inside wasn't painted red, usually just the bit between the cylinder block(s) and the firebox throat. The rest was black.
When I worked at Newton Heath depot we had a batch of Leyland 680/1 DMU engines from the repairer, these were painted red. When you crawled over the top to connect up, the red did make it very easy to see.
Waggy.
|
|
|
Post by mackintosh on Jul 8, 2007 16:51:45 GMT
Thanks Waggy this seams the most plausible reason so far. I thought there would have been a definitive answer to this one. Just shows how wrong you can be. Bob
|
|
|
Post by Deleted on Jul 8, 2007 20:17:53 GMT
Many years ago I seem to remember reading that the inside of the frames of early loco's were painted red so that it was easier to spot any cracking of the frames. A crack would gather an ingress of dirt and oil which would then show as a black line against the red frames. Might be wrong of course, but it seems plausible to me.
|
|
steam4ian
Elder Statesman
One good turn deserves another
Posts: 2,069
|
Post by steam4ian on Jul 8, 2007 21:37:02 GMT
G'day Val. Your answer seems logical, instant die penetration test. The loco needed to be clean for it to work, not always so in practice.
For the lighting reasons cited the colour could have been white, cream or yellow. I'll stick to red lead as being the most durable of the possible coatings. Red lead coatings were frequently used as primers anyway.
Regards, Ian
|
|