A scratch built Cherry Valley 0-6-0

[nachoman]

Brass models are much easier to strip the paint off if you screw up. Plastic? Well... you can't use nearly as aggressive of a paint stripper, and it is much more of a pain. I've used rattle can primers on metal models before. The red oxide ones are my favorite. Then coat with floquil (engine black should look fine) and then bake.

[eightyeightfan1]

Thats a "Cherry" looking scratchbuild you have there.

[Puddlejumper]

I still have a fading copy of the article he did on an O scale B&O C16a 0-4-0 switcher.

What mag and what month was that? I need some good photos or drawings of the C16a for a project I am doing...

Dave

[Dave Harris sctchbld]

I still have a fading copy of the article he did on an O scale B&O C16a 0-4-0 switcher.

What mag and what month was that? I need some good photos or drawings of the C16a for a project I am doing...

Dave[/quote



You can do a search on either the NMRA site or MR to find the date . Or perhaps Sumpter250 will give you a shout about it. I remember that article & probably have the mag-- in the very back or bottom of a 10 X 30 storasge shed

Dave

[Dave Harris sctchbld]

Brass models are much easier to strip the paint off if you screw up. Plastic? Well... you can't use nearly as aggressive of a paint stripper, and it is much more of a pain. I've used rattle can primers on metal models before. The red oxide ones are my favorite. Then coat with floquil (engine black should look fine) and then bake.

I was thinking about rattle-can primer . I was afraid the pigment would not be finely ground enough & would obscure details, happy to find out it's usuable, I have a new can of gray, guess I'll try it. How long should it be baked & how hot? Do you bake it every coat or after it is completely painted?
Most of my painting has been on buildings or to make junk cars --- neither of those requires a lot of skill-- they don't have to look good-- so to speak.

[e-paw]

I'm building a CNJ 4-8-0 and the valve gear is a real sticking point . I cant find any measured drawings of the valve gear I've tried 3 times by best guessing from photos but have had no luck. do you know if there is a formula to figure out the sizes by wheel diameter or piston stroke or something like that. I hope you could help.[/attachment]    

[nachoman]

I have only baked white metal models. For those models, I remember using red oxide rattle can primer, floquil paint, and then baking the whole thing at about 150-200 degrees in a toaster oven for about half an hour. Definitely don't exceed the melting temperature of your solder, and don't bake any plastic parts. I think I chose between 150 and 200 because 150 is not much warmer than it gets inside a parked car here in arizona in the summertime, and I know automobile engines are painted with hi-temp paint, and they aren't designed to run hotter than about 225. You may try googling the net and find temps that other people have used with model paints.

[tetters]

Question.

How do you bake the paint onto the model? Do you use an old oven or is it something simple like a hair dryer? This is the first time I've ever heard mention of some one baking paint onto model trains before. :oops:

It will fascinating to see how this turns out.

[nachoman]

The basic procedure is to paint the model as usual, then place into an oven to harden the finish. Many things have baked on finishes, from appliances to cars. Something about baking the paint causes it to be harder and more durable. All paints won't work like this - but your typical laquer based paints (floquil) seem to work well.

[Dave Harris sctchbld]

The basic procedure is to paint the model as usual, then place into an oven to harden the finish. Many things have baked on finishes, from appliances to cars. Something about baking the paint causes it to be harder and more durable. All paints won't work like this - but your typical laquer based paints (floquil) seem to work well.

I'm guessing here, but I think the idea of baking paint is to remove as mush of the thinning agents used in paint-- I remember reading that paint takes sometimes years to "cure" & gas off all the solvents . I'll bet that someone here will have the real scoop on this?

[Russ Bellinis]

The basic procedure is to paint the model as usual, then place into an oven to harden the finish. Many things have baked on finishes, from appliances to cars. Something about baking the paint causes it to be harder and more durable. All paints won't work like this - but your typical laquer based paints (floquil) seem to work well.

I'm guessing here, but I think the idea of baking paint is to remove as mush of the thinning agents used in paint-- I remember reading that paint takes sometimes years to "cure" & gas off all the solvents . I'll bet that someone here will have the real scoop on this?

I think you are right on Dave. I suspect that baking is even more effective when you use water based acrylic paints. A friend of mine has been using Badger Model Flex and has found that it sometimes takes weeks to dry completely. He also found out the hard way that when the temps out here go below 70 degrees, the Badger doesn't want to harden at all. He models in plastic, so he can't bake anything.

[Sumpter250]

do you know if there is a formula to figure out the sizes by wheel diameter or piston stroke or something like that. I hope you could help.

Pretty much, all the measurements for valve gear, are based on the stroke of the pistons. I found a CNJ 4-6-0 in MR's cyclopedia Vol I, but no Mammoths (4-8-0).
Typically, the distance from the center of the driver, to the center of the crank pin is equal to half the working stroke of the piston ( overall length of the cylinder, minus the steam port openings ) The eccentric crank, seems to be approximately 1"-2" larger, center to center.
The crosshead is dependent on the diameter of the cylinder, as there has to be space on the back of the cylinder to attach the crosshead guides.
The maximum travel of the valve (and, therefore, the valve gear) would closely match the "working stroke" of the piston.
If you have a photo, and can determine the diameter of the drivers, you should be able to determine the "scale of the photo", and then the relative sizes of the rest of the parts. If you are using the drivers shown in the photo (looks like they're 45" dia), use them as the means of determining relative size, specifically, the distance from the center of the driver, to the center of the crank pin.
Hope that helps,
Pete

[nachoman]

I think you are right on Dave. I suspect that baking is even more effective when you use water based acrylic paints. A friend of mine has been using Badger Model Flex and has found that it sometimes takes weeks to dry completely. He also found out the hard way that when the temps out here go below 70 degrees, the Badger doesn't want to harden at all. He models in plastic, so he can't bake anything.

HA! Temps below 70... :mrgreen: Here in southern arizona, that happens about two months a year. I quit airbrushing acrylics because they dry before they leave the airbrush. But it is true, the working time at temps below 70 is much longer. I have never baked acrylics, so I don't know how well that would work. I have painted plenty with oils, and I have had many paintings that took months to "dry". And when I say "dry" that sometimes means just skinning over so they are no longer gooey. And they can be that way for years.

[e-paw]

Thanks a lot Nachoman, they are 55in drivers with 20x32in cylinders, Stephenson valve gear, and alligator crossheads. I'll do the math and get to work next week.

[Dave Harris sctchbld]

Well ,RATS!!!

I bought a Badger sandblaster a few weeks back to get this engine cleaned up & etched for painting. Set it up today & started blasting the engine . About 5 minutes into doing it, the blasted blaster fell apart!! The nipple pressed into the gun to screw the airline into popped out & a tiny spring flew out to Lord knows where ( I was outside) . When I examined things, I found the plastic where the nipple pressed in was cracked!!
I knew when I bought it that it had been sitting in the LHS for over 10 years, but I never suspected that it would have deteriorated to that extent. I guess I'll have to call Badger Monday & see what, if anything, they will do about it.
If nothing else I'll see if I can get a spring from them & epoxy it together.