I have finally finished practicing my painting skills on old freight and passenger cars rolling stock and have now advanced to painting some of my steam engines.
My first candidates were a couple of brass engines that had terrible paint applications.
There is no doubt that old that these engines were never prepared for painting and were the victims of brushed on applications. In some cases very thickly applied.
As I posted recently I bought a blasting cabinet and have been practicing removing paint on a few old brass engines as well as preparing a few new brass engines for painting. I have been using a Badger mini-spray gun and a very fine aluminum oxide abrasive as well as using baking soda.
Having now used both, I much prefer the aluminum oxide abrasive. I was very pleased to find that it is extremely recyclable, there is very little waste with it, I just keep running it through a fine strainer and that seems to catch most of the flaked paint that was on the various engines.
Does anyone bake their brass engines after they have painted them?
What other methods of hardening fresh paint are there?
If you are using Scalecoat 1 paint then it is recommended that an oven cure should be used. I just finished my first brass paint job and am very happy of the results. I used Scalecoat 1 mainly for the gloss finish for decaling without adding a gloss coat. http://s1081.photobucket.com/user/locoi1sa/library/K5s%205698%20project?page=1
For plastic I used regular old pollyscale or even some testors. Plastic is not baked on for obvious reasons so an acrylic paint is used.
Well I don’t know if it makes a difference, but all my paint jobs are Scalecoat or Scalecoat II, and even my plastic items get a minute under a hair dryer after they are dry to the touch, then they set for about 3 days before any other work is done.
All my paint jobs have held up well, so maybe the hair dryer makes a difference.
I don’t paint much brass, because I don’t buy much brass, but on the little I have my results have been fine without putting then in the oven.
Baking brass models painted with Scalecoat I was pretty much standard practice. Scalecoat takes forever to completely dry/cure. Some folks say that the finish gets very smooth after baking. Back when I was painting a lot of brass engines, I found these items:
You need a well regulated oven heat - Let it warm up first to get rid of the high tems of start up. I modern convection oven with a digital heat control is perfect. An oven-proof thermometer that is large enough to ‘see’ is a good investment.
Be very careful of ‘weights’ in the engines. Many times they are a low melting point metal and can ‘run’ out of the model while it is baking!
For plastic models I made a dryer box out of an old used hair dryer and a cardboard box. Worked good when ‘power’ drying a plastic model before masking for the next color.
Virtually all of my own personal model paint is done with acrylics now. They dry super fast and adhere quite well. With you Badger mini-blaster, you should be getting a good ‘tooth’ on the metal for paint application. I use the mini-blaster with baking soda to ‘erase’ old paint/lettering on plastic models.
Baking of acrylics is not good for long term (not something model railroaders generally need to deal with unless you expect the paint job to last 30 years or more). The biggest mistake people make when dealing with acrylics is they treat them like the solvent based type which set up as the solvent leaves. Acrylics cure over time and if thick enough can take years to cure (some art painters have learned this the hard way but we don’t paint that thick).
Wow, 220 grit. If that’s the same 220 grit we used when I worked on large turbine-generators, 220 grit was what the blasters used to clean scale and other build up off turbine rotors. Don’t want to be lingering too long in any one place. You’ll just eat away any thin metal sections.
It is the pressure that really determines the amount of abrasion that occurs.
I am using a setting of 25 psi. When I tried baking soda I found the baking soda actually did a slightly better job however it really creates a mess and it really fogs up the blast cabinet.
I bake everything in my homemade “light bulb” oven. My oven is large enough for O scale passenger cars, but can be scaled down for one HO engin and has 3 100W lightbulbs with a dimmer to adjust it from 0’ to 175’. Plastic engines are baked around 125’-150’, brass at 175’. Acrylic paints get baked for about one hour to fully cure the paint, solvent paints get baked about 2 - 4 hours. depending on whether it’s brass or plastic. The oven is easy to build out of scrap lumber and some chicken wire. I have a set of plans if anyone is interested.
I have a 1965-era brass Tenshodo GN S-1 4-8-4 that was stored for a number of years and the packaging foam decomposed, stuck to everything and caused the factory paint job to blister. I didn’t follow ANY of the procedures outlined in this thread, but the outcome rivals that of a factory painted locomotive. Seeing the absolute mess in the box almost made me throw up, but I perservered and went to the local paint store and bought a can of commercial paint stripper. It made a horrible mess, but the all the paint came off without harming the brass.
I then washed everything with soap and water and let it dry. Having lived in the US all of my life but now retired in Italy, I was partial to Floquil paint, but unable to get it shipped here because of flamabilty issues. I settled on PS Scale paint for the Glacier Park scheme, which I brushed on. I used Humbrol paint (available locally) for the smokebox gray because I could not get smokebox gray from the US. The results were even better than I imagined, as I had airbrushed other brass locos in the past and I cannot tell the difference. After decaling, I bought a can of clear flat spray to seal everything. The results were super, and I plan to repaint several other old brass locos in the same manner.
I have baked the paint on one Mantua steamer, I painted it with primer and baked that per the instructions in the kit. Then, as an experiment, the next metal steamer I built, I simply painted with Flo-Quil paint and did not bake. I found the finish to both to work equally; so, I never baked another paint job.