I run into an issue with brass painting. Havent had this issue with brass before. I took this tender that shows its age and tarnish from decades of handling and no cleaning. So I set it in accitone for a little while before scrubbing with a tooth brush, then rinsing to get teh dirt and oils, and such off. let it sit and during the work week came back and hit it with a metal primer. a week or so later painted the light grey letter box on. Polly scale. now it has sat for at least three weeks curing, while waiting for the new electronic guts to arrive. having a lucky soggy day off today, i took the time to mask and paint the rest of the tender. truscale weathered black. immediately remove the mask once the tru scale had sat halfhour. I used timyia masking tape for that mask. when i pulled the mask off it took the grey paint and primer with it in a blotchy pattern . any idea why the primer didnt stick this time?
I have used this process before with no issue. I dont want to move on to the engine itself incase the same situation exists there too.
Shane
A pessimist sees a dark tunnel
An optimist sees the light at the end of the tunnel
A realist sees a frieght train
An engineer sees three idiots standing on the tracks stairing blankly in space
What kind of "metal primer"?
Sheldon
automotive primer
NVSRR automotive primer
Rattle can? Sounds to me like your model was not really clean even though you did all that, and the paint you used was friendly to whatever was still on the model.
I will leave this for others to comment on further, I have no experiance painting models with rattle cans or the brands of paint you mentioned.
I have only used floquil and Scalecoat solvent based paints on my models.
Years of handling may have removed the tooth of the brass (basicaly it has polished the brass). You proubly need a mild acidic action to give back the tooth.
NVSRR I used timyia masking tape for that mask.
I find that Tamiya masking to be a little too aggressive if it is the yellowish stuff in the plastic dispensers. Great product — but I keep in mind just how aggressive it is.
I have several different brands, and even different styles in some brands, of the "delicate surface" tapes. I've had much better luck with mask lines using this kind of tape.
Still, my usual paint for brass (well, styrene, too, on rolling stock) is Scalecoat. Which I hear, sadly, may be going away...
3M tape by Edmund, on Flickr
Sometimes it makes a difference when removing tape to be sure not to pull straight up (tape at a 90° angle) but back on itself so you are pulling at more of an acute angle.
Good Luck, Ed
rrebellYou probably need a mild acidic action to give back the tooth.
Yes... my final prep for brass it a soak in vinegar followed by a rinse of CRC contact cleaner. Then I allow the model to air dry.
-Kevin
Living the dream.
Doesn't CRC contact cleaner also contain a lubricant?
I am thinking the CRC may have left a bit of oily residue
dbduckDoesn't CRC contact cleaner also contain a lubricant?
According to the CRC website, CRC QD Contact Cleaner leaves no residue behind when it dries. This has been my experience when using it during painting preparation.
I will remember that when I go to do the rest of the locomotive. only did the tendeter so FAR. I will etch the rest of it first
My freelance railroad's paint scheme for diesels and passenger cars uses sort of a "two tone" dark blue and light blue scheme. One thing I've gotten in the habit of doing is spraying flat finish before masking.
So like say a streamlined passenger car would be primered, then painted light blue. Then I spray the whole car with flat finish. After that's completely dried, I mask off the lower part of the car and spray the rest dark blue. Sealing in the first color with finish seems to have elininated - or at least greatly reduced - the problem with the masking tape peeling off the underlying paint.
Brass can be finicky. I've tried many primers. Auto primer should work on bare brass. I tried Vallejo acrylic primer and was disappointed with the results. My all-time favorite for brass is diluted shellac (50%, with denatured alcool) applied with a brush.
Simon