While Cody does a good job covering spray can painting basics, I will take exception with one thing:
He states that he waited one hour between various coats and re-coats (primer- primer- color- color).
I generally wait a day (or more) between the primer coat (one only, if done well) and further color coats.
The reason is that some of the spray can products from various manufacturers (this goes for Krylon, Rustoleum primarily) have different characteristics which can retard the drying time.
For instance, basic primer gray (I use generic Wal Mart brand) or basic flat black may be dry to the touch in one hour; however, I like to give that paint some additional time to settle and complete the “lay-down” and evaporation of residual chemical from the paint surface- hence, waiting 24 hours.
Other gloss types of paint (I frequently use these before decaling, then tone down with DullCote) have different drying times- some are good to go in 24 hours, others retain a tacky feel and require at least 2 days to settle down to the point where they can be handled.
Since this IS a hobby, and not a business with waiting customers, I prefer to wait that additional time to avoid fingermarks on a partially-dried surface, etc.
Also- be careful when masking over recently spray-painted surfaces- even if dry to the touch, putting an adhesive on top may result in subsequent pull-off of the new paint when the masking tape is removed. This is particularly improtant when doing multi-color spray paint jobs, where complete masking of one color is required before applying the second (or third) color.
Cody did say to use primer & topcoat from the same mfg. to avoid problems. The only thing I question is I never use primer on plastic unless something needs filling, and can’t see the value of 2 coats of primer…just covers up details. I only use primer on metal or wood, never had a paint peeling problem.
One hour between coats? Sorry, but I don’t have that kind of patience. 2 minutes with a heat gun works wonders! I do let the model sit a day or 2 after gloss coating in preperation for decals though. David B
I ususally prime a plastic building before final color but not always. I use Walmart primer too and find that it covers well and isn’t as thick as some of the others. I wait about an hour for primer but most colors need a day to get all the fumes/vapors out of the paint and you can tell how much the odor lingers in the trainroom/basement. The main reason for waiting a day to put a second coat on is that the first coat isn’t fully ‘cured’ or dried and a second coat applied too soon will soften the first coat, sometimes causing a problem. I don’t recommend any of the combination primer/finish coat paints or 2X as some are called, as they are too thick and cover fine details. Just my opinion?
OP: Those “2X” spray paints- usually described on the can as a “primer+paint combo”, are great for that old metal patio chair they always show as being the “project”, but on real-sized objects, there is no fine detail to risk being saturated by a thicker coat of paint, so I stay away from those 2X-type sprays- not very HO-scale friendly!
Buying a small Model Master spray can at the hobby store versus a standard-sized spray can at WalMart or a building supply store also is troubling. Even though they may be adapted to scale modeling spray painting (smaller paint particulate size), paying $5.00 for 1/3 the quantity versus that same $5 for much more paint in a standard-sized can is a poor economic choice these days. Krylon and Rustoleum have a wide range of colors (although not the military drabs and such as Model Master) that mimic many railroad colors.
One quick tip- I keep my cans in a plastic milk crate and use a permanent marker to put a purchase date on the can, so I can check for age of the paint (potential for spraying problems). I also make a note as to what railroad color that particular can represents- for future reference.