In my very recent thread about gloss coating for decaying, Jim Bernier mentioned that allowing the paint to dry prior to clear coating was important. As I sometimes want to “cram” a lot of bench work (including prep and painting) into leisure time on weekends- or just get to the point where a project has been sitting on the bench for a while and I get “antsy” to finish it and move on to the next one, here is a question: Although airbrushing creates an apparently dry paint surface soon after completion, how long should a person wait to allow the paint to “cure”? Some things I have observed in this regard, relevant to the question asked: - a spray can application of a flat primer such as Walmart color mate gray, is dry to the touch in less than 5 minutes. - an airbrush application of acrylic paint appears dry even faster than that! - a gloss color paint application dries in 24 hrs, but appears to be still delicate to the touch. - Krylon clear coat gloss appears dry to the touch within 30 minutes, but when I use it on decal paper, to “seal” the printed decals, I coat heavily, as instructed, and it takes a 24 hr period for that particular spray to cure. - Dull Cote ( the Testors product) dries to the touch in 5 minutes, but is it cured??? Given the variability of these different applications, are there some general guidelines for curing times??? Cedarwoodron
I use a lot of Polly Scale acrylic paints which dries rather quickly still,I prefer to let the paint cure 24 hours before decaling or assembling the structure.
However and IMHO with Polly S acrylic paint quick drying time 24 hours seems to be a “old school” thing I clung to over the years.
Most people say 24 hours, but that is subject to temperature, humidity, etc. Best bet is to wait until you (or someone who has a good nose) can’t smell the paint anymore. This makes sense to me because the solvent is all gone, leaving only the (hopefully unscented pigment behind-or else we might have a scratch-and-sniff model. lol)
If I’m working on something not that important, I’ll try to push the cure time too. Usually it turns out ok, but I’m not talking about contest quality models. For weathering, sometimes I don’t mind the strange finish that might be the result of pushing drying times. Only once have I stripped the paint off and started over; it turned out fine after repainting and waiting for the paint to cure (24 hours). You might be able to rush the drying a bit if you have the model in a place that has a slightly higher temp and good airflow; but be careful dust doesn’t settle on your finish (because of a strong wind), that will ruin the finish too.
When I was younger, I made a ‘dry box’. Simply a large box with a couple holes cut into it and placed that over a heat register in my house. Hot air would blow in, swirl around the model and exit the vent holes. This only works in cooler weather and it would make the house smell like the paint, which I didn’t mind…but my mom didn’t like it much.
It’s not a race. The more I slow down, the more I enjoy my modeling.
I guess a 24 hr minimum hiatus (or more) between painting and applying decals is a good base timeframe; on the subject of good noses, would my poodle qualify? Thanks, Cedarwoodron
Ron,
Take your time. Yes, Polly Scale does dry quick - But I would never mask to do another color without waiting at least 24 hours. As others have mentioned, let your nose do the ‘sniff test’ to see if the smell is gone! With Scalecoat paint, it could take up to 72 hours before the small was gone. I had on old portable hair dryer I got from my Mother - I threw away the head cover, and ran the hose into cardboard box with a small piece of filter material in front of the hose. I could ‘power dry’ Scalecoat in about 4 hours.
That said, I have clear coated with gloss within a couple of hours with Polly Scale - Then waited another day before doing any decal work. I usually ‘fleet’ my paint work. For example, right now I have 4 MDC 30’ flat cars that have been re-detailed, a ‘peek-a-boo’ gon, a 65’ mill gon and a 48’ GBS gon that are just about ready to get oxide red paint, and then a gloss clear-coat. I will not even start the decal work until at least Monday.
In the meantime, I have a Wilson reefer, a Ohio Seamless gon, and an old Revell MOW/track cleaning car that are getting re-built. They are the priority projects right now. The flats/gons that are getting oxide red just went through the warm soap/rinse cycle and are drying - They will get shot in the morning with oxide red, and get the gloss coat sometime Sunday.
Well, I have to finish up that Ohio Seamless gondola - The ‘tear down’ of the old Varney car is complete. I have to install new metal stirrup steps, and fabricate a new overhead I-Beam for lifting steel tubing, then the yellow paint work can start - I would like to have it complete for the Prairie Lakes Division meet on April 20th.
Jim
Thanks, Jim- as I mentioned, I sometimes have a project sitting around too long and want to speed things up to move on to the NEXT project I will also leave half-done for a while. Perspective from other modelers helps a lot. Cedarwoodron