I would NOT put DC over the hydroprint. Any finish can only be as durable as it's weakest layer.
Duracoat quality is all about prepping the surface and layering. Anyone can throw paint on a surface, but it takes some experience and research to do a quality job that will last. I botched some of my earlier practice stuff by not knowing what I was doing, even after spending 2-3 months researching. (They looked nice coming off the hooks, but did not stand the test of time)
Durabake is intended for faster cure times (full cure on regular DC takes a month, by the book), single color jobs, higher temp surfaces, and things that you would never want to remove. It is also an enamel, and does not recquire mixing, where regular DC is an epoxy. I don't have any personal experience with Durabake. I've read it is about as robust, but also harder to work with as far as spotting and running. Also read it is not good for non-metallic surfaces (think warping), and requires a higher level of care in prep for a quality job. Again, no personal experience
As far as pure durability, and looks IMO, if all you want is black: Parking is the way to go. I've done a couple small park jobs, but nothing I would feel comfortable charging people for, unless it is underneath DC. (Park is the recommended primer for DC)
Here is what I could do for ya, if your interested:1. I'll dunk tank it and remove the hydroprint. There is a very good chance that I can get the base color under the print up too. Then we can see what is underneath: there is also a decent chance it is already parked.
1A. If I can't get the base layer up with solvents
(<-very unlikely), I would sandblast it down to see what is underneath. Blasting won't hurt park much, if at all, but can blemish stainless.
2A. If it is parked: Your good to go.
2B. If not: I can DC it for you, or you can take and get it parked. Probably cost about the same either way, and if all you want is black, park is the way to go. The only exception is if it is stainless underneath, then your only option is DC or cerakote.
(I do not do the latter, and it is much more expensive, but it is the cats meow of firearms finishes according to the interwebs)http://www.mwts-training.com/duracoat-finishing
As far as DC gumming up sprayers: I've put about 2 gallons through mine, have not had this problem. I run about 3 cups of acetone through it after every job. Also, if your DC hardener is even slightly yellowish or any thicker (in consistency) than warm maple syrup, DONT USE IT. It will not mix correctly and it will ruin a gun.
As far as doing DC yourself: Go for it, but do a few practice runs first.
-Degrease, heat, inspect, repeat. I use simple green followed by non-chlorinated brake cleaner. Dry with air compressor.
-Handle with gloves after degreasing: your hands have oil on them, and it is annoying as hell to see finger print shaped spots on your first coat.
-Bast it with Alum. Oxide if you can, 120grit Aluminum oxide sandpaper if you can't.
-Remove everything down to park or bare metal.
-Tape carefully, think it through. Playdough is your best friend for those hard to reach places.
-Measure color and hardner carefully, I reccomend syringes. Mix well before spraying.
-Your first coat should look like a dusting. Slow and steady is the name of the game. The color should not start to become occlusive until the 2nd coat, and not fully occlusive until the third.
-WAIT FOR FLASH OFF BETWEEN COATS!!!!!!! (10-20 min)
-Have good lighting, ventilation, and wear a mask, gloves, and eyepro.
-Inspect carefully before calling it quits
-Wait 72hrs before reassembling.
-Wait at least a week before using, preferably a month.
I'm telling you all this assuming this weapon is not a safe queen and that you care about durability. If I am incorrect in these assumptions: save some money and buy a couple cans of krylon and go to town.
