Ground question.

Prep Topics, Pre-Treatment Chemicals
Motoguy
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Re: Ground question.

Post by Motoguy » Sat Apr 29, 2017 2:43 am

Used the setup today, for the first time. I was very impressed with the results, though I admit this is also my first time powdercoating. Took a bunch of 3"x3" squares I had cut specifically for test samples and shot them. Solid color, couple of veins, clear. I forgot the veins need a 2nd coat of clear, so I re-shot them cold (they'd been out of the oven for an hour or so). Just hit them with DA, dried off, and applied the clear. I had a bit of trouble getting adhesion until I installed one of the baffles/deflectors on the end of the EW DV gun. With the deflector and careful trigger application at low psi, I got good coverage on the part (using already coated hangers...will use clean ones next time).

A big concern was the ability to clear coat some of the patina items I make. I wasn't sure how the patina would handle the heat. First attempt didn't go good. Parts were in for 20-25 minutes, as I wasn't concerned about over-cooking the powder (by time, not temp). Took the part out, and the clear (Everclear) looks GREAT. Better than the liquid clear I'd been using. However, the extended bake cycle cooked the patina right out of the part. Instead of the different coppers, reds, blues, etc...it all turned into a God-awful yellow/green/gold color. It was a nasty baby-poop gold/yellow, with a wonderful glossy clear. lol

Checking the website of the patina manufacturer (Steel F/X), I found a FAQ discussing applying clear powder over patina. He said to NOT heat soak the part before starting the clock (which I did), do NOT let the part run full cure time (which I did), and do NOT let the part cool in the oven (which I didn't do). His suggestion is basically to have as little heat exposure as possible. No heat soak, no cool down in oven, and pull the part as soon as the powder flows out.

So...made another patina'd part, and tried it. This time I had the oven pre-heated to 400, gave the part a good coat and put it in the oven. I checked at 3 minutes, and it had flowed out. I pulled it, and the part looked great. The clear looks wonderful (again, better than liquid clear I'd been using), and the patina was unaffected. Next time, I'll check it at 2 minutes and see if it looks as good.

All in all, I'm extremely satisfied with the results. If I'm this happy with the EW DV gun, I'm really looking forward to the results with a better gun. We know how plans end up working, but I think I'll shoot for an EZ50 then a box-fed COLO 800 when the budget allows. I'm just amazed at how much faster, easier, cheaper, and better the result is with powder. Edges of interior details/holes are coated, exterior edges (part was cut from 14ga) are coated, etc. None of this "shoot from a half dozen different directions to get paint into the holes/on the edges".

RideIndustries
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Re: Ground question.

Post by RideIndustries » Sat Apr 29, 2017 4:04 am

Motoguy wrote:
So...made another patina'd part, and tried it. This time I had the oven pre-heated to 400, gave the part a good coat and put it in the oven. I checked at 3 minutes, and it had flowed out. I pulled it, and the part looked great. The clear looks wonderful (again, better than liquid clear I'd been using), and the patina was unaffected. Next time, I'll check it at 2 minutes and see if it looks as good.
It may look wonderful but it's not cured. Take a couple of your samples, one fully cured and one that's been pulled once it flowed. It's a destructive test but it'll show you the difference between cured and drastically undercured. Smack each part with a hanging hook or a screwdriver etc. and watch how the undercured powder will chip and flake off.

What kind of parts are you doing that your only concern is what they look like?

Motoguy
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Re: Ground question.

Post by Motoguy » Sat Apr 29, 2017 4:13 am

RideIndustries wrote:It may look wonderful but it's not cured. Take a couple of your samples, one fully cured and one that's been pulled once it flowed. It's a destructive test but it'll show you the difference between cured and drastically undercured. Smack each part with a hanging hook or a screwdriver etc. and watch how the undercured powder will chip and flake off.
Will do. Always good to be educated.
RideIndustries wrote:What kind of parts are you doing that your only concern is what they look like?
These patina'd parts are decorative wall hangers. The patina finish, which limits the time the powder can cure, is the primary selling point. For non-patina'd pieces, I let the cure go full time (veins, solids, etc). As 95% of them are mounted on an interior wall, they only need to look good, and/or offer some UV (fade)/rust protection for the few that end up outside.

Examples:

Image
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duke46
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Re: Ground question.

Post by duke46 » Sat Apr 29, 2017 7:22 am

Well now I know what you are doing. But with what you said about doing a full cure with the clear it is messing up what you had done with the acid and other color chemicals.

Here is a video 18min that would let a guy know what the process is like.

https://steelfxpatinas.com/how-to-videos/" onclick="window.open(this.href);return false;
All I have said is said just for meanness so I don't have to argue with anyone!

http://www.pcitdad.com" onclick="window.open(this.href);return false;

RideIndustries
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Re: Ground question.

Post by RideIndustries » Sat Apr 29, 2017 6:50 pm

Motoguy wrote: These patina'd parts are decorative wall hangers. The patina finish, which limits the time the powder can cure, is the primary selling point. For non-patina'd pieces, I let the cure go full time (veins, solids, etc). As 95% of them are mounted on an interior wall, they only need to look good, and/or offer some UV (fade)/rust protection for the few that end up outside.
You can also just scrape or pick at the coating on the uncured ones to see the effects of undercuring.

Are you sure it's not just the temp that's making the difference and not the time? If a powder states in should be cured at 400 for 10 minutes, it can also be cured around 350 for about 25 to 30 minutes. Glass Clear is listed to cure at 340 so that can be lowered even more. The manufacture's (not resellers) usually have a graph to show the time vs temp for curing. The oven you're using might have an effect on this too, especially if it's a regular household one as they are nowhere near accurate or decent at maintaining a set temp unless controlled by a PID. The parts could be getting a lot hotter than the set oven temp is what I'm getting at.

I'd do more test's to find out exactly at what temp the patina is lost at.

Chrisyeager12

Re: Ground question.

Post by Chrisyeager12 » Wed May 03, 2017 11:57 pm

Hello, Sorry to hear about the Patina mess you're having while clear coating... Have you only used 1 patina product? The only time I get patina to come off from Silver is when I use a MAPP Gas to REMELT the silver into liquid form. Maybe try a different Patina? I could find out the name of the chemicals we use to patina our silver products. Look us up YPS - Yeager's Poured Silver . On the internet, I'll see if our product will help you out with the coating problem, I'll take a infrared temperature when the patina starts to shed from the MAPP Gas.

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