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Posted: 11/20/2006 9:48:32 AM EDT
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using GK, started the build process on an AK. had a new receiver (global if it matters) I started with. cleaned thuroughly with acetone several times. sanded some rough spots, etc. cleaned repeatedly with liberal amounts of carb cleaner without allowing anything to touch the surface. warmed the metal just a bit (was about 65 outside) with it hanging in front of a shop lamp. sprayed as directed in 2-3 passes. let dry for 30 minutes. repeated, then put in my bbq pit at 300 degrees for about an hour and 15 minutes. *note....I'd heated the pit several times to try and burn off as much goo in there as possible, wasnt smoking when I was curing. allowed to cool for about an hour or so and started assembling. as you can see, with two passes of the safety lever, all of the material flaked off. not just scratched, but chipped. when installing the safet lever, I barely bumped a rivot and knocked the paint off it as well. what in the world did I do wrong? possibly of note, the carrier, etc is very tight in there now (as in wont cycle without help). prior to painting, it was fine. I was under the impression this was thin enough to not cause an issue with this?  any help would be much appreciated. this frustrates me to no end. THANKS |
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With out being able to put my hands on the item I'd guess it was a combination of the cleaner and not blasting the item. Totally clean the surface with a degreaser that wont leave residue, we use trichloroethane. The blast the item with 80 to 120 grit dry mesh media, we use alum oxide. Preheat the item, coat, and cure. Joe |
| Flaking is caused by insufficent surface prep. I have KG'd parts without sand blasting before and it holds up well, not as as good as a nice blasted surface, but well enough for my personal use. I think carb cleaner leave a residue behind. A chlorinated solvent like brake cleaner, gun scrubber, etc... is good. I found that wiping down with a solvent isn't as good a blasting it from a can. Also no lint. |
isnt on something really nice or worth more money...
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If I can make a suggestion. First degrease it by putting it in the oven for an hour at about 150 degrees. This is how I remove cosmoline off of surplus rifle parts. It will melt right off. PUT A DRIP PAN UNDERNEATH THE PARTS!!! Wearing gloves, take it out of the oven and spray degrease it with a non chlorinated break cleaner. Wash the part off in hot soapy water until it runs clear. Then put it back into the oven for an hour. (Note at no point did I say take off the latex gloves. Even bare hands can leave trace amount of oils on the metal surface and cause the KG not to adhere) It should now be degreased even in the tight areas like the trunnion area. Can you tell I've had to degrease alot of surplus guns in my time:) Wearing gloves, you can now take it out of the oven and sand blast with aluminum oxide. The use your compressor to blow the entire rifle to get all the small particles out of the small areas. After that do use the compressor again to go over the gun. You can reparkarize it with something like Kphos at this point. Once that is done put it back in the oven for an hour at 150 degrees. (Take off the gloves now.) Set your painting area up. Connect your airbrush to the compressor. Plan your route from the oven to your painting area. About 15 minutes before you take the parts out of the oven shake the living crap out of KG container for about 10 minutes. This is so everything gets well mixed. As a side note when shaking the can it is a up and down motion. Swirling the can around just moves things down at the bottom. Pour your paint into your airbrush reservoir. Put on your mask. An hour should be up about now. Put on your gloves. Get the parts out of the oven. If they are too hot put them on clean paper towels and carry them quickly to the painting area. Set the part up as you intend to spray it. SPRAY WHILE THE PART IS STILL HOT. You will know almost instantly if you have the part hot enough by seeing that the KG dries almost instantly when it hits the metal. Remember several light passes are better than a single heavy one. Once you have sprayed your items to your satisfaction or the KG putting down a tacky coating, instead of an almost instantly drying one, move it back to the oven. Set the oven to 325 degrees, for best combination of hardness vs flexibility, for a hour. TIPS. 1. Get a oven thermometer the one built into it may be off. 2. Get a 10 pack of latex or nylon gloves. (I found the cotton ones to leave little threads when moving items that are getting tacky) 3. I like to set my compressor to 25 psi for general spraying and 20 for doing the inside of tight spaces. 4. At 25psi you want to spray from about 6-8 inches. 5. At 35 psi you want to spray at 10-12 inches. 6. Reheat your parts If you have to recoat them. You do not want the parts to become tacky. I hope this helps. Joe Fazio at KG is the best at helping a newbie. Except for the spraying this is how I prep my guns for repark or blueing. Degreasing is the key. |
| After sandblasting, blow off the part, DO NOT DEGREASE with Any Cleaner, wear gloves Take out of the Blast Cabinet, Blow off with air then directly to the oven for preheat. I has same problems, I would blast, then degrease with carb cleaner, and it wouldnt stick |
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You can tell the adhesion is bad due to the flaking pattern. Only media basting with glass or alum oxide will prep for max adhesions. Secondly, the safty on an AK is notorious for the tight movement. My Norinco 56S has a mark in the bluing down to the steel from the saftey and it is not even a shooter. |
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