Saturday, February 8, 2014

Bad Day at Black Rock Canyon

Why, oh why, oh why did I hurry today ?!!!!!! Powder coating...it's easy...but it is still a form of painting and as such requires proper prep and execution. I choose to do neither today and have paid the piper for it. Arghhhh....

Decided to head to the shop after getting some early morning skiing in. Have been working the rear of the car lately, trying to get the valence, taillights and trim installed. Today I wanted to get the rear taillight buckets media blasted and prepped for installation. I hadn't decided if I was going to powder coat, re-zinc plate or just leave them natural.

I first wanted to see what was under all that dirt and grime - then make the decision afterwards. So swapped out the blast garnet for walnut shells as I didn't want to abrasive-blast the zinc-plated surface if there was a chance I could save it. The first bucket came out great. I couldn't believe how nice it was. I thought, if the other one looks this good, I'll just hit them with some satin-gloss clear powder coat and be assembling them in front the TV  tonight while watching the Olympics. 

But as all things in car restoration, nothing goes as planned. The second was dreadful. Under all that dirt, were a bunch of oxidation patches, deep scratches and discolorations. Always the story with zinc-plated parts. Here you have 2 buckets that have lived their entire lives, just 3 feet away from one another. One is pristine, the other a disaster. What to do? Decided, since the second was unsalvageable surface-wise, there was no reason to not powder coat it argent silver. Not my favorite option but for a part typically hidden from view, I just decided for the sake of efficiency and getting the car done before my wife is 80,  to press forward with that. So back to the blast cabinet - swap in the garnet and go after all the oxidation patches. An hour later, the zinc-plating now obliterated, it didn't look too bad. Cleaned it with solvent, pre-heated it to eliminate any outgassing from the oxidation areas and coated it with argent silver powder. And this is where the train came off the tracks. I typically like to preheat a part to at least 400 deg or a bit higher to get rid of any potential outgassing but the part looked so clean, I only preheated to 150. After a 20 min cure, I pulled it from the oven and was already patting myself on the back for a flawless surface....and then I turned it over. Noooooooo!!!!!!! Blisters all over the backside of the part. Then, like Dennis and his deck lid, God and I had a short, but intense discussion regarding my powder coating technique. Oh fudddggggeeeeee.....


argent silver


blister city




Disgusted but undeterred, I swapped out the silver powder in the gun for satin clear, figuring I might as well  finish the other bucket while the oven was hot. In then end, it was the direction I wanted to go anyway. Long story short, another disappointment. The gloss was uneven and there was a slight yellowish hue to the clear. So 4 hrs in the shop - score 0-2. I cleaned myself up and went home with my tail between my legs. I now have 2 fubar'ed parts coated in impregnable powder coat - totally unusable for the moment.


satin-clear with just a hint of warm yellow :(

I have 2 more spares in the basement, so I might try and media blast them and see where they stand - then pay attention to my prep and execution and get my head out of my butt and focus on what I'm doing. Double fudge....

 

3 comments:

  1. Yousza RJ! I feel your pain. I'm not familiar with power coating, but it can't be media blasted...or in doing so, you risk damaging the part? At least you have two good parts to give it another try. That's two more than I have for my deck lid!

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  2. Probably easier to throw some chemical stripper on it then back into the blast cabinet Dennis. I'll get my mind right and have another go at it this week. 1 forward, 2 back :/

    rj

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  3. In my defense, if you notice, the frame around perimeter of the part is perfect. It is so nice you can see yourself in it. This is what I first saw as it came out of the oven. Then I spotted the blisters. Arghhhh.....so close....so far....

    rj

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