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Posted: 2/20/2009 1:24:18 PM EDT
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I did my first park job today! I "think" things turned out OK on the Krink - I'll have to inspect a little closer, but I did manage to get about 15 minutes of bubble time in the solution.
But here is the problem, The solution got a little too hot and now is full of Yellow Floc. My shooters solutions info says that this condition is a permanent separation of the material and it's now phosphoric acid. WTF do I do now? The solution is garbage after one use? I googled some info and read about others filtering the yellow stuff out and re-using - but I'm not sure if it's the same floc or just sludge. How can I neutralize the acid to dispose of it? Baking soda? (I have 5lbs of it on hand for another project...) Help! |
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I have an allegheny arsenal park kit, and they claim to be able to reuse the solution over again. but just like you it never looks good after a bunch of pieces. works great at first, but it never works as good as it is when its fresh the first time.
sometimes if it gets too hot, that will create the flocking, and I have noticed if usually starts right where the heat is applied on the bottom of the pan, and if I move the pan often it does it less. once that crud is on teh pan its a bitch to scrape off too 
other things like contaminated parts, wrong pan(must be stainless) and poor chemicals will cause it also. |
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no, its been my experience that the used solution does not work as well as it did when it was fresh. which only makes sense, it has to degrade somewhat.
try it, you can always use rust remover to take off any halfazzed park. sometimes it depends on the steel quality. for example I noticed my M1 carbine parts park very easily, even in old solution. and they park well even with a homemade solution of phosphoric acid and maganese(from alkaline batteries) |
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Thanks for giving me some confidence with the process.
My first project came out fairly even, but the barrel is much darker than the receiver....by a lot. It looks like I'm going to have to duracoat the entire thing to make it match. I've got a couple other things ready to Park and may try again tomorrow. I'm keeping the solution in a covered stainless tub for now. It seems to work but I'm thinking that long term it would be better to have a tight seal on the lid - and I should use the plastic jug idea. I'll tell you one thing, I'm tired of blasting! |
| Different metal will park differently even if its the reciever and barrel. ie...different heat treatments and so forth. Don't worry about degrading after one use. The solution needs to be beat up a bit the more you park in the same solution the better it will turn out. You can strain the salts or frocking but the big thing is get it up to temp and when you pull the parts out rinse with warm water and use a toothbrush to get all the access salts and such off. DO NOT throw away perfectly good solution after one use. Also I am pretty sure what you see are just salt. Frocking only occures when you get the thing super hot. If the water is evaporating before you finish a batch then its too hot but it can boil and still be just fine. Hope that helps |
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Flock is normal, just strain it out. A cloth in a soup strainer does it for me.
I find my park solutions actually work better after they have been "beaten up" a bit with use. They tend give slightly splotchy results when fresh. When I finish I always add water back to the original level. And every few uses I add a slosh of fresh concetrate to it. Not very scientific, but it does work well for me. If your part is still bubbling after 15 minutes you may have a problem with the acid concentration being too high. That can then acid etch and thin out the steel. I pull parts out after seven minutes if they are still bubbling and then add some more water to thin the mix and dilute the pH back up a bit. The best park I have done, I notice it bubbles for about seven minutes and tapers off near the end. If bubbles don't taper off, you're eating away steel! That's the feel for it I have gotten over the years. |
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Thanks for the help. I parked a couple more items yesterday. Both kits turned out OK but not as dark as I hoped. My solution seems to be working but I can tell it's already weaker.
I've ordered up some more stuff from shooterssolutions so I'll be ready for my Polish kits. One more question for you guys - What kind of mask are you wearing when you park? A filtered respirator? Just want to make sure I'm wearing enough mask! |
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I do mine out on my shop porch on an old camp stove. I always have a breeze running through the porch. So I don't use a mask. I have long pliers and wires I use to hold the parts as i dip them. Just keep your face outta the steam!
But any charcoal filter respirator should work. Do wear safety goggles. |
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No worries. filter, drive on. If you really want the effort of testing the solution, titrate to a 5:1 ratio, but its cheaper to just mix some new solution and add your new solution (instead of just water) when depleted through evaporation and straining.
Two 50ml graduated burettes in appropriate stand. 100 ml conical flask 10 ml pipette .01% Chromic acid 50 ml glass or clear plastic dropper bottle Normal 10 sodium hydroxide reagent grad phenolthalene Bromophenol blue 75% technical grade phosphoric acid sodium bicarbonate or sodium hydroxide )(flake or pearl) Titrating for free acid content: Put 5 drops of phenothalene into 10ml burette of phosphate solution. Add additional drops until solution turns pink and holds color for 15 seconds. Total ml is your free acid number. Titrating for total acid content: Repeat, starting with 5 drops of bromothalene blue. May take 20-30 drops to change color. Total ml is your total acid number. total acid : free acid 4-6:1 5:1 ideal To increase free acid content, add 75% technical grade phosphoric acid, or more of your concentrate. To decrease free acid content, add sodium hydroxide or sodium bicarbonate, or dilute tank with water. Its just not that critical in this application - After years of struggling to make everything "perfect" from a technical standpoint, I found I could buy a gallon of off-the shelf concentrate for less than the labor cost of adjusting a home mix. So now I keep a 5 gallon bucket of solution next to the tank, and I add in water for evaporation a couple times, then ass in solution for evaporation. I've kept the same tank running for months. |
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Quoted:
No worries. filter, drive on. If you really want the effort of testing the solution, titrate to a 5:1 ratio, but its cheaper to just mix some new solution and add your new solution (instead of just water) when depleted through evaporation and straining. Two 50ml graduated burettes in appropriate stand. 100 ml conical flask 10 ml pipette .01% Chromic acid 50 ml glass or clear plastic dropper bottle Normal 10 sodium hydroxide reagent grad phenolthalene Bromophenol blue 75% technical grade phosphoric acid sodium bicarbonate or sodium hydroxide )(flake or pearl) Titrating for free acid content: Put 5 drops of phenothalene into 10ml burette of phosphate solution. Add additional drops until solution turns pink and holds color for 15 seconds. Total ml is your free acid number. Titrating for total acid content: Repeat, starting with 5 drops of bromothalene blue. May take 20-30 drops to change color. Total ml is your total acid number. total acid : free acid 4-6:1 5:1 ideal To increase free acid content, add 75% technical grade phosphoric acid, or more of your concentrate. To decrease free acid content, add sodium hydroxide or sodium bicarbonate, or dilute tank with water. Its just not that critical in this application - After years of struggling to make everything "perfect" from a technical standpoint, I found I could buy a gallon of off-the shelf concentrate for less than the labor cost of adjusting a home mix. So now I keep a 5 gallon bucket of solution next to the tank, and I add in water for evaporation a couple times, then ass in solution for evaporation. I've kept the same tank running for months. Damn man, that has got to hurt  
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That pre-blackener only works on zinc park I believe. Won't help the mag park.
But.... If you are a real masochist for work, hot bluing the mag park finish will blacken it from gray to black. I've done that a number of times here now. My buddy came up with the idea and it worked great. Chemically burns the park black just as it does bare steel! |
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