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Well the pictures speak for themselves, but here is the story. I bought some solution online. I mixed it up per instructions and parked my receiver about two weeks ago in a small stainless pan. It came out pretty good. Flashforward to today, I unexpectedly had a day off and haven't ordered a full size stainless pan for my barrel yet. While browsing wally world, I saw one of the silver roasting pans that was just the right size. Well not having much else to do I sandblasted all day then this evening I parked all the parts. These came out disasterous. So I am looking for ideas on what went wrong. The differences between this and last are the pan, one gallon reused solution and one gallon new solution, and lastly I rinsed the parts in water instead of letting them air dry. I rinsed because I read that some people do that and because on my receiver I had some lighter areas that I thought was from letting them air dry.

Thanks in advance for the help.




 

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contaminated solution. There was some oil on the parts. I have seen that before.
 

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Blast media / sand could be contaminated also . Are you reusing the media ? It important to degrease well before blasting and after blasting before parking. Most soultions are very foregiving so you must have had alot of hidden grease when you dropped the parts in the tank. Good luck on the next try. Jerod
 

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I didn't reuse the sand. I boiled the parts with TSP to degrease them. I guess I'll be searching on here for better method of degreasing. At least I can blast and try again. Thanks for the replies guys.
 

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I always degrease with a couple different methods. Whatever you don't get with one you're sure to get with the other. I'll usually do a blast with brake cleaner and then an acetone wipe down just for good measure. The brake cleaner gets into all the nooks and crannies while the acetone wipe gets the leftovers.

One of the things I've noticed is blasting with brake cleaner alone sometimes "moves" the oil/dirt/grease rather than cleaning it off. Wiping with acetone gets all the crap off for good adhesion of Duracoat or Gunkote.

If you boil with TSP, hose the parts down with brake cleaner before you do or wipe them down with acetone after boiling just before you park them.

ETA: It's all about proper preparation. You work your ass off on good prep and that will prevent or eliminate 95% of your potential problems in the finished product.
 

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I like to submerge parts in lacquer thinner. Whatever you use for degreasing, I'd suggest baking the parts in the oven in between degreasing to force any remaing traces of oil out of their hidding places. For instance, I'll bake parts at 200F for about 30 minutes, then scrub down and let soak in lacquer thinner, repeat baking, repeat scrub/soak... keep doing this until no oil shows up after baking.
 

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My guess is there was some kind of crap coated on the new wally world pan. Did you use one of those cheapo roasting pans like you would cook a turkey with? if so its either a coating or the material the pan was made out of. there are many different grades of stainless...if its from wallyworld then it came from China..who knows what they used..could have been made from a recycled 1962 Buick Skylark bumper.......Also you are supposed to rince the parts after the parkerizing bath. if you dont then the solution is still active. parkerizing is mostly acid. Heres how I do it..I have a tank of boiling water next to the park tank & a flowing cold water rinse tank..after the parts come out of solution they go into a cold water rinse. Then into the boiling water. the hot parts will air dry in a matter of seconds without any funky residue.
 

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did you use distilled water?

because some of the water, in different parts of the country is flat out junk !!!

I like to boil the parts in distilled water after degreasing, then put them in the park solution.
 

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blasting

I have been doing Phosphating for 5 years now and 2 for commercial clients. All of the above advise is good. None of them will however solve your problem as shown in the photos. Try blasting with a little coarser media and give the surface a good even light dull glaze. Remove with gloves and phosphate. Please be careful with some of the commercial pre mixes. We have had cases of friends in the busines have serious injuries from inhailing the fumes by accident. I will be glad to P.M. you the basic mix if you need it.
 

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I have been home-parkerizing for a few years and have learned a lot from my failures. All the points mentoned above are valid...

1) Get a little more aggressive with the blasting - you have to get the old
surface patina OFF the metal before the solution will react. (I agree
with 1Woodsman that at first glance this appears to be the problem)
2) Eliminate ANY possible contaminaton of the metal/blast media with oil.
Degrease before and after blasting and handle only with gloves
3) Look out for contamination of the solution with oil - if there was any on
previous parts, it will have boiled off and be sitting on top. Then as
you immerse the new parts in the solution, it will contaminate the part
as it passes through this film. I usually skim off the top inch or so after
the solution has cooled from using.
4) Your soluton may have lost its potency - depending on whose you are
using, this is a possibility. It should be good for multiple uses, but this
will depnd on the solution itself. I seem to remember that there was a
solution that was once being sold as a one-time use only? You could
test it by using PH paper...it should around 2. Some solutions call
for 'priming' the solution initially with a little bit of steel wool? If so,
then once you have done this the first time, the steel should come
from the part being Parkerized itself. Unless you added MORE of
the 'unprimed' solution.

I have used various solutions bought from different vendors....some are better than others, but costly. I finally just started mixing my own by purchasing the raw materials.
 
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