The FAL Files  

Go Back   The FAL Files > Weapons Discussion > Gunsmithing & Build It Yourself

Notices

Reply
 
Thread Tools Display Modes
Old November 15, 2017, 12:02   #1
TraFALgar
Registered
 
TraFALgar's Avatar
 
FALaholic #: 4366
Join Date: Oct 2001
Location: Mississippi
Posts: 297
Red face Troubleshooting: Parkerizing WTF moment

I tried parkerizing yesterday for the first time with a very unexpected result! The park pan "blew off" the burner & spilled the entire batch.
Has anything like that ever happened to you?

Long story: I bought a ShooterSolutions park kit a couple of years ago and just got around to using it (too many other projects, I guess). For the park pan I used a stainless steam table pan (~5 qts. capacity). I mixed & seasoned the park solution with powdered iron at <140°F.
Used one of those cheapo Chinese 2-burner propane stoves for a heat source. Set it up on a table in backyard, but had to run very low flame using one burner and monitor constantly to maintain temp < 205° for parking.
I read not to let parts rest on bottom of park tank, so I used two short pcs of 3/8 "stainless" rod as spacers. (Here's possibly my 1st mistake) I thought it was stainless but realized later it was shiny, tool steel drill rod.
The 1st part to be parked was an AKM receiver blank that had been degreased in warm TSP solution, rinsed in hot tap water, & dipped in lacquer thinner for good measure. It went straight from lacquer thinner to 200° park solution. Fizzing started as expected and pretty much stopped after 10 min. I took it out & placed in boiling water tank on 2nd burner. Turned down flame under park tank & covered. So far everything seemed to be working as advertised.
At this point, I went to prep another part. Returned to find burner had gone out & park temp was ~150°. Solution was much "clearer" than before, and there was a thick layer of flocking covering the rods at the bottom. Re-lit burner & closely monitored temp to get it back to 190°.
When I turned aside (literally) to put down the thermometer and pick up the next part, I heard a "thud"/splash noise and looked around to see that the park pan had been dislodged from the burner & had dumped 5 qts. of hot acid solution on the ground, and burners, and table! WTF!
Thankfully, it dumped in the opposite direction, rather than all over me.

Any idea of what happened? Was there some enormous gas eruption in the park solution that knocked the pan off the burner? (5 quarts of liquid ain't exactly lightweight.) Could it have been the propane itself in a "mini" explosion? I'd like to understand this, as I have no wish to repeat this particular outcome!
Oh well, at least I have 2 nicely parked steel rods & a receiver blank.
TraFALgar is online now   Reply With Quote
Old November 15, 2017, 14:22   #2
SAFN49
None
Platinum Contributor
 
FALaholic #: 73015
Join Date: Dec 2013
Location: No Where
Posts: 8,756
Propane is heavier than air so it probably built up in the stove and ignited sometime after you relit the burner.

Why would you put it in hot water after the park? You should put it in cold water to stop the park process.

1 Scrub clean with your choice of cleaner
2 Scrub in flowing cold water
3 Hot water to heat the part up so you don't lower the temp of park solution
4 Cold flowing water to stop park
5 Water displacing oil if you are not going to paint it right away
SAFN49 is offline   Reply With Quote
Old November 15, 2017, 16:39   #3
TraFALgar
Registered
 
TraFALgar's Avatar
 
FALaholic #: 4366
Join Date: Oct 2001
Location: Mississippi
Posts: 297
SAFN49, thanks for your reply. The “stove” is really just 2 cast iron burners hung under a metal frame. There’s no enclosed space for propane to build up in, that I can see. But it’s possible I guess.

About the hot water bath after parking: Brownells instructions say rinse in cold water (as you said). Shooter Solutions garbled instructions don’t specify hot or cold water. FAL file postings by member ‘shlomo ‘ said he used boiling water dip after parking with Shooter Solutions park, followed by oiling with good results.
TraFALgar is online now   Reply With Quote
Old November 15, 2017, 17:04   #4
meltblown
Registered
Bronze Contributor
 
FALaholic #: 34604
Join Date: Feb 2008
Location: SA Tx
Posts: 10,970
Your experience sounds like what would happen to me trying to do the same thing.

Stars and Bars Baby
__________________
Pain is inevitable, suffering is optional.

Expect the worst, and you'll never be disappointed.

Before trying to beat the odds, make sure you can survive the odds beating you.
meltblown is online now   Reply With Quote
Old November 15, 2017, 17:12   #5
TraFALgar
Registered
 
TraFALgar's Avatar
 
FALaholic #: 4366
Join Date: Oct 2001
Location: Mississippi
Posts: 297
Quote:
Originally Posted by meltblown View Post
Your experience sounds like what would happen to me trying to do the same thing.

Stars and Bars Baby
Thanks for your support (I think).
__________________
Government is not reason, it is not eloquence, it is force; like fire, a troublesome servant and a fearful master. - attributed to George Washington
TraFALgar is online now   Reply With Quote
Old November 15, 2017, 22:47   #6
SAFN49
None
Platinum Contributor
 
FALaholic #: 73015
Join Date: Dec 2013
Location: No Where
Posts: 8,756
Here's my 7 tank setup. The heated ultra sonic pre cleaning tank is not shown. The pre dip black is for use with zinc park only.

SAFN49 is offline   Reply With Quote
Old November 16, 2017, 06:55   #7
gunplumber
Arrogant Bastard
Gold Contributor
 
gunplumber's Avatar
 
FALaholic #: 96
Join Date: Jul 2000
Location: Surprise, AZ
Posts: 23,623
Quote:
Originally Posted by SAFN49 View Post
Why would you put it in hot water after the park? You should put it in cold water to stop the park process.
There is no "stop the park process". It stops when it is done.
Or when removed from the tank.

When all surface has phosphate adhered to it, there are no more molecules of the base metal exposed, for the acid to strip an ion off, thereby making it receptive to the free manganese ions to bind.

A hot water rinse is better than a cold water rinse because it will dry faster when you blow the parts off with compressed air. But there is nothing wrong with cold water either.

As to why the tank upset, I have no idea. Your theory doesn't make sense to me. If there was propane gas collected in some crevasse, it would have wooshed immediately on lighting. Not delayed for a minute. And in that minute, it likely would have diluted to the point where it wouldn't ignite.
__________________
T. Mark Graham, Master Gunsmith
Arizona Response Systems, LLC
gunplumber is offline   Reply With Quote
Old December 06, 2017, 15:45   #8
TraFALgar
Registered
 
TraFALgar's Avatar
 
FALaholic #: 4366
Join Date: Oct 2001
Location: Mississippi
Posts: 297
I now have a theory as to how the steam table pan was dislodged.
I tried parking again with a much smaller amount of solution (~20 oz) in the pan over a propane burner. It proved very difficult to maintain a constant temperature below 200° using a candy thermometer & coarse gas adjustments. I think the temp at the bottom of the thin pan gets high enough to cause "micro-boil" (warned about in Shooter Solutions instructions).
Brownells instructions say "Avoid boiling the parkerizing solution. Boiling causes the water to evaporate rapidly, ... and may also induce eruptions of the bath. In my earlier mishap, the small pan was resting (balanced) on the 8 "fingers" of the circular gas burner. If rapid boiling did occur, a large eruption could have sloshed the liquid, causing the pan to become unbalanced and slide off the fingers. (Hey, it could happen! )
TraFALgar is online now   Reply With Quote
Old December 06, 2017, 16:23   #9
CG&L
Registered
Bronze Contributor
 
FALaholic #: 27951
Join Date: Apr 2007
Location: Pine Grove, La.
Posts: 2,152
I don't worry about the boiling thing, it's easy to add water that boils off(steam). I always use distilled water
Never had a micro-boil problem

For a pan to blow off the burner, maybe the thin bottom was concave to begin with and, with heat and expansion, it simply went convex.

Thats kinda the only way something can jump of the stove
__________________
RIP shlomo
CG&L is offline   Reply With Quote
Old December 06, 2017, 17:26   #10
gunplumber
Arrogant Bastard
Gold Contributor
 
gunplumber's Avatar
 
FALaholic #: 96
Join Date: Jul 2000
Location: Surprise, AZ
Posts: 23,623
Quote:
Originally Posted by CG&L View Post
I don't worry about the boiling thing
Then you are spending more money on chemicals than necessary, because boiling rapidly depletes a park solution.
__________________
T. Mark Graham, Master Gunsmith
Arizona Response Systems, LLC
gunplumber is offline   Reply With Quote
Old December 07, 2017, 14:20   #11
jhend170
Registered
Contributor
 
jhend170's Avatar
 
FALaholic #: 76477
Join Date: Sep 2015
Location: Houston, TX
Posts: 1,250
Sounds like you may have hit superheated condition. If everything in the tank is smooth boiling has no place to initiate a bubble (nucleation point, if you need a big sciency word), and you can go above the boiling point on the fluid temps. The moment it finds a point to start a single bubble the entire thing can erupt at once.

Good example of this is the old Mentos in the Diet Coke. Although not heat related the surface of the Mentos is like a tiny golf ball, and gives the CO2 thousands of nucleation points for the gas to bubble and leave the solution. You can also recreate the effect by bringing water (or any liquid really) to a temp above the boiling temp in a microwave in a very (internally) smooth glass vessel. Add anything that can add an imperfection and it too will flash boil. The wife likes her coffee super-hot, and will take it from the pot to the microwave. Occasionally she'll put her Splenda in and it flash boils when the Splenda breaks the surface of the coffee. I have taught her to be careful when doing that.

https://en.wikipedia.org/wiki/Superheating
jhend170 is online now   Reply With Quote
Old Today, 13:01   #12
idsubgun
"Comfortably Numb"
Bronze Contributor
 
idsubgun's Avatar
 
FALaholic #: 3100
Join Date: Apr 2001
Location: In the woods of Missouri
Posts: 10,217
Quote:
Originally Posted by SAFN49 View Post
Here's my 7 tank setup. The heated ultra sonic pre cleaning tank is not shown. The pre dip black is for use with zinc park only.

Well now, I just found my best friend, and only an hour and a half away! lol

Do you have a hot bluing set up as well? I’ve been thinking about setting one up but only if I get my FFL again ( to help pay for it ).
idsubgun is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -5. The time now is 20:31.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
©1998-2015 The FAL Files