Green olive drab ph will not rise?? why??

[MrPontiac]

My ph on my olive drab is at 1.6, after talking to guys at Caswell i was told to ad no.2 witch is formic acid to it gradually to increase ph level to 2.2 to 2.7
witch is the best ph level, started with 1/4 bottle nothing happened then 1/2 bottle went to 1.8 then i added whole bottle and it only 1.9, whats going on?? searching for answers, please help, yes im using distilled water, exactly 2 gallons.

[KCV6]

What percentage formic is the solution you are adding (i.e 10%, 30%)? Also what size bottle? Does not sound right to me at all. I would have thought adding formic acid would make the solution more acidic and therefore drop the PH. Lower PH number = more acidic, Higher PH number = more Alkaline.

I don't do olive drab as yet, but my silver and gold I PH ballance (lower the PH number) with nitric acid to 1.2 - 1.8. These are ambient operating trivalent chromates. Very user friendly.

[MrPontiac]

Ill have to check the bottle, its what green drab comes with, it says formic acid on it, 8 0z. bottle, is all it says??

[KCV6]

Yep, OK 8 oz is not a lot of acid as I suspect it is fairly diluted anyway.

Right next problem... if you add acid to any solution it will cause the PH number to go down. In your example you are trying to go from 1.6 up to 2.2 to 2.7. adding acid should make the PH number go down not up? What PH meter are you using and is it setup properly?

Unless I am missing something here I can not see why the olive drab would be doing the opposite.

Try putting about a cup of the solution into a small container and start adding distilled water to it. keep checking the Ph and see which direction it goes. My guess is it will go more alkaline as in the PH number will increase. If you can get it around 2.5, try dipping a zinc item in it and see what happens.

To be honest, I understand your frustration. If you purchased the olive drab and did exactly what the instructions said, it should have worked. Judging by your posts it doesn't and never did. I suggest you tell Caswell to replace the chemicals as something ain't right. Adding acid is not right in my opinion. It is simple chemistry. The mix is good, it should work every time.

My 2 bobs worth.

Cheers

Mark

[MrPontiac]

i am on my 2 nd. set they sent me, i also bought there very own ph tester and recieved in the mail today there solutions for testing the meter, i was off .2 on the meter and adj. it. my green olive drab is now at .2, wish it would go a little higher but im going to try what you said. Wish me luck!!

[MrPontiac]

Well after trying no less than 12 times this product just does not work for me, period!! glassbead a part, de greese it, etch it, wash off with distilled water then plate it for 25 min. set it in green drab solution, turns brown instead of green, wish this product worked like there yellow cad solution, its a snap. Please work on the solution caswell before i go bunkers!!

[KCV6]

There still has to be something else wrong or missing here. Chromates are chromates weather they come from Caswell or any other supplier. If it is just standard Olive drab chromate then it should work. I still don't understand the adding acid to get the PH to go up? As I said earlier, the more acidic a solution is the lower the PH number goes, you only add acid if you want the ph to go down. 0.2 is way too acidic. With any overly acidic chromate solution regardless of if it is gold, silver or olive drab, the items will come out blackish brown. A poor mans black chromate is to take old spent gold chromate and add hydroclauric acid to it to blacken the zinc as the chromate goes on (and for heavens sake no one try this as it will screw the solution).

Cheers

Mark

[craige]

Your pH should be 1.8 - 3.3. The optimum pH is between 2.0 and 2.7 and is maintained by adding equal increments of Part A and Part B to the solution. . Do not mix Part A with Part B when replenishing solutions. Part A contains chromium compounds and is an acidic solution. Part B is an acidic solution.

[MrPontiac]

Well 13 and 14 th time with the small accelerator arms, caduim plated for 20 min at 90 degree temps. absolutely solid brown color non green, wish it worked like the yellow chromate solution, breeze, been fighting it for days just will not work, period.

[KCV6]

Your solution is way too acidic so it won't work.