vinegar percentage?

[happy-diver]

5% or 10% undiluted, 2 mins in microwave then ultrasound or not and keep an eye on your stuff.
Five minutes...So soaked or ten

Phosphoric undiluted cold, five or ten minutes for big stuff eyelets double hose cans etc... Brush on

One more phosphorisation to go

The key is to use nylon or plastic tools to chip or chisel off stubborn lumps without dragging
the removed hard verdigris stuff across your chrome, scratching it like all the dumb arses do

Had to save the Draeger seal transfer ha ha ha ha ha!!!!

 

[Couv]

Phosphoric undiluted cold

I thought phosphoric acid in undiluted form was a solid. Here in the US it is sold in liquid form with the highest concentration being 85%. Some products, like Naval Jelly, combine phosphoric acid with a thickening agent for a more tenacious application ; however the concentration is only 10-30%. If memory serves me correct, Naval Jelly used to be very near 100%, but now for some reason, it's watered down.

 

[kelemvor]

I thought phosphoric acid in undiluted form was a solid. Here in the US it is sold in liquid form with the highest concentration being 85%. Some products, like Naval Jelly, combine phosphoric acid with a thickening agent for a more tenacious application ; however the concentration is only 10-30%. If memory serves me correct, Naval Jelly used to be very near 100%, but now for some reason, it's watered down.

The loctite brand naval jelly (which is what I've seen) says 10-30% phosphoric, but it also contains up to 1% sulfuric acid, up to 1% alcohol, and a host of other stuff. 10-30% is quite a range. I wonder why they can't be more specific than that.

It ends up being very acidic with a pH of 1.5-2.5

 

[dberry]

85% phosphoric acid is considered concentrated phosphoric acid. It is essentially "pure", as in you can't make it more concentrated in water without forming polyphosphoric acids or the various anhydrides like P4O10. Pure P4O10 is a solid, but it isn't acidic until mixed with water.

Naval Jelly (rust remover) is (or was) essentially 85% phosphoric acid. 85% is a liquid that is a little viscous (but it pours faster than, for example, honey). It is much better at dissolving rust (iron oxides) than vinegar. I have no personal experience with using it on crud from corroded brass or other metals (verdigris), so I won't opine.

Acid strength is only part of the reason phosphoric acid works well to dissolve rust; the stability and solubility of the iron phosphate plays an important role. (totally off topic: lack of iron phosphate played a significant role in the rise of lead concentrations in the drinking water in Flint, Michigan. https://cen.acs.org/articles/94/i7/Lead-Ended-Flints-Tap-Water.html).

 

[admikar]

Apeks service manual mentions distilled white vinegar, undiluted, which is 9 or 10% around here. I used it 1:1 with distilled water, 3 minutes in ultrasound bath.

Result:

 

[gummybun]

Pure Citric acid in powder form is easy to get in DIY stores that cater to candle and soap making - it gives the 'fizz' in soap bombs and bubbles in soap. Commonly sold in non branded 1 pound and 1kg bags for, like $5 if I recall. That will last you a long long time. I use it regularly to remove calcium buildup on internal coffee/espresso machines I strip down. and occasionally put it (a tablespoon) through my washing machine to keep it fresh smelling without fake chemical smells.

But you do need to be very careful. If you use a mix ratio that is too strong for the task at hand, or a mixture that is too hot (as this affects its effective strength massively) you can eat right through the chrome on the backside while concentrating on the progress of calcium removal on the front. Never leave your work soaking unattended for any length of time. Also Citric can digest some plastics so try to minimize exposure to those parts. You can read more about this on forums catering to Espresso Machines like Home-Barista and Coffee Geek etc. Best practice a bit on some non-critical parts, and don't become complacent - I've found that the hard way!

Remember that the chrome thickness is part of thread tolerance and if you vaporize your chrome your threads will be a bit looser. And while re-choming is not especially expensive, if you eat off the chrome on threads finding a good re-chromer and knowing the number of microns needed to return the thread to spec is not much fun.

 

[W W Meixner]

I often see advices like "soak your gear in vinegar to remove the corrosion", but never saw which exactly vinegar should be used, I assume it is because there is only one type of vinegar solution sold in the US.
but in other countries there are different solutions, like "5% vinegar", "7% vinegar", 10%, 30%, 100% etc. also there are different types of vinegar, e.g. natural made from apples or artificial one.
I feel that different percentages may behave differently on the gear, and high percentages may be even harmful. So which exactly percentage solution should I use?

V...

I use common white household vinegar...purchased at local Canadian grocery store...same vinegar you'd sprinkle on your French Fries...

I soak parts in large coffe mugs...not in solution volumes any larger...earthenware mugs retain heat longer than Tupperware tubs...depending on what I'm cleaning...vinegar/water ratios between 10/90%...to 25/75%...for metal parts...I use hot water from a kettle...and let sit until the solution has dropped down to room temperature...

After-which parts are washed with Crystal Simple Green/tooth brush...fresh water rinse...and thorough drying...

For parts not requiring vinegar pre-cleaning...parts are soaked in Ultrasonic bath...hot water and Crystal Simple Green...10/90% solution...again soak until hot water has reached room temperature...scrub parts with tooth brush...clean water rinse...thorough drying...

This method will clean your parts for 100% oxygen service...providing oxygen compatible lubricants are used...and your assembly location is clean and hydrocarbon free...no grease/oils...or HC based fuels...

Best...

Warren

 

[Externet]

When I had a lot of it, used formic acid diluted to 10% for less than 5 minutes. Then rinse.