Page 2 of 2 FirstFirst 12
Results 16 to 25 of 25
  1. #16
    Join Date
    Apr 2018
    Location
    Perth
    Posts
    168

    Default

    Quote Originally Posted by matthew_g View Post
    You could try Pickling gel.....
    Avoid pickling paste if you can. You need a licence to buy it and there's a good reason for that ,its dangerous stuff.
    It also changes the appearance of the stainless.

  2. #17
    Join Date
    Aug 2008
    Location
    Melbourne
    Age
    34
    Posts
    1,075

    Default

    Thought I'd look up pickling gel/paste....nitric acid AND hydroflouric acid

    Full hazmat suit, gas mask, decontamination...definitely pass on that one

  3. #18
    Join Date
    Sep 2008
    Location
    Riddells Creek, Vic.
    Posts
    831

    Default

    Quote Originally Posted by Sparksy View Post
    Avoid pickling paste if you can. You need a licence to buy it and there's a good reason for that ,its dangerous stuff.
    It also changes the appearance of the stainless.
    A licence to buy it, are you sure about that? I have never had a problem getting it. unless things have changed in the last year or two.

  4. #19
    Join Date
    Jul 2006
    Location
    Athelstone, SA 5076
    Posts
    4,255

    Default

    Quote Originally Posted by Sparksy View Post
    Avoid pickling paste if you can. You need a licence to buy it and there's a good reason for that ,its dangerous stuff.
    It also changes the appearance of the stainless.
    Is this the stuff you can get off Ebay

    https://www.ebay.com.au/itm/Able-Ino...9-cadbfbd0a253.

  5. #20
    Join Date
    Apr 2018
    Location
    Perth
    Posts
    168

    Default

    Quote Originally Posted by eskimo View Post
    Is this the stuff you can get off Ebay

    https://www.ebay.com.au/itm/Able-Ino...9-cadbfbd0a253.
    Thats the stuff. when I was working we actually couldnt buy the stuff because of the dangerous goods licence and that we were a food manufacturer here in Perth.
    Look at the ingredients, Hydrofluric acid and nitric acid. Hydrofluric will readily enter the body and start eating your bones. And burn the skin.
    Scary to think you can buy it on ebay.

    https://ehs.unc.edu/chemical/hfa/

  6. #21
    Join Date
    Dec 2018
    Location
    NSW
    Posts
    586

    Default

    Quote Originally Posted by Techo1 View Post
    A licence to buy it, are you sure about that? I have never had a problem getting it. unless things have changed in the last year or two.
    It's restricted in WA. Not in NSW, not sure about the other states.
    HF acid melts your skin, then tracks thru the calcium in your bones. Human jellyfish kinda stuff.

  7. #22
    BobL is online now Member: Blue and white apron brigade
    Join Date
    Feb 2006
    Location
    Perth
    Posts
    7,183

    Default

    Quote Originally Posted by Commander_Keen View Post
    It's restricted in WA. Not in NSW, not sure about the other states.
    HF acid melts your skin, then tracks thru the calcium in your bones. Human jellyfish kinda stuff.
    I have had two mild HF acid burns. A drop of concentrated HF must have got through the seams of a double pair of gloves onto to a spot on my right hand between the index and ring finger. I did not notice it until several minutes after when I was exposed (handling 500mL bottles of HF, it was the only acid I handle at the time ) and by then I was out of the lab. It started out as a mild burning sensation and I absentmindedly sucked on the spot (turns out you mouth is relatively safe due to all the Ca++ ions floating around there, the precipitates small amounts of the fluoride ion as CaF2). The pain increase and I then went to the Uni medical centre and they injected the site with a Ca solution and slathered a Ca gel over the site which had now turned red. The pain diminished over about 10 minutes and the only after effect was a loss of a 1c size area of skin around the site. The second exposure was on a finger knuckle of my left hand same problem with Plastic gloves This time I saw it happen and we had a HF first aid treatment pack in teh lab and applied the gel and the went straight to the med centre where they did the injection. Much less pain this time. The absorption of the HF depends on how much oil your skin has built up on it.

    After this we changed the lab protocols and used nitrile rubber glove covered by a tough plastic glove, safety specs replaced by full face shields, and a perspex safety shield. We used to make/distill our own concentrated HF, nitric, perchloric, and HCl acids.

    The nitric is also pretty nasty. The worst one was, unbeknownst to me, a drop of concentrated nitric fell onto my cloth shoe coverall and burned a 5mm diam hole right through the coverall, leather trainers, the sock and the nail of my big toe . This took about 20 minutes and only when it hit flesh did I notice, excruciating pain like someone had poked a red hot needle into my toe.
    The whole nail eventually turned yellow and fell off.

    I also got some acid onto the inside upper arm of my lab coat which soaked through the fabric and burn off an area skin about the size of a 20c piece. It must not have been that concentrated because I don't remember it hurting that much.

    Lots of other acid incidents in 30 odd years.

  8. #23
    Join Date
    Dec 2018
    Location
    NSW
    Posts
    586

    Default

    My time in a lab was limited to uni days. Mainly molecular biochem- working with animal cells, playing with centrifuges, gels, and all the fun serums which are made from cow pancreas, placenta, and aborted fetuses.
    In my experience, it was always a case of 'read the MSDS' which as a 20 y.o. was no fun at all.

    IIRC for HF it is Calcium Gluconate gel. Get a burn and rub it in until you use the whole tube, then hopefully by that time you are in emergency.

  9. #24
    Join Date
    May 2018
    Location
    Brisbane
    Posts
    12

    Default ss steel tarnish

    It’s hard
    All you want to know and more about stainless steel can be found in papers on the sites of the manufacturers of the product.
    Sites like Austral Wright (australwright.com.au) and Silcotek (silcotek.com)
    I know they have good documentation as I have used their product for many years
    Don’t bother with the snake oil merchants. The actual manufacturer of the stuff mostly have good research papers on their products.

    Rain water is acid Been that way since it was invented.
    Unpolluted rain water PH 6.8 – 5.5
    Polluted rain water Maybe down to PH 4
    Extreme pollution Rains sulphuric acid

    Sea water is salty (basic) PH 8.1 8.2 or there about.
    Contains all the halogens. All 5 of them. Some hydrogen sulphide will be floating around also. Comes with the territory.

    Stainless steel isn’t stainless as noticed
    Why does stainless steel tarnish? Clue: Lugi Galvani circa 1780

    You have two options.
    Best option. Learn to love patina. Patina good pretty
    Or
    Clean it off and have a job for life.
    Best way to clean it would be to get a stainless steel cleaning pro in to clean and seal.
    The have all the gear to do the job.

    Can the patina be removed from stainless steel? Phosphoric acid and Acetic Acid is the goto.

    Acetic acids works too by a different reaction.

    Which is best depends. If one doesn’t work well try the other.
    How effective depends on how heavy a layer of patina has to be removed.

    How long before the patina returns? Immediately
    That is how stainless steel works.
    How long before the tarnish returns? Immediately
    Wash down with demineralised water and alcohol (metho) to neutralize the electrolytes and slow the return until the electrolytes are replaced by the sea breeze

    There are coating available to stop the tarnish. There may be on suitable for your situation. Probably a good idea to have a pro do that. A bad application may give grief. All coatings have a life and require maintenance

    Seems like you may have a fair area to cover. Better start soon because you will be there for a long time. You will probably need to get some tooling together to do the job. Doing it all by hand probably wont be fun.. When you finish it will be time to start again.
    Or learn to love patina

    Have fun with that.

    SAM_0913.jpg

  10. #25
    Join Date
    Oct 2008
    Location
    N.W.Tasmania
    Posts
    1,407

    Default

    It may be worth your while investigating electro polishing. That will remove embedded ions which will lead to rust. The trouble is, it will also remove the brushed finish, and you would have to re-do that finish, but perhaps you could do that with scotchbrite say, to avoid contamination with Iron (Fe) ions. I don't think that it will be practical for large areas, but small parts maybe.

Page 2 of 2 FirstFirst 12

Similar Threads

  1. Rust removal by electrolysis
    By 19brendan81 in forum METALWORK GENERAL
    Replies: 42
    Last Post: 8th Sep 2015, 12:40 AM
  2. more rust removal
    By morrisman in forum METALWORK GENERAL
    Replies: 61
    Last Post: 2nd Jan 2015, 01:14 PM
  3. RUST REMOVAL - CLR?
    By jim47 in forum METALWORK GENERAL
    Replies: 10
    Last Post: 26th Sep 2014, 01:29 PM
  4. Rust removal Evapo-Rust
    By neksmerj in forum METALWORK GENERAL
    Replies: 7
    Last Post: 22nd Jul 2012, 01:26 AM
  5. How To: Brushed Stainless Finish
    By Jarh73 in forum WELDING
    Replies: 8
    Last Post: 6th Feb 2012, 08:51 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •