Both of these methods are fine and correct... No right or wrongs, just different chemicals and minor process differences.
Ive used both methods as well as others.
BB's method has the advantage of fast time, ( good when your doing a job for a customer. Also the pickling process slows down rust reformation and etches metal...
Ian's method has ease of use, chemical costs should be lower too.
Both have similar labour content for prep and wash off.
Drawbacks for BB'S Method would be Safety with the hot process...Yes it burns! And as far as im aware we are no longer permitted to use hot caustic cleaning baths in the automotive industry.
For Ians method, Time, and the lack of a surface etch on bare steel causing surface rust, requiring more work to prep before paint.
Other effective cleaning methods are,
Cold caustic or alkaline bath... Slower than Ians Method and no etching.
hydrochloric Acid...Very effective, but to dangerous to heat, burns are severe and inhalation of fumes can be potentially lethal...Safer when diluted to 50% or below.
Phosphoric acid....Safer, slow process, must be fully emersed, slows surface rust as it etches metal.
Sandblasting....safe, easy, fairly quick and no surface rust. Cost can be expensive if setting up.
Bleach and molasses.....Very Very slow,days or weeks, but generally effective.
Liquid flux....cleans copper and brass in seconds
All processes listed cannot be used with aluminium alloys or diecasts as stated.
There are a few more methods requiring joint processes also.
Hydrochloic acid cannot be used on cast iron if repairs are to be carried out.
Both BB's and Ians methods are perfect for the uses they have stated, and very effective.
But most methods are good...If your set up to do them.
Very good for members to see how a process works effectively fellas!
