v8landyman
Active Member
25% phosphoric acid is far superior and it will also passivate the surface ready for painting.
Ive just changed non structural ones for stainless - cheap as chips 
mick 1986
Well-Known Member
Where can we purchase that? Surely that % is for “trade/professional” use only?
mick 1986
Well-Known Member
Just done a quick google search. It seems the general public can purchase up to around 45%. Every day is a school day!
v8landyman
Active Member
You can buy 85% phosphoric acid on ebay for about £14/litre. This would make over 3 litres of 25%. I submerge all removed steel parts in 25% overnight. After rinsing they present a grey coating of iron phosphate that inhibits further rusting prior to painting. Although you need to take care with it, phosphoric acid is not a dangerous acid like the main mineral acids, sulfuric and nitric hydrochloric etc.
mick 1986
Well-Known Member
Much appreciated. I will look into this as the vinegar is taking it’s time with the bits I have in there.
Chrisw8
Well-Known Member
Right........
After 2 weeks.......
A quick clean over with wire brush .....
Taaaa daaa
Had one or two lumpy bits of rust still on , but fell off when tapped with hammer.
Not sure if 2 weeks was too long.....calliper metal seemed to have a softness to it as I was wire brushing.
Still, a good experiment.
After 2 weeks.......
A quick clean over with wire brush .....
Taaaa daaa
Had one or two lumpy bits of rust still on , but fell off when tapped with hammer.
Not sure if 2 weeks was too long.....calliper metal seemed to have a softness to it as I was wire brushing.
Still, a good experiment.
