recommend me a pickling paste for stainless

[whm_fab]

hi folks,
due to the million different brand out there, i was wondering can someone point me in the direction of a good pickling paste ? up until now i normally hand finish all my welds with stainless bushes and scotchbrite but its becoming too time consuming.
thanks!

 

[Paul.]

Polinox P rapid is as good as any of the traditional pastes, its a red-ish colour so you can see where you have put it,

 

[whm_fab]

thanks Paul, il look it up. have you ever heard of Derustit? name is a bit misleading, only reason i ask is my local place has it, spec sheet on line seems to say all the right things, but as we all know means squat.

http://www.wholesaleweldingsupplies.ie/index.php?route=product/product&product_id=1659&search=paste

 

[Paul.]

Never used it, but apart from the citric based ones which take forever to work they all have pretty much the same ingredients in them, I just like the polinox because of the visibility of it.

 

[whm_fab]

thanks paul

 

[Shox Dr]

Antinox is another product. Nasty stuff.

Always wanted one them there electrickey wand cleaners.

(I've a 6mtr ladder pan rack to build this week, runners @200mm centres)

 

[zeppelin builder]

Avesta do a range of pickling pastes stick to the nitric/hydrochoric stuff. The hdrofluoric is particualary dangerous stuff they dont give you an antidote spray for nothing read all the safety data and take a proffesional approach to PPE

 

[chunkolini]

What is there that is relatively safe and reasonably fast acting?

 

[ronan]

Avesta do a range of pickling pastes stick to the nitric/hydrochoric stuff. The hdrofluoric is particualary dangerous stuff they dont give you an antidote spray for nothing read all the safety data and take a proffesional approach to PPE

We used to use the avesta stuff at work, it had a horrible smell off it and turned you skin yellow if you got it on you. But it really was great at cleaning up stainless welds.

 

[Shox Dr]

What is there that is relatively safe and reasonably fast acting?

I cleaned a set of stainless steel down pipes in cirtic acid, came up very well, but needed soaking

 

[hotrodder]

The electrolytic weld cleaners are fairly cheap & easy things to coble together...

Some of the commercial brands use AC for cleaning as it has less impact on surface finish than DC which electropolishes at the same time. Generalising the systems that use pads are typically higher voltage and lower current than the brush based kit IIRC. Brushes are obviously waaaay better at getting into nooks and crannies than wands with solid heads

Electrolytes are usually either phosphoric or citric based and exist in different strengths for example Surfox-t is a stronger phosphoric solution while Surfox-G is a pH neutral electrolyte that's about 10% phosphoric.
Ensitech do several electrolytes... tb-25 is basically 50% phosphoric acid with the remainder being water and <5% proprietary, tb-30nd is proprietary & citric based and tb-32nd looks to be the holy grail (about as fool and idiot proof as it's possible to get?) http://tigbrush.com/products/brush_fluids/tb_31nd/
http://tigbrush.com/products/brush_fluids/tb_31nd/
Cheap DC power supplies designed for LED lights are available with about the right outputs (12 - 24V DC, 400 - 600ish W), replacement TIG brush heads aren't too spendy https://www.abrasive-systems.co.uk/carbon-filament-brushes-for-tig-brush.html but the really tight can make their own from carbon filament anti static brushes and probably save a little

With the 24V 15A power supply i have straight citric acid is a bit too slow to use by hand unless there's very little heat tint to remove. I mostly use it on small components hung in a bath of the stuff while i have a tea break or whatever. I'd expect it to work a bit faster with phosphoric or a commercial electrolyte that include other ingredients not mentioned in msds sheets. IIRC TIG brush machines are lower voltage higher current so a 12V 40A power supply might work better with a brush and citric

http://www.google.com/patents/WO2013036999A1?cl=en for more in depth stuff about the electrolytes
http://tigbrush.com/Resources/pdf/technical-reports/Waste-Water-Test-Force-10-33524.pdf food safe investigation
http://www.metalscience.com.au/wp-content/uploads/2013/09/Research_Weld-Cleaning-methods.pdf is a fairly old study comparing the corrosion resistance of 'as welded' versus mechanical cleaning, pickling and electrochemically cleaning