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HCl resistant coating for steel structures

2006

Dear sir,
we are a company based in India manufacturing G.I Pipes.
The process requires a acid bath by HCl of pipes before galvanising.The HCl used is usually of 35% strength and because the bath is open ,the acid vapor heavily corrodes the steel shed above. Please guide us with a appropriate coating to increase shed life.
Thanks Regard,

Romil Agarwal
Advance Steel Tubes - Delhi, INDIA

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2006

Hi Romil,

I've come across this before and had replied ... but forgot what the 'number' was.

Back in the 60's. the chlorate mfg. plant of ERCO had this problem. They tried out all the paints...even the expensive vinyl ones ... but their roof was being attacked from the inside, just like yours.

They came up with a super low cost material ... Asphalt, tar, macadam, bitumin. which essentially is the same thing.

Then in Montreal I had to vent some piping for hot sulfuric fumes... but some of the ducting which had to be PP went outdoors but the then available PP was not U.V. stabilized. So I coated it with asphalt. This was also in the 60's.

Then many, many years later someone complained about someone using tar on plastic ducting ! Guilty, I said ... which proves that it sure worked out UV-wise, too.

Freeman Newton [deceased]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).

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Hi Mr. Newton,

We are facing the same problem for the 40% HCl Bath with 80 °C Temp. The SS trays are being damaged. Now we are thinking about Teflon Coating on the Trays.

DIBYENDU PRAKASH MONDAL
- Kharagpur, India
January 9, 2008