Where the
world gathers for metal finishing
Q&As since 1989


-----

Tank material for Nitric Stripping

We would like to strip Ni and Cu plated parts at 70% Nitric @ 110 degree F. What type of tank or liner would be recommended?

Jack M. Strunsee, Jr.
Plating shop employee - New Berlin, Wisconsin
2006

---

Some readers have previously said polypro is no good for this oxidizing agent; others said maybe the charts don't recommend it but experience does. I'd probably go with type 316 stainless or a PVC lining.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2006

---

2006

Hi Jack,

The best material, money being no object, is a PVC:frp dual laminate ... others are the highly expensive flurocarbon dual laminates.

You DIDN't give the size of the tank. Heck, it makes one's answers so much easier if one has all the facts.

If it's a smallish tank, say 300 to 500 imp. gallons, there are rotationally moulded rectangular Pe tanks... in which case, get the supplier (Engel rotational moulding process) to add on more 'powder' to get the thickest possible wall, ie. max. 1/2".

I'm not happy, long term, with a flex. PVC lining as there's a good chance that eventually the plasticiser will leach out ... but if this a one shot deal, ah, go to a swimming pool liner supplier and get (various thicknesses are available) your liner from them.

Hope this helps.

The problem with nitric and Pe or PP lies with the welds.
Hence, IF you can use a moulded tank, then NO WELDING ...
just use tank adaptors (bulkhead fittings is another name)

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