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Epoxy resistant to HCL

 

I have a bewt which takes copper out of the process before it reaches the sewer. The tank is made of polypro plastic. My question is the tank contains a mixture of liquid of which one is hydracloric acid., this tank has a crack on the side, is there an epoxy on the market that is resistant to HCl ?

Carl Laudansky
- Canada

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Hi Carl,

To answer your question, Yes but No.

Yes, there are epoxies that are HCl resistant. But NO, you sure won't be able to bond/glue/adhere the epoxy to that PP tank.

If you are inventive, if you know something about plastics, if the crack is small and won't get bigger, you could very carefully heat up the PP surface by 4" or so all around that crack and heat fuse some glass woven roving (preferably) or cloth ... and if it fused on properly, then you'd have a basis for applying a patch of epoxy (with glass cloth & mat) or use, for that matter, just a good acid resistant polyester resin which costs less and is easier to apply. The cloth/woven roving should have exposed fibres for getting a mechanical lock/bond. OK?

Another solution is to entirely cover the tank with a fibreglass overlay. Expensive.

Lastly, it seems that something is amiss for your PP to have a crack like that .... old tank exposed to sunlight, perhaps?

Cheapest solution is probably obtaining a new (rotationally moulded) Polyethylene tank as the only advantage that PP has is its higher temperature resistance. If it is outdoors you could get/order a std Pe tank with a black u.v. resistant color for a few bucks more.

...somewhat difficult to really recommend a solution when one doesn't have all the facts, eh? ie. tank size, location, age, sunlight exposure, welded areas (which might well crack if exposed to oxidizers), chemistry ie. surfactants, solvents, etc.

Have fun!

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