Dealing with typical "Barnacles" on iron drain stack 1

[DAVIDSTECKER]

I am getting ready to try and sell a home and I have the typical rust "barnacles" on the drain stack in the basement.
I have had a couple of plumbers in for different things and when I bring up replacing the stack they keep trying to tell me that if I replace the stack I'll have to bring a bunch of other things "Up to code", which after reading the code is not true. Grand Father clause.
Besides the barnacles, the pipe is very sound and has past a smoke test done by the sewer company.
I am looking for any methods to convert the rust back into a stable material to be sanded off and potentially re-seal any pin hole that may crop up.
Home Depot has a converter but it only appears to come in one gallon jugs and their pretty proud of it.
Any suggestions for other products in more economical sizes?
For the any pin holes I was thinking about an acrylic wood hardener I have used with very good results form Min-wax.
It is a very thin fluid that penetrates deep into the wood.
Please send me your thoughts and suggestions.
Best regards, David

 

[EdStainless]

Either replace it or do nothing.
If you 'touch it up' and it leaks later then it becomes a known defect that you chose to conceal and you are likely liable.
There are 'rust conversion primers' available in any hardware store in smaller cans.
If I was living in the house I would try to touch it up some, but not for sale.

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P.E. Metallurgy, Plymouth Tube

 

[bimr]

If it is exposed, it will be much easier to replace than try anything that you suggested.

Cut the cast iron section, install a PVC stub, and reconnect with Fernco rubber couplings.

How to:

 

[DAVIDSTECKER]

Thank you for the feedback.
I have been trying to get it replaced but every plumber that comes in starts going on about how they need to bring all of the rest of the system "Up to code" when that is not true.
I guess I'll have to educate them.
Thanks again, David

 

[bimr]

Agree with you on that. You can just replace a section, you don't have to replace the entire plumbing system.