Any Tig welders out there.

[Carmel2]

Our holding tank is stainless steel and has a couple of leaks which I suspect has been there from new. I have had it rewelded and tested for leaks, but now someone has said 'oh it will only go again, you'd better replace it with a plastic one'. Is there any truth to this?

 

[pentagram]

no truth in it whaysoever, im a wedler fabricator. sounds like it wasnt welded properly in the first place

 

[Carmel2]

Thank you, my poo should not make a weld fail .............mind you, if tasted my cooking ...

 

[vyv_cox]

Thank you, my poo should not make a weld fail .............mind you, if tasted my cooking ...

Sewage in sea water is a very arduous duty for a welded stainless steel tank. Several manufacturers use this material, amongst them HR I understand, but feedback seems to be that lifetime can be limited.

 

[SpottyDog5]

If correctly welded, the weld is usually the strongest point, as it is often thicker.
Depends why it failed in the first place.

 

[njthake]

I had a stainless tank fitted and heard this was a bad move. I have had no problems after 5 years but it is always a worry and never leave it with a salt water flush for any lengthy period. I always flush through with fresh water asap.

 

[Bobobolinsky]

If correctly welded, the weld is usually the strongest point, as it is often thicker.
Depends why it failed in the first place.

It may be strong, but if the weld has been overheated, the "stainless" elements in the plate are boiled out. Very often that is the first place for the attack and pin holes form along the weld, or along the heat affected zone, one of the reasons why welding wire or rods has higher quantities of alloying elements. As someone said weewee pooh and seawater can be quite corrosive.