I certainly won't argue that point, but my experience as a refiner of precious metals taught me that dilute sulfuric acid won't harm copper, but it has a fierce appetite for copper oxides, which would be commonly found inside a smoke box. Hot concentrated sulfuric acid does dissolve copper.Bill Shields wrote: ↑Thu Apr 07, 2022 12:12 pm Biggest problem with copper tubing in the smoke box is not so much sulfur but abrasion from flying cinders
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