f-tube vs ci

[Deleted User]

do f-tubers come with more manufacturing 'debris' in them; ie, metal 'filings', etc? we ended up with some brownish
'scale' in the piping and main 'return' pump, and after i scraped it out to send to a lab for analysis, i decided to put a magnet to it for s&g, and voila!, metal debris

Brad White_185

The manufacturing process is

fraught with opportunity for debris. When fins are stamped, those rounded corners go somewhere... Tubing on the higher quality elements has a slightly over-sized ball bearing rammed through it to expand the tube into the fins.

As with any factory material, an eye inspection is worth doing, air-blow at least if not a hose-out but few have time. I specify that fin-tube in particular be washed with a mild detergent to minimize the "smoke-off" when first heated. Stuff sets off smoke detectors, ask me how I know...