Brass scupper tubes question

[Bushwacker]

Originally Posted by FLexpat

. . . McMaster has 1-1/4 brass tube but I'm not sure if it is a marine alloy so I decided to add some 316 stainless to a recent buy and try it - maybe several times before I get it right. . .

If you ever get any leaks and the wood block gets wet around a stainless tube, you'll have the perfect conditions for crevice corrosion, due to moisture + lack of oxygen. The stainless might not be much better than brass in that situation!