I used old 1" water pipe to build a metal fence and would like to attach some cast iron spear points to the tops. The only one that fits has a solid base and I need to weld or braze or ? Any one know the best way to do this?
Thanks, RO
Not knowing the shape of the bottom of the point, nor how it fits the pipe, I can't give you a really specific answer. If the base of the point has a taper that fits into the pipe, my favorite join is a heat shrink attachment. Heat the pipe to a red-yellow heat to expand it, then tightly insert the tapering point base and immediately quench. You will not have any metals mismatch to cause galvanic action, and it is a very clean looking permanent join, with no unsightly weldment. It would not need to be painted if you don't mind a rust patina.
Brass, copper, or silver brazing works well, and all are very strong, but you will need to paint it for both aesthetic reasons, and to prevent galvanic action between dissimilar metals. Often the flake carbon in the cast iron can make brazing a challenge, but that can be overcome using cleaning techniques to remove the surface carbon. Wire brushing doesn't help.
Welding works fine too using a high nickel rod, but that can cause aesthetic problems due to the bright weldment when you are done if it is left unpainted, so a better choice might be a rod such as Lincoln Ferroweld which will rust along with the steel and the cast iron and form one uniform patina if you don't paint it.
I hope that helps
Ron Reil Golden Age Forge
Thank you. Bob
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