I have an old post vise which belonged to my Great Grandfather, so it is very dear to my heart. It has a stripped screw, and I want to restore and use it. While I have done alot of metal fabrication, tig and mig welding, I am new to the blacksmith scene. Anyway. I took the bell side of the screw to a machinist and had the old threads cut off in a lathe. I then had a new male screw made, with the same pitch thread as original, but a slightly fatter diameter to account for the metal lost in removing the female threads. I wrapped a length of 1/8 keystock around my new screw, and have a perfect spiral. My plan now is to use a thin layer of .007 brass shim material around my keystock spiral, and insert it into the tube portion of the bell and heat to melt the brass, brazing the keystock spiral in place so as to form the female thread portion of the screw.
Things I am not so sure about yet, as I really dont want to screw up great grandaddy's vise:
Fluxing-yes, or no-seems like it will take up some of the space needed to fit the keystock spiral and brass sleeve into the tube, and it is already a tight fit. Also flux type-borax powder or some liquid would take less space in the bell tube.
Also temper of the metal, after I braze this spiral in place, should I quench, or does anyone have any reccomendations. Also another concern- the keystock may expand upon heating throwing it out of kilter with my already cut male thread. I thought about drilling some holes in the tube and carefully tig welding the keystock in place. Also I dont really have a real forge. I have oxy acetelyne torch and also a homade propane jet burner which I have melted brass in a pot with before. I would proably use the propane jet burner to heat the bell. Will I mess up the bell by not heating in an oxygen free forge?
Thanks for any suggestions.
