Originally Posted By: Fastcompany
I agree looks cast it will need tight welded with cast rods or it can be stick welded. Either way it will be brittle there unless possibly stress relieved by shot peening. The vise will also need pre heated due to it's size to get full penatration. Sand blast the area to be repaired and soak it down in acetone. Literally if you could soak the damged portion in it that would be great at pulling all the old grease and oil out of it. Someone can weld it the better prep you do the better the odds the well will work.
This is a bunch of hogwash. Stress relief is done in industrial ovens; not shot peening. AWS D1.1 Structural Welding Code has a preheat chart depending upon material and thickness. HEAT will remove old grease and oil out of the pieces. Warm it until it smokes, let it cool, repeat if necessary. Oil will cook off at less than 500F, the steel won't begin to stress relieve until about 1100F. Sandblasting will embed Silicon into the material and is not necessary. Some State Highway bridges are welded with 7018; it is NOT brittle unless not properly preheated. The PURPOSE of preheat is not to "get full penetration," it is to broaden and soften the grain structure and make the final product more ductile (less brittle). Depth of penetration is how deep you grind a bevel in order to lay a bead of weld.
AWS has no prequalified welding procedures for full penetration welding without using either backgrinding, backgouging, or a backing bar. The way you obtain a full penetration weld is to deeply grind a 30 degree bevel on both pieces (60 degree) included angle, then weld up the bevel, then turn the piece over and grind or arc gouge into the BACK side until the line of fusion disappears and you are into the first layer of weld material. THEN you weld up the second side, cleaning all slag and wire brushing between passes to assure there is no foreign material other than weld material in the joint.
Per Code, allowable stress on a full penetration weld is the same stress as the base material. That is why industry usually performs X ray or Ultrasonic (volumetric) inspection on full pen welds.
Cast Iron is a different animal:
http://www.lincolnelectric.com/en-us/sup...ron-detail.aspx
Regardless of material involved, this vise is repairable almost to the point of a machinist not being able to tell it was repaired. When a quality weld job is completed, then repaint the vise. The only evidence of a repair will be the grinding marks on the welded area, which could then be sandblasted away and painted.
AWS Certified Welder and Certified Welding Inspector.