brianpgriset
Well-known member
Well I was looking for a smaller vise for my new welding table and found a somewhat rough condition Rock Island 573 on craigslist. It was the right price and size, and I wouldn't feel to bad beating on it. I got it home and started breaking it down. First step was to blast the body.
As I took off layers of thick paint and rust, I found this, much to my horror:
Pretty good size crack on the backside of the body. Someone had also attempted a "repair" on the topside by appearantly arc welding the crack, but did a terrible job. It's cast iron of course. So, not wanting to just toss the thing I started doing some research. It seemed my best bet was to braze repair the crack, but with alot of pre-heat and slow cool to prevent cracking. Brazing seemed to be the best choice, as others at Weldtalk had mentioned since it's properties most closely match those of the base material along with being least likely to cause cracking, of all the joining processes. I had a choice to either fully grind the crack out and fill it back in, or try to draw brass into the crack using a capilary action and try to fill it that way. Personally, I thought the chances of fully grinding the crack out and filling it back in seemed like too much of a gamble, so I went the "fill the crack" route.
I practiced the technique with a lap joint on 1/4 steel, and it worked pretty well.
For the preheat and slow cool I decided to use my charcoal bbq. So I lit it up and placed the body on the rack, waited a good 45 min until well done (haha). Then, with the body still on the grill, I heated the cracked area until red and tried to get the brass to draw into the crack. It was NOT easy getting good positioning on the workpeice, and I had to reposition several times to get the brass to flow where I wanted. It honestly took a good 30 minutes and manipulating and re-working the peice. I do feel pretty good with the repair. At one point I was able to see brass drip from the crack at its tip, deep in the body, leading me to beleive brass made its way through most of the crack.
Once done, I recovered the body and let it sit another 2 hours until it was cooled down quite a bit, probably aroudn 200 degrees. Here is how it looked:
Pretty ugly, but I haven't brazed anything in years. I went forth and started removing the excess brass using a flapper wheel, and to my suprise, got this:
The brass looks like it did exactly what I intended it to do ,flow into and fill the crack. I also feel pretty good the brass made it's way to most of the crack, taking a close inspection of the inside. I seriously doubt I completly filled it the whole way, and I am sure there are still crack tips in the body, but I'm figuring as long as I don't beat the living snot out of it, it'll hold together. Anyways, I stuck it back in the blast cabinet and hit the fresh spots, then hit it with a quick coat of rattle can blue I had around.
All in all, it ain't perfect, but I feel pretty good it'll hold up as long as I don't get too rough with it. Now just need to finish up with the rest and get it mounted. Thought I'd just share if anyone else has a similar issue that wants to try a repair.
As I took off layers of thick paint and rust, I found this, much to my horror:
Pretty good size crack on the backside of the body. Someone had also attempted a "repair" on the topside by appearantly arc welding the crack, but did a terrible job. It's cast iron of course. So, not wanting to just toss the thing I started doing some research. It seemed my best bet was to braze repair the crack, but with alot of pre-heat and slow cool to prevent cracking. Brazing seemed to be the best choice, as others at Weldtalk had mentioned since it's properties most closely match those of the base material along with being least likely to cause cracking, of all the joining processes. I had a choice to either fully grind the crack out and fill it back in, or try to draw brass into the crack using a capilary action and try to fill it that way. Personally, I thought the chances of fully grinding the crack out and filling it back in seemed like too much of a gamble, so I went the "fill the crack" route.
I practiced the technique with a lap joint on 1/4 steel, and it worked pretty well.
For the preheat and slow cool I decided to use my charcoal bbq. So I lit it up and placed the body on the rack, waited a good 45 min until well done (haha). Then, with the body still on the grill, I heated the cracked area until red and tried to get the brass to draw into the crack. It was NOT easy getting good positioning on the workpeice, and I had to reposition several times to get the brass to flow where I wanted. It honestly took a good 30 minutes and manipulating and re-working the peice. I do feel pretty good with the repair. At one point I was able to see brass drip from the crack at its tip, deep in the body, leading me to beleive brass made its way through most of the crack.
Once done, I recovered the body and let it sit another 2 hours until it was cooled down quite a bit, probably aroudn 200 degrees. Here is how it looked:
Pretty ugly, but I haven't brazed anything in years. I went forth and started removing the excess brass using a flapper wheel, and to my suprise, got this:
The brass looks like it did exactly what I intended it to do ,flow into and fill the crack. I also feel pretty good the brass made it's way to most of the crack, taking a close inspection of the inside. I seriously doubt I completly filled it the whole way, and I am sure there are still crack tips in the body, but I'm figuring as long as I don't beat the living snot out of it, it'll hold together. Anyways, I stuck it back in the blast cabinet and hit the fresh spots, then hit it with a quick coat of rattle can blue I had around.
All in all, it ain't perfect, but I feel pretty good it'll hold up as long as I don't get too rough with it. Now just need to finish up with the rest and get it mounted. Thought I'd just share if anyone else has a similar issue that wants to try a repair.
Even got the original nameplate to clean up a bit. I'll reattach it when I get a few rivits at the HW store.
