Vise Repair

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I have an old Prentiss No. 21 vise with 5" jaws, including a back jaw that swivels to hold irregularly shaped pieces of work.The prior owner broke the swivel jaw and repaired it.  He bolted the back jaw down from the top and strapped steel accross the front face of the main vise body.I'd like to fix it, though it was "usable" as is.  I've just started tearing it down.  It's going to be tricky to get everything to line up perfectly, but should be a fun challenge.Would you be comfortable using 7018 stick?  I currently don't have an mig welder, though I am looking for one and hope to learn.I need to repair the back (swivel) jaw which is broken in half (upside down in picture).   Then, I need to replace the semi-circle 'ledge' which held the jaw down and allowed it to pivot.   At this point I'm thinking I'll cut off that whole bashed up casting, and weld on a plate cut to semi-circle.What say you - doable by a rookie if he takes his time? Attached Images
Reply:Heres an image I found via Google that shows how the assembly is supposed to look. http://i984.photobucket.com/albums/a...tissNo21-3.jpg
Reply:7018 would not be my 1st choice for this. I'd probably lean towards brazing for the repair myself. 2nd choice would most likely be tig and a high nickle filler like Ni55.If anyone here would know how to repair something cast like this it's most likely Castweld. Hopefully he'll chime in with how he'd do it..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:if you have no other choice but to stick weld it, preheat the whole unit, weld it and bury in DRY sand for a day to get a very slow cool down...try to get a cast iron rod if you can..Of all the things I lost I miss my mind the most...I know just enough about everything to be dangerous......You cant cure stupid..only kill it...
Reply:I think the sand should be hot or worm also shouldn't it?  John Sent from my XT1254 using Tapatalk
Reply:I think JB Weld will work better than 7018.DanI hope that when i'm dead and gone, people will remember me and think; "Boy, that guy sure owed me a lot of money!"
Reply:Preheat the whole thing, no matter how you weld it.  A propane bbq works great for this.I would braze it, as for strength brazing is a similar tensile strength to that of cast iron.Back to the bbq and reduce the heat verrrrrrrrry slowwwwwwwly.  Else, bury it in dry sand.Good luck, the pic looks like a really nice vise to own."The reason we are here is that we are not all there"SA 200Idealarc TM 300 300MM 200MM 25130a SpoolgunPrecision Tig 375Invertec V350 ProSC-32 CS 12 Wire FeederOxweld/Purox O/AArcAirHypertherm Powermax 85LN25
Reply:Do a grind test to see if it's cast iron or cast steel. If cast iron then I would do it with UTP 85FN rod. They are expensive, about $85 a pound, but the repair will be as good as possible.
Reply:Has anyone here ever used vermiculite for slow cooling? For years, I welded the journals on press feed rolls. The material is 52-100. It's the same stuff that ball bearings are made of. It doesn't like to be welded. The rolls were preheated to 350*, tigged with 308L wire, then the rolls were put into a large metal box filled with vermiculite.Vermiculite is very light and fluffy stuff that has many insulating uses, mostly in agriculture, etc. It kept the rolls warm for many hours.Rich
Reply:Yes, vermiculite is good. I've never used sand, it's too dense and sucks a lot of the heat out of the metal. Doubly so if it is not completely dry. Perlite, Kaowool,and even fiberglass are better.Putting the welded casting into a charcoal grill and letting the charcoal die out naturally is another good method. I have an old gas stove in my shop. I turn it up to 450 to preheat, leave it on while welding, put it back in the oven when finished, and cool slowly.JohnA few weldersA lot of hammersA whole lot of C-clamps
Reply:Originally Posted by DSWI'd probably lean towards brazing for the repair myself.
Reply:the best would be if the wife is out for the day stick it in the oven and lower the temp down over a 10 + hour period...Of all the things I lost I miss my mind the most...I know just enough about everything to be dangerous......You cant cure stupid..only kill it...
Reply:Not sure about that. You might want to preheat it to way higher temperature than a kitchen oven can reach, and the cooldown should begin at such a high temperature too then.
Reply:Originally Posted by DSWI'd probably lean towards brazing for the repair myself.