I just bought a 137 lb 9-600 vintage wilton vise for $120.00. It is seized. The size makes it very difficult to work with. Any suggestions in terms of how to un-seize it? Perhaps it's value?
Depending upon the condition (after you get it freed up) anywhere from $300-500 is pretty common if it doesn't have a swivel base. With a swivel base add another $50-100.
Remove the front collar and then unscrew the spindle completely. Take a dowel, slide it through the nut, and knock out the dust cover from the back of the vise. Remove the pins holding the nut in place. Then remove the nut and tail cap assembly. That will give you easy access to the inside of vise. Point it nose down and put a bunch of penetrating fluid in it and let it sit for a couple of days.
After it's soaked for a few days, secure it to a bench, or something else that won't move and then use a block of wood and a hammer to hit the back of the slide to see if it will free up. If not, mount it vertically again, soak it in penetrating fluid longer, and try the block of wood/hammer technique again. If you have a piece of flat stock steel that will fill the hole you could use that on the back of the slide as well....you just want to distribute the force around the entire back of the slide and protect it from the actual impact.
People run into problems removing the pins because they try to drive one inwards, hoping it will push the one on the other side outwards. Frequently they don't line up and you wind up with a pin half in, half out, and no easy way to remove it. This method is easy, quick and essentially foolproof:
Let us know how it works out!