Donal Harris Posted March 11, 2021 Share Posted March 11, 2021 How would you flatten convex shaped vise jaw faces? Sort of like dentists, carbon paper between the jaws, close the jaws to blacken the high spots, file or grind away the black spots and repeat until flat? Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted March 11, 2021 Share Posted March 11, 2021 One thing to remember is that for Post Vises; the arm travels in an arc and the jaws won't be parallel when completely closed but will be parallel at some point as they open. For unevenness on the jaw face. I would file to contact all over and then use your method to get an exact fit if that was needed. Jaws also get twisted if they are abusively tightened with stock in only one side. Having a set of spacers for the other side is a good idea. I use a set made from the common stock sizes I use, Slit down the axis with the tabs created bent out to a T and punched with the size for students who can't tell the difference between 5/8" and 1/2" by eye. Others use a stack of "shims" with a hole drilled in one corner for a ring so they can choose the size they need and flip the others out of the way. Quote Link to comment Share on other sites More sharing options...
Donal Harris Posted March 12, 2021 Author Share Posted March 12, 2021 I may take a picture tomorrow. This is obviously an exaggeration of what my vise is like, but picture a vice with both faces made of a billiard ball. There is no contact along the faces. There is just a very small area in contact with your work piece. Quote Link to comment Share on other sites More sharing options...
anvil Posted March 13, 2021 Share Posted March 13, 2021 Is it a post vice? Quote Link to comment Share on other sites More sharing options...
Donal Harris Posted March 13, 2021 Author Share Posted March 13, 2021 Yes. It is a post vise. I put some white paper to make it easier to see the gap. Quote Link to comment Share on other sites More sharing options...
Irondragon Forge ClayWorks Posted March 13, 2021 Share Posted March 13, 2021 It looks like the moveable jaw has been sprung some, usually because of clamping stock in the outer edges very tight. I would use a straight edge steel ruler and an angle grinder to take down the center high spot. Others may have better option though. Quote Link to comment Share on other sites More sharing options...
anvil Posted March 14, 2021 Share Posted March 14, 2021 What's the brightwork on the top jaw? I always hate removing material, but I think Iron dragon has the answer. Quote Link to comment Share on other sites More sharing options...
Frosty Posted March 14, 2021 Share Posted March 14, 2021 Do you have a couple BIG C clamps? You could put a spacer in the center of the jaws, say 1/2" thick and put a clamp on the outside ends and put some hard squeezing on it, perhaps a few hammer blows while clamped will do it. Wrought is malleable and might correct without grinding. No guarantees though, of course. I'd hesitate to put heat on it while clamped but maybe. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted March 14, 2021 Share Posted March 14, 2021 I'd go with the grinder and care! Some vices have a steeled face and so grinding would affect that. Quote Link to comment Share on other sites More sharing options...
Irondragon Forge ClayWorks Posted March 14, 2021 Share Posted March 14, 2021 Another albeit harder way would be to remove the moveable leg, put it in the coal forge and bring it up to yellow heat and hammer it straight on the anvil, provided it doesn't have a steel face. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted March 14, 2021 Share Posted March 14, 2021 Should work with a steel face too; I don't think they were heat treated as that makes for a "slick" vice face; they just wanted the greater wear resistance. Quote Link to comment Share on other sites More sharing options...
Irondragon Forge ClayWorks Posted March 14, 2021 Share Posted March 14, 2021 I should have added to put the face on the anvil and hammer the ends down flat. Quote Link to comment Share on other sites More sharing options...
anvil Posted March 15, 2021 Share Posted March 15, 2021 Forging it is an excellent idea. However I would forge the high spot into the vice and use a light hammer. Start in the middle and work to the outsides. Looks like the other jaw has the same problem. Lol, now you are prolly really confused as the which way to go. Quote Link to comment Share on other sites More sharing options...
Donal Harris Posted March 17, 2021 Author Share Posted March 17, 2021 The bright line is from someone welding the face back on at some point in the past. The faces on this one are steel. Vises often take a lot of abuse. My guess is someone missed and hit the jaw and popped the steel off. I am not sure how it was welded. The weld does not rust at all. I am going down to pick up an old homemade disc grinder from my Dad today. I think I will take the vise down and ask him to help me grind down the dome on each face. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted March 17, 2021 Share Posted March 17, 2021 Probably nickel weld. I wonder if the welder knew it wasn't cast iron like most machinist vises... Quote Link to comment Share on other sites More sharing options...
anvil Posted March 18, 2021 Share Posted March 18, 2021 It looks like nickel to me too. That's why I asked above. So I would not forge it. You would lose the repair. That leaves using a grinder. Quote Link to comment Share on other sites More sharing options...
Donal Harris Posted March 18, 2021 Author Share Posted March 18, 2021 We used a grinder. Tomorrow I will reassemble it to see how well we did. Probably wire cup it to remove the rust again, but this time protect it with BLO, followed by more BLO periodically. I should paint it, but just really prefer to see it and feel it and not the paint. Would a waxed canvas cover help? Quote Link to comment Share on other sites More sharing options...
Donal Harris Posted March 19, 2021 Author Share Posted March 19, 2021 I am not sure I made it any better. I took a shade too much at the top and now instead of convex it is rippled. It was maddening. Take a little here and now it is low here. Fix that peak and it just moved somewhere else. If we ever get to begin having local meetings again, I may ask if anyone knows of a machinist who is also a blacksmith or at least knows about blacksmithing tools. Speaking of blacksmithing tools, more than one of mine has the initials of a prior owner punched into it. My vise was owned by C.P.M. I assume that is the initials of the blacksmith, farmer, or rancher who owned it. (Being a nerd CPM meant something entirely different than someone’s initials when I first saw them.) Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted March 19, 2021 Share Posted March 19, 2021 is the face of the jaws soft enough to be dressed with a good file? If so you could true them up without much effort using chalk to mark the places needing filing and when close switching to draw filing. Quote Link to comment Share on other sites More sharing options...
Donal Harris Posted March 20, 2021 Author Share Posted March 20, 2021 I think one side likely will be and it is not the side I would have expected to be the hardest to grind. The welded side seemed to be harder. I will run a file over the jaws tomorrow to check if they are too hard to file. Thanks. Quote Link to comment Share on other sites More sharing options...
anvil Posted March 20, 2021 Share Posted March 20, 2021 If you are not good with a file, levelling two separate faces can be a challenge. When the jaws are closed, scribe a line on each jaw parallel with each other for a guide will help. Another way is to do a marriage cut with a hack saw. Tighten the jaws just snug. Then scribe a line as a guide for your hacksaw to follow on one side. When you have sawn in enough put a wedge in where you started your cut. Don't loosen the jaws! As you approach the other end, you will need another set of wedges to keep the jaws parallel, then finish your cut. When you are done, your jaws will tighten nice and both sides will match. As wide as the gap is in the middle, you might need to put two blades in your hacksaw, or saw it twice. It's a little slow,. But hey, it's precise. Quote Link to comment Share on other sites More sharing options...
Donal Harris Posted March 20, 2021 Author Share Posted March 20, 2021 It will file, but only barely. And I am terribad at filing. What little steel I removed this morning made it worse. I think I will wait till we have meetings again and attend a SW Region meeting. It is often at our president’s shop. He is pretty skilled and may know a machinist who can mill the faces. Or text Byron Doner, one of our directors and former longtime President, and ask him who I might pay to mill them. He would know someone. In the meantime I will just use it as is and maybe cut some covers from scrap copper pipe. I will need them eventually sometime anyway. As for taking a hacksaw to it, I am sure that would work, but jeez! Quote Link to comment Share on other sites More sharing options...
anvil Posted March 20, 2021 Share Posted March 20, 2021 Lol, pretty labor intense. However another solution is a set of jaw protectors. I think that's what they are called. I have some made from copper to protect my work from scratches and some made from mild steel. I've made them from 3/16" and 1/4". The mild steel ones will solve your problem. Quote Link to comment Share on other sites More sharing options...
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