Repairing destroyed vise

I'm not talking about the dove tail, but the actual top surface or the movable jaw. Just the top surface.

Basically, I'm asking how to machine cast iron. Hss? Carbide?
 
I worked with epoxy composites for six years with a good deal of time spent studying cure rates.

When an epoxy has hardened to the touch, it has only cured about 10%. A full cure can take years for epoxies that take a day to harden. Epoxies also continue to shrink with curing. Heat will hasten the cure with the cure rate doubling for every 10ºC increase in temperature. A higher temperature will also result in a harder and more heat resistant product. Epoxy also has a property called the glass transition point which is the temperature at which the cured epoxy changes from a rigid to a plastic solid. This temperature increases as the cure becomes more complete

If I were repairing the vise with an epoxy composite, I would fill the recesses generously and allow to cure at room temperature until hard. Then I would slowly increase the temperature until it reached between 110ºC and 130ºC. This process would take place over several days and the epoxy should be close to fully cured.

As to the composite, I would use a slow curing epoxy and mix in iron powder to make a thick paste. Not having the powder, saw dust from cutting iron with my horizontal band saw or filings from filing with a fine tooth file would work.

Fully cured epoxy is fairly immune to most solvents. I would expect good resistance to the chemicals that would be used in machining.
I'm gonna try the heat cure you speak of here. I have a crappy electric skillet we don't use,
15140412522535015792531502829991.jpg
This skillet is junk, so the wife won't care. But this set up will heat the epoxy up slowly. I only have it set to about 120 deg c. And I have the garage heat on to 18 since it's -6 right now. The heat should transfer through the metal block into the vise slowly. I'll leave this set up for a few days? Really shouldn't cause any problems.
What do you think?
 
I purchased a second hand mill back in the end of January. It had a 4in vise which had some small dings, no major drill marks. Biggest issue was the thrust bearing had fallen apart. I ordered a new 4in vise but decided to try and improve the old vise just to see if I could.

Before machining the rails I checked the bottom of the vise by running over a piece of 600 grit wet dry paper on this granite plate. As expected, it was not making consistent contact. I continued running this over the wet dry paper until I was happy with the bottom.

I appreciate this is not the ideal method, but I do not have surface grinder or access to one, so using what I have available.

Vise_bottom_sanded_flatter_7539.jpg

I then mounted back on the table and milled the rails to get them flat and remove some small dings. I do not recall how much I removed, perhaps 30 thou. I used HSS endmill because it was all I had at the time. Multiple passes on each rail so you can see the overlap lines.

I forgot to take "before" pictures.

Vise_rails_after_machining_7538.jpg
 
I'm gonna try the heat cure you speak of here. I have a crappy electric skillet we don't use,
View attachment 250693
This skillet is junk, so the wife won't care. But this set up will heat the epoxy up slowly. I only have it set to about 120 deg c. And I have the garage heat on to 18 since it's -6 right now. The heat should transfer through the metal block into the vise slowly. I'll leave this set up for a few days? Really shouldn't cause any problems.
What do you think?
That should work. Have you got a means of monitoring the temperature? I have a thermocouple for my digital multimeter but I would think something like a candy thermometer would work.
 
I have zero means to monitor the temp. I used to have a laser thermometer but it sucked and I took it apart for its 9v battery clip. Lol.
 
if you were so inclined,
you could make a scraper from an old file and scrape the surfaces to the accuracy you desire
 
Scraping is something I wouldn't mind learning. My lathe is in pretty dire need of scraping.
But it looks pretty tedious, and the good Lord knows how much I detest anything tedious.
 
I would have over-filled all the holes and then clamped a piece of flat stock to it, using waxed paper as a release agent, hoping for a surface which needed very little secondary work.
 
So I’m gonna start machining this vise tomorrow. The epoxy has been on the heat for a few days now and it’s harder than a coffin nail. So I think it’s ready.
I’m gonna machine new jaws, but what should I make them from? I don’t want super soft. But I cannot harden and grind.
 
So I’m gonna start machining this vise tomorrow. The epoxy has been on the heat for a few days now and it’s harder than a coffin nail. So I think it’s ready.
I’m gonna machine new jaws, but what should I make them from? I don’t want super soft. But I cannot harden and grind.
I like mild steel jaws on my mill vise. Seem to grip tighter, are much easier on tooling if you accidentally run in to them them (me, never! so far...), and they can be machined flat and smooth again easily, even in place.
 
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