Author Topic: FPU salvage attempt  (Read 432 times)

jpigg55

FPU salvage attempt
« on: October 09, 2019, 07:57:51 PM »
Some of you may remember this vise from the "Previous Site" which shall not be named.
For those that don't, I found this half buried in one of the sheds on my farm.
The piece broken off the front of the dovetail at the gib screw hole I was never able to find.
Due to a recent project, I now have a piece of cast iron big enough to use for a repair attempt.
My plan is to machine out the broken area and weld in a replacement piece followed by milling the dovetail back in, then drilling and tapping a new gib screw hole.

Here's the question I have. I'm wondering if I would be ahead to drill a hole through the replacement piece into the metal of the vise and inserting a hardened pin or two to add strength to the weld repair ?
SB 9A, Clausing 8520, Sanford MG 612

woodchucker

Re: FPU salvage attempt
« Reply #1 on: October 10, 2019, 02:02:01 PM »
I can't answer that, but I would say, before you start, soak that in a cleaner like purple cleaner. Then rinse, then put it in evapo rust before working on it.
Get it all cleaned up.


I believe a pin or bolt would be an extra support to the weld.  A vise takes a heavy load, so I don't think a braze alone would be enough. but again thats an opinion that has no real knowledge, just a gut feeling.
Jeff
Clausing 8520   SB Model 9a - power hacksaw, Milwaukee band saw in a table.  Delta Rockwell Surface Grinder (not online yet .. being rebuilt where am I going to stick this)
For pics: https://imgur.com/user/woodchucker/posts

PJB

Re: FPU salvage attempt
« Reply #2 on: October 10, 2019, 05:53:41 PM »
Yes pinning will help somewhat but if joint is stressed in tension the trick is to add screws in that direction.   welding ci is really brazing never strong and mostly cosmetic.  Nickel rod and pre heat well. 
"I wants what you gots!"

jpigg55

Re: FPU salvage attempt
« Reply #3 on: October 10, 2019, 05:54:02 PM »
Yeah, 25+ years laying mostly buried in the dirt didn't do it any favors. Just lucky it was in a shed instead of out in the rain and weather.
A good cleaning is definitely in order, but I was thinking of just giving it a good power wash for now and do the complete cleaning and painting after all the welding and machining was done.

The repair will be done with cast iron welding, not brazing. My neighbor is going to weld it for me, he's a retired welder from Caterpillar and did a lot of side work over the years and still does custom welding for people since retiring. He has a lot of experience welding cast iron and even welded a cracked tractor casing for my father years ago.

Speaking of brazing cast, take a look at the second picture. Someone did a braze repair of the movable jaw at some point.
Hopefully, I can see what it looks like after a good wash. Might ask him if it would be worth grinding out the brazing and do a proper weld.
SB 9A, Clausing 8520, Sanford MG 612

PJB

Re: FPU salvage attempt
« Reply #4 on: October 10, 2019, 06:00:57 PM »
I would pre heat the crap out of it and keep it hot after welding then slow cool.  Easy to say right!?  Lol
"I wants what you gots!"

jpigg55

Re: FPU salvage attempt
« Reply #5 on: November 14, 2019, 05:00:42 PM »
Franken-vice, as I've dubbed it, is a bit closer to being useable again, I hope.
I milled out the broken area, cut a piece of CI to fit, drilled & tapped it to hold the replacement piece in place, cut some weld reliefs, and got it welded up.
All that should be left to do is clean up the flat, re-cut the dovetail, drill & tap for the missing gib screw, and put it back together to see how it holds up.

Cutting the dovetail has me a little concerned as I've never cut one before. Nothing like a trial by fire for a first attempt. Mess it up and I might as well scrap the whole thing.
Any advice before I give it a go ?

Here's a few pic's of my progress so far.
SB 9A, Clausing 8520, Sanford MG 612

woodchucker

Re: FPU salvage attempt
« Reply #6 on: November 14, 2019, 06:02:42 PM »
dovetails...
Go slow, measure frequently when close to size.


it's not that hard, but I'm not an expert, but the ones I have done have worked out well.  My first DT was cut too large, so that's why I say measure frequently. After that, they improved.
Jeff
Clausing 8520   SB Model 9a - power hacksaw, Milwaukee band saw in a table.  Delta Rockwell Surface Grinder (not online yet .. being rebuilt where am I going to stick this)
For pics: https://imgur.com/user/woodchucker/posts

jpigg55

Re: FPU salvage attempt
« Reply #7 on: November 14, 2019, 09:31:36 PM »
Thanks, the biggest concern I have is cutting through the weld beads.
I was planning on taking very light cuts and going slow.
Having the good part of the dovetail will help, I think, as the cutter would start taking metal off if I overshoot.
It also helps that the side I have to cut is the side the Gib sets on. Should take up for any minor imperfections to a degree.
SB 9A, Clausing 8520, Sanford MG 612