Broken Vice - Ideas?

[dopplershift]

Ok, so yesterday I picked up an old vice from a skip.

Turns out its been broken in a couple of places . One not worth repairing (kinda inside the moving jaw, near the screw).

The other place is at the base of the moving jaw. So this means that the moving jaw flops around and can't be tightened properly. I can supply photos if needed, but not till next w/e.

So, any ideas about how to repair the break? I have a cheapie AC stick machine, oxy set, or MIG. My preferred route by far would be the stick welder .

Cos the vice is cast (i presume), would high-nickel rods be the go? (been reading a few other threads). What about the stainless/disimilar rods?

Also, what about pre/post heating or peening the welds? (Oh, and does peening just mean repeatedly hitting the weld with a hammer as it cools? How does this stop cracking?)

Any and all ideas welcome! Thanks!

 

[rtbcomp]

I think I'm right in saying that it may be cast steel rather than cast iron, I would suppose that the choice of rod is determined by the material rather than how it was made?

 

[shenion]

I think Malcolm put my dismal failure repairing my vice in the arc welding library. Used 7018 rods as that was all I had. Weld cracked a few months later. The entire weld was crystallized and looked like sand.

The block inside the vice that the screw went through had come loose and stripped threads. I just welded it back in with the bolt as a key.

I redid it with cast iron rods and have been beating it to death for a year with no problems. I think the rods were Ni/Fe; they did not say (US Forge Cast Iron rods.) Supposed to be good for dissimilar metals too.

Brazing is another option.
Post some pics.

 

[AshLawler]

I've done a repair to the jaw of my fitter's vice with pure nickel arc rods and no pre-heat, and it seems to be OK after a month of abuse.

The gentle peening is pretty important as a stress-reliever for the casting, the nickel stays quite soft for about ten seconds after you lay a bead and you just let the hammer fall on it a few times to spread it out where it might have pinched in a bit.

The idea is to never to let the casting get hot to the touch while you weld, so run one-inch beads and take a lot of tea breaks.

P.S. BOC charged me £70/kg for 2.5mm Ni rods! It was worth it for me because I get emotional about my tools, but if it's a cheapie vice or it needs a lot of welding-up you might be better off with a new one.

 

[R Kraft]

I welded one about 15 years ago with a stick or two of nickel rod.
V ground out the edges of the break, and Pre-heated the whole thing dull red with a weed burner.
Welded up good and no problems with it cracking.
Robert

 

[dopplershift]

Thanks guys,

Shenion - I read your previous thread (the sticky). Very interesting!

One thing from the sticky: would it be worth 'buttering' with a 309 SS rod, before finishing with a Ni rod??? (Snowcat???) I think I can put a nice deep V on the join.

I'll try and remember to get some pics on the weekend and upload them... I've had a thought about reinforcing the weld with ms plate?

Now: To pre-heat, or not to pre-heat. That is the question

It seems that some people strongly favour it (and slow cooling), while others favour the "slow and steady, keep it cool" approach. So whats the deal? Just personal preference?

Ash - Thanks for your advice... I do get a bit emotional about my tools, but since I picked this up from a skip, and its a cheap, old, battered no-name vice, I just wanted to try out a new welding technique/process!

I know it probably wont be economical, but should be fun, and with luck I'll then have myself a "do anything" welding/hammering/grinding/outdoors vice!

 

[shenion]

I think the idea of buttering with SS is so you can finish with mild steel filler. The M/S will handle cooling stress betterand teh SS will prevent the carbon from diluting into the M/S..

As to pre-heat. My book on welding metals says do one of 2 things:

1 - preheat to somehing like 500F * - cool real slow
2 - no preheat - keep heat to a minimum. Do short burst, wait until cool enough to touch before doing another area.

* temp depends on the type of iron have seen up to 1200F.

I guess the idea is to allow everything to expand/contract slowly. Or put as little of heat in as possible to prevent expansion.

Then there is peening. Supposed to relieve stress. Mine would have been impossible as the weld was inside a 2x3" box. Allows micro-fractures instead of one crack growing and taking up all the stress.

Ni/Fe rods are expensive. I was at my hardware store and found a pack for $6. Sounds inexpensive but that was for 3 rods

Check ebay, I see sellers break up boxes of Ni/Fe rods and sell them a few at a time. Good idea as most users would only need a few.

If I did not find the cast rods, I would have used SS MIG. I tried that on my band saw. It worked well as far as welding, but ruined 2 drill bits trying to re-drill the hole. It well get hard and will work harden easy (not really machinable.)

There are 2 Ni/Fe rods. Something like 65/35 and 95/5. One is machinable, the other is not.

Since there is not much real cast iron anymore; it is more of a cast steel alloy. So, you can probably get away with more. I would not want to touch a pre-war piece of machinery Well, maybe with brazing rods.

 

[Mith]

In the past I have used a blowtorch to heat the item, weld with nickel rods, and then use the blowtorch to let it cool over a period of an hour or so.
We have also used a TIG and used a nickel rod with the flux broken off for small parts too.

I know of cylinder heads and block welded with a similar method too.
Preheat and postheat seem to be the key.

 

[Drains]

The best reason for buttering a job like this is to save money! Ni/fe rods cost more than 309's.

Scott - stainless is very machinable, but also very work-hardenable. Once you've done the latter, the former is almost impossible. The answer is in slow speed cutting, keeping the job cool, and never letting the drill rub. If it rubs or the job overheats, the stainless forms a layer of flat platelets on its surface which are very difficult to break through.

 

[dopplershift]

Ok, so I got some photos finally.

The break is in a slightly different spot to what I thought. Anyway, here we go:





Hopefully they uploaded ok?

And hopefully you can all see the break/crack?

In the 2nd and 3rd photos you can see theres a bit missing... I was thinking of using the corner part of a short piece of heavy MS angle in there.

Any further ideas? Otherwise I think I'll just try finding some Ni/Fe rods and using them.

Shenion - any idea which of the two types is machinable, and which isnt?

 

[Tino]

First thing to do is a little grinding to see what colour sparks you get (very dull red = cast iron , sparkly yellow = cast steel) .I think I would go for nickel on iron and s/s or a dissimilar on steel.

 

[zzr1200]

Considering the size of that vice and the cost of the rods (unless obtained free) and I know this defeats the question, but I'd be looking at a boot fair/garage sale for a replacement or possibly new.

PS: Opps, just re-read your first post, the vice came out of a skip, good luck...

 

[Weldingartisan]

That vice definately needs to go back in the skip!
I thought the principal of buttering was to use the nickel rods first to bond with the cast then a cheaper filler?
I did bronze weld a heavy 'Record' engineers vice years ago, but it was a good quality cast iron - lasted for years. W/A

 

[dopplershift]

Hahaha! Thanks for all the concern over my hip-pocket, but I knew reparing this was never going to be a cost effective option

I really just want to try out the rods and the process Anyway, if I can get the rods individually or in a really small packet it should be ok. Im guessing 3-5rods should do it? Hopefully that will be <$20.

If I get a working vice from it, then thats a bonus! I'm quite keen to have a cr*ppy vice that I can do anything to.... I feel terrible when I'm beating the cr*p out of something in one of my dad's 40+ year old vices!

Thanks for the tip Tino! Really good to learn this type of thing! I'll check up on that...