# Vice Repair (Welding) Advice?



## Charley Davidson (Apr 20, 2014)

Benny gave me a vice that has been broken in half & repaired by screwing it back together, I would like to do a better job & paint it up. What rod and amps, process to do a good repair?


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## Don B (Apr 20, 2014)

I'd be the first to admit that what I know about welding you could write on the head of a pin, I've never welded cast but I've had real good success brazing it, it makes a very strong joint on cast, is that an option for you?


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## Charley Davidson (Apr 20, 2014)

Not really as I don't have any oxy or gas for my torch set yet. ($200.00 for acc tank)
So I really want to weld it with my stick welder


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## JimDawson (Apr 20, 2014)

Here is a pretty good write up on welding cast iron.  http://www.lincolnelectric.com/en-us/support/welding-how-to/pages/welding-cast-iron-detail.aspx


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## blaser.306 (Apr 20, 2014)

Use a high nickel rod and enough amperage to get good flow! The trick to welding cast is preperation and babysitting it afterward. "v" out the crack , then pre-heat where you are going to weld. Lay in a root pass and then using a chipping hammer peen the everlovin @#$&% out of it! Follow that up with a couple of fillet welds. When finnished repeat the peening process as outlined before( this helps to releive the stresses caused bu the intense heat  ). After it is all said and done, you are not quite done yet! Post heat the cast and bury it in a can of floor dry or something like it while it is still hot, and allow it to cool slowly. I repaired a 8" Record that a co worker and I managed to break thru the throat one day , attempting what the boss thought to be a good idea! I have been beating on that same vise at home now for about 10 years with no sign of dammage.


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## Rbeckett (Apr 20, 2014)

High nickel rod on high amps and preheat the vise to a dull cherry red before you weld.  Once it is welded and still cherry red bury it in some fresh sand and let it cool overnight in the sand while it is well covered.  That will get the crystals properly arranged and help strengthen the weld enough to pull down as hard as you would like with no fear of breaking it again.  Pm me if you need help with selecting a rod or getting the preheat hot enough.

Bob


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## Charley Davidson (Apr 20, 2014)

Looks like I'm gonna have to wait till I get the acetylene tank to do this project. I'm getting ready to sell off all of my grinding equipment and use some of that money to tool up for things I started out originally to do that I can make money at.

I see a couple different variations in Bob's method and Blaser's method so I need to study up a bit, I know I have heard quite a bit of talk about peening. It may be a month till I get around to it now.


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## Rbeckett (Apr 20, 2014)

Yup V-cut the crack about 1/2 in. deep in the entire crack all the way around on both sides.  Once you have it fitted tightly you can use a burnzomatic Mapp torch to preheat the casting and weld 1 inch long beads then peen it with the pointy end of the slag hammer and repeat till you have built up the metal all the way around flush or even slightly above the surface of the weld position.  Peen it extremely well between each bead and keep the heat on it till you are done weling and peening the completed repair.  Then I always used a bag of white playground sandy and threw the part in with the heat still on the part and covered it up.  That will give you nearly 100% penetration of the weld into the base material and allow the chrystaline structure to normalize without  putting more stress into the vise and causing it to pull in funny directions.  Once it is cooled you can re-mill the faces of the vise and the top to insure it is square to your machine and the table.  Good luck and PM me if you need any help selecting the right rod and heat on your welder. Remember pre-heat and peening will relieve stress buildup and prevent rebreaking after the weld is complete.

Bob


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## ericc (Apr 21, 2014)

If you only have a stick welder, you will still have to get a torch.  I have found that a big propane torch is good enough if you don't have an oxyfuel torch.  But, you will have to, as others suggested, be prepared to bury the piece.  Sand works, but there are better things like soft firebrick or kaowool.  Don't inhale the fibers, but you should be ok as long as you don't get it too hot.  Heat to near or past red, and weld.  Peen immediately after welding hard enough to be afraid that you will break the vice.  If you break it, too bad, it was meant to be broken.  When done, the vice should still be very hot.  500 (blue) may not be hot enough.  Bury with sand, fiberglass, whatever, and let it cool overnight.  I have been successful with 6011, but others have reported that 7018 is better.  Nickel is great, but pricey.


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## Charley Davidson (Apr 21, 2014)

Peening? In/on the weld or just near it? How many strikes? All the way around?


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## Tony Wells (Apr 21, 2014)

You can't really peen it too much, unless you do it long enough for it to cool off. Be thorough, and basically leave no part of the weld bead unpeened.

I have used a gas bbq grill to get a larger casting up to pretty even heat, then a rosebud to keep the weld area a bit warmer. Vermiculite or sand, or at least back on the grill running wide open for an hour, then down a little at a time works for me. It will run thru a bit of propane though, or if you don't have one, just bury it.


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## Ozwelder (May 19, 2014)

G'day Charlie,

I have done a number of cast iron vices and found the quickest and most fool proof  way was to braze weld them.Manganese based brazing rod is best suited.They work has to be  cleaned and veed out.

Be aware that some angle grinder discs throw off some contaminant that is very difficult to deal with as it embeds in the base material and can make brazing or welding a PITA.

If you do have the rods and flux and a means of maintaining post heat, the very best of all the welding processes is with 100% cast iron filler rod.

Use a big welding nozzle say around .10"orifice  diameter with a strictly neutral flame .Acetylene carbon rich flames will render the cooled weld hard enough to ruin grinding wheels. The molten cast iron can be manipulated with the point of the ( neutral ) flame .Molten cast iron the consistency of molasses and as such can be "shoved " around by the flame point to release the embedded gas holes and impurities which will released and float to the top and adsorbed by the flux which floats around the top of the molten weld pool.

The above ensures a very clean welded zone .The cooling down process  must ensure that the whole job cools slowly at a consistent rate. Covering the completed  work in dry sand is a good way to achieve this. It takes at least 24 hours to cool to ambient temperature.The completed weld will be able to be machined with ease.

Hope this helps you

Ozwelder


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## ericc (May 19, 2014)

The advice about preheating and peening is very important and cannot be overemphacized.  In fact, with enough of both, you can weld the vise with almost any rod.  I have sucessfully repaired a cracked vise with 6011 and there is a video by a welder named ChuckE2009 or something like that who uses 7018.  What I did was bury the vise in gravel/sand so that only the V crack was showing.  I then gave it the propane torch.  I used a large BBO tank torch like a weed burner.  When it was nice and hot, almost red, I gave it the stick.  Plenty of peening.  I hit it hard enough and often enough so that I was afraid that I would break it.  When the weld was done, I threw a shovel full of dirt on top and left it until the next day.  It worked fine until I sold it on Craigslist when I got a bigger vise.

Be careful about those high nickel rods.  You can pile a lot of $$$ into that drack, and if it goes ping, you are going to be sad, but not much smarter.  I have seen welds with 10 lbs of expensive rods go ping, and the guy had to air arc it all out.  What a pain.  Most people on the websites are repairing a low value item, and it is not a good idea to put too much $$$ into the crack.


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## Don B (May 19, 2014)

Tony Wells said:


> I have used a gas bbq grill to get a larger casting up to pretty even heat, then a rosebud to keep the weld area a bit warmer.



Funny how a person can have something right under there nose and overlook it, BBQ, what a good idea..!


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## Ozwelder (May 19, 2014)

I have been welding cast iron on and off for 46 years and can claim experience and a good knowledge of what works consistently  and what does not. 
The first two years of my apprenticeship were almost  entirely dedicated to the welding of cast iron. Mainly the cast iron welding repairs were carried out on the pre combustion chambers of CAT 4 cylinder diesel engine cylinder heads. 

The cylinder heads were always tested after welding for cracks, by filling the water jacket with kerosene. The process used was oxy acetylene flame fusion welding process with a modified water cooled gas nozzle. Standard welding torch nozzles in the confines of a red hot PC chambers tend to crack and then backfire.vBelieve me you don't want a backfire from a nozzle in a semi confined space when pushing around a molten cast iron pool that can be an inch in diameter.

The pre and post heating was achieved by a 2” gas burner, meaning that the work was laid out on the ground and a wall of firebricks built around it and a sheet of iron laid across the top and heated until red hot. We had a couple per week over 10 years and I recall only a few in service failures.

The high success rate was due to :
knowing the type of cast iron
knowing the process to use
Using the most suitable welding technique]
Experience of the welding operator.

The following is intended as constructive criticism not an attack on anyone so please take it the right way OK!
Because a person has welded  a cast iron unit  with perhaps  6011 electrodes or indeed 7016 does not mean that such electrodes are suitable for all cast welding jobs. It just means he/she have been very very lucky. Yes! I understand that we are only welding a vice here but it is important to understand what you dealing with otherwise the success of your effort is just down to luck and not consistently repeatable. Circumstances sometimes dictate what process and consumables are available and you have to work by necessity  from there, but when you have a choice your opportunities for success multiply if a procedure is followed that takes all of  the variables into account.

What has not been discussed is the carbon percentage.Steel based  electrodes( 6011 or 7016 only have a carbon content of around .03% wheras cast iron carbon content can range from 2% to 7%. No wonder you have to peen the bejesus out of them. The higher the carbon content of a ferrous based metal the more difficult it becomes to weld.Do the math as I have heard you fellows say.The carbon content is not just tens of times greater , it is in he hundreds.

The other thing cautioned against was with  the nickel based  electrodes.They are great if you get the correct grade of rod suited to the job-ie grade of cast iron and carbon percentage.Some will make your finished hardness so great it can only be ground.Not good at all when you want to drill and tap a hole.

Charlies  vice is more than likely made from grey cast iron if it is of a decent quality manufacture. If its not it may be anything. Its not unknown for a run of small CI products to cast from leftovers from another job. Its just another variable which can turn an apparently "easy" job into a difficult one.

I will come back later and discuss this further  as I am short for time at this moment.

Oz


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## Ozwelder (May 20, 2014)

I am back,
Another  of the welding variables variables to be considered when welding cast iron is the thick and thin sections a casting may have. 

It is critical that during the welding and cooling phases that the unit temperature is consistent across all sections .In other words do not allow sections to heat up and cool down at differing rates. To do otherwise invites a crack across the thin section being the weakest area. Take a cast iron  pulley wheel. The wheel spokes being of the thinnest cross sectional area,are prone to cracking when cooling 

As mentioned first up cast iron is prone to absorbing stuff like oil. Oil consists of hydrocarbons .Remember the carbon, no extra carbon is wanted in cast iron as there is already plenty to go around already.The same goes for,grease, paint and dirt.

If you really must use a grinder disc ,do so and then just knock the ground surface off the prep with a carbide grinder burr. 

*To recap on welding cast iron*

*ID* Type of cast iron- generally from the application of the casting cylinder head ,lathe body , machine vice ,etc
*ID* the carbon percentage -this can be looked up from the cast type on the net
*Perform* an adequate qeld preparation
*Select *the welding process

*Select* a suitable heating and cooling procedure.
Its all I can remember at this point.
Oz


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