How To Weld Cast Iron... Like A Cheapskate

Lanse

Well-known Member
Hey guys!!

So, things are going alright for me now... Tomorrow (Monday) is my first day of School at Hobart, looking forward to it :)

Anyways, this is one of my next projects:

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Its a broken Chas-Parker vise from a local steel yard. The place is probably three acres, and theres a 12x12 shed of good, clean,new metal. The rest is full of... well... junk. They sell steel by the foot, and although it is expensive, buying it from them saves me the 50ish mile trip to the "other" steel yard. I was there a few weeks back, and found this poor broken vise sitting in a shed(like thing) and brought it home. Figured it would be a fun project if nothing else...

Heres the dilema.. I'm in this thing a whopping $20 (I know, I know, the guy there is a tough negotiator but its got to be worth atleast $10 in scrap lol), and its clearly broken. Its a thick casting, probably an inch in places. Theres no way Im going to spend $100+ on specialty cast electrodes to fill that opening when theres no guarantee it'll even work (even less with me doing the welding), and you can buy a nice Chinese wilton vise thats bigger and probably stronger for $250 anyways. This vise, just isnt worth it.

A buddy of mine grew up welding on a farm, and is of the "screw it, lets do it" mentality. Says he's welded cast with 7018 many times and its almost always held... And I've heard of people using Stainless Steel tig wire, and tigging it. Im told these old vises are quality castings, so they should weld better than some other things, cast wise atleast.

I can understand spending a fortune on Ni rods or something and doing it "right" if its a super rare engine block, or head, or something that lives and livelihoods depend on, but this... isnt. Its like an old beater pickup, sure the "right" fix might cost $1000 but its a $600 truck...

Anyways, I wonder what my best bet here would be.

Im thinking I could grind a nice "V", preheat and 7018 it, then bury it in sand and let it cool slowly. When we learned about 7018 in welding class, our decades old paper thing we were handed mentioned that 7018 could be used for welding cast in some cases, and I've always wanted to try it. Or do the same thing, but replace the 7018 with some 309 stainless tig wire. Its pretty rusty... And Im partial to SMAW, so I think Id rather not go that way...

Look, its not like this is for a customer... Its because... I dont really know why I bought it lol. It'll be fun. If it works, GREAT, if not, the loss of $10 and a few electrodes isnt going to break me.

Who's successfully welded cast with 7018 or stainless wire or the like? I understand cast is always a little bit of a crapshoot, but like I said, Ive never done it.

Ohhh, and another update. I got the new StickWeld wired in, and tried it out for the first time tonight. That thing is SWEET! I'll have a video here soon. Have a nice week, everyone :)
 
For that particular repair, I don't 7018 is the
best method but might be a good experiment if
nothing else. You'd have to do a lot of grinding
an preheat the crap out of it. Before welding,
clean up the grinding with a carbide burr. Do
short welds (1") and peen them with a small ball
pein hammer or dull chipping hammer. You don't
want to beat the death out of them as instead of
relieving stress, it would add stress. Just hit
the hot weld with a heavy tap about 10 times. If
you had an oven to put it in after would be ideal
as you could gradually lower the temp. If it was
something you really wanted to save, I think spray
welding might be the best fix. George MD would
probably have a good idea.
 
in the past, i have used 7018 to weld cast steel, but not cast iton. i would think the 7018 would make the cast iron brittle, maybe pulling the weld away when the vise is tightened up. i have however repaired the same break on about the same size vise by brazing with a bare brass rod and some blue peterson flux. the vise was in use daily when i retired 7 years later. i filled a few scrap boxes while learning what worked and what didn't. good luck and have fun with it.
 
Hey Lanse, looks like it's about time you learned to braze. In a situation like you'v got here a 7018 simply isn't going to work. I can say that because I've tried it before and the result has always been the weld pulling away from the cast, or the casting simply breaking off right beside (within 1/16 inch) of the weld due to the change in chemistry in the cast caused by the weld.

That said when it comes to a good, cheap, and lasting repair for cast you simply can't beat torch brazing. Over the years I've repaired parts of vices, tractor axel housings, flywheel housings, etc, etc, all by torch brazing. I've also watched an old welder/machinist, that was my 'go to guy' for anything welding related til he passed away a couple of yars ago, braze the head off of a pretty good sized old hydraulic press. In that instance parts of the casting were well over an inch thick. What he did, and what I always do myself, is to V the cracked area either halfway through from each side, or all the way through from one side (depending on the part). From there get everything hot and then start brazing. Once your done put the part in a bucket of sand to let it cool slowly, just as you would if you were to weld it. In the end you'll have a repair that should be just as strong as the solid cast part origionally was.

Beyond that, good luck, that's too good of an old vice to just throw away based on an easily repairable break.
 
What I'm looking at when I see your pictures, makes me think that even if you were able to weld that back togather, it would be very weak whenever you use it, and would likely break whenever it is used. Stick is right, however. If you could get ahold of George MD, he would know what you could do to correct it, if possible.
 

Lance,

Anyone that tells you that you can get a
strong weld with any type of arc weld is most
likely full of some kind of compost. One possible
method with arc is to heat to 900 to 1000deg f
and weld with a nickel alloy of your choice ,
typically no one is any better than the next as
they are all in the range 90k tensile and cast
is rarely over 50k.

I think this is your chance to learn to weld
cast with a torch and cast iron rod ( cast iron
in stick form). I have welded vises and one of
them I use every day ,done with cast rod and
torch. Basically for a vise if you want success,
weld it with a torch , if you want it to fail
in use ,arc weld it. I undo a lot of arc weld
damage and redo it with torch.

If you want to chat about it send me a phone
number and I'll call you.

george
 
george md, I for one would be very interested in reading about your technique for welding cast iron with a torch! I can probably count on one hand how many times I've had to repair cast[u:3701dfebb6] iron[/u:3701dfebb6]. Now cast [u:3701dfebb6]steel[/u:3701dfebb6] I've done numerous repairs on pile driving equipment. For years the company would buy a rod by Welco, called Super Missile Weld. Basically just a more expensive 312 stainless steel. Later we just started using 7018. Now this was on cast [u:3701dfebb6]steel[/u:3701dfebb6], not cast[u:3701dfebb6] iron[/u:3701dfebb6].

I think this was posted by member Cast Weld on Welding Web forum. If I remember correctly he repairs cast iron for a living.
I do a lot of cast iron repairs with 100% success so far. Last year, after several months of research, I found information on a couple websites & mostly in an old Lincoln Welding book. The process is called "Cold Welding Cast Iron With MIG". I practiced several weeks on broken cast iron parts & broken/cracked manifolds my bro' gave me to get my technique down pat. It has worked with superb results.

I use MIG, 309/309L .030 wire, 98/2(AR/CO2) @15cfh & generally in the 80A range. You can use any gas with a mix of no more than 5% CO2 (ex:95/5). The 309 wire has a carbon content of .01 & works best. The idea is to keep the temperature cool by running short beads <1" & allowing the joint to cool before continuing. After running the short bead, you can take your glove off & lay your hand on the metal & will feel only warm to the touch. Since your pieces are not large, I would suggest shorter 1/2" beads & allow each weld to cool back to room temp before continuing.


On Tractorbynet forum there is a member there who goes by yomax4, he does a lot of cast iron repair with Spray Powder Torch.
 

1) Machine the broken end of the slide bar back to good metal.

2) Machine a socket in the vise head to fit the slide bar.

3) Fit the two parts together and furnace braze.

4) Tell everyone what ever story you want and stick to it.

Enjoy your class at Hobart.
 
I will have to side with the "braze it" mentality. I
am not sure I would V the pieces but I am very sure
I would sand blast the surfaces to be brazed and get
the closest to clean casting at the joints. The
braze will only be as strong as the metal is clean.
Make sure that you use good flux on the joint and
the adjoining surfaces. This should give you a
strong part when you are done.
 
It looks like your third paragraph contradicts the first paragraph. I know you have much experience and I respect your opinions but please explain.
 
If you use 7018 on that vice you will fix it alright. You will fix it so it can't be fixed. Listen to George Md. He is the cast Guru. As for your first day at Hobart. Now you will begin to find out what you know and don't know about welding.
 
Lanse, I would take it all apart and V it out. Then I would drill in from the handle end and tap the slide and install grade 8 bolts from the handle end.
Then braze or cast rod weld with the torch after heating and then slowly cool in sand. If you could get 3/8 or 1/2 bolts in it, it will be very strong.
You may be able to put 4 bolts.
Richard
 
Boat anchor. Be sure to use a rope that is easy to cut, so you can leave the "anchor" at the bottom of the lake.
 
clean it up , heat up red... the whole thing, put it
on a charcoal fire or something. Weld it with torch
and cast iron rod and cast iron flux. let it cool
in the fire as the fire goes out. Have to v it out
some. I have welded with torch and cast iron rod
many times, takes patience and a lot of heat.
 
good luck, it can be done but ive never had any luck with welding cast iron,but then i really dont have the proper shop set up to do it right either, if you do get it fixed be sure to let us know how you did it
 
I retired froma press repair shop and our welder would braze press beds back together. Some were 10 ft by 5 ft and broke in two peices. After he finished they were capible of being used in a 100 ton press. He would spend a few days veeing it out and pre heat if for 8 to 10 hours , use a big rosebud and 1/2 inch brazing rod and get in the tent he had made and braze, Never did have one break. He claimed brazing was stronger then the base iron
 
You will be throwing good money after bad, maturity is reaching a point where you can determine that. I would keep my money for school.
 

I think projects like this are a GREAT way to learn... I've always said, I learned more in the School of Hard Knocks than I ever did in a classroom... (especially considering how much grad school cost me)...



Howard
 
I'm certainly no expert welder, but I've welded a few cast pieces succesfully, and had a few failures. Some guys who deer hunt here on our place gave me a 4" cheap vice about 20 years ago. A few months ago I was seriously abusing it and broke the back jaw completely off. I figured it was finished. Didn't even bother to vee out the crack - just stuck it back in place and make a couple passes with 308-16 stainless. So far it's held. I use it about every day.

My worst failure was a broken fire extinguisher bracket off of our fire truck. I took it to welding school with me and repaired it using the technique right out of the book. Veed out the crack, built a brick enclosure, heated it red with a couple big rosebuds, welded it with a torch and cast rods, then slowly cooled it in air slaked lime. A beautiful repair. Next class the instructer proudly held it up to show everyone what could be done if we followed the book. I thought I was really something. After class I dropped it in the back floorboard of my car and it fell in half. Never had the heart to tell the instructer about that. . .
 
You could no doubt weld that with a nickle rod such as the Sodel 35... but I can just about promise you that the cost of the rod will exceed the value of that vice by the time you're done.
Honestly, simply for the value of the vice I'd toss it in the scrap bin and be done of it.
If you're just wanting to play with it to say you fixed it... and do it cheap... I think I'd braze it. 10 bucks worth of brazing rod will probably do the trick. I'd bevel it out a fair bit but not all the way through... just so you have enough original surface left to keep it straight... then clamp it and fill the gap.

Rod
 
That joint doesn't have to be real strong. It's mostly in compression when you tighten the vise.

Frankly, if braze is strong enough, then 7018 should be strong enough too, as long as you do the whole preheat thing.
 
Lanse, I welded some cast with 6011 twenty five years ago and it's still holding. It's the casting that comes off the top of the radiator on a 630 deere. The muffler bolts to it. I tried brazing,I tried nickel, both of them ran off like water, probably due to poor surface prep, my fault. So out of desperation I started in with 6011, peening after every pass. No pre-heating. That tractor was used every day as a loader tractor up until ten years ago, then every other day till two years ago, and it hasn't broken yet. But I haven't driven under any more low doors to test it either!!!! Jim
 








Welded a grain platform pitman arm on a John-Deere 95 combine still holding up today. V it out and weld with 6011.
 
The third paragraph is quoted from another source, as stated in the 2nd paragraph. Not as clear as it might have been with quotation marks, but besides being one of the most knowledgeable contributors on this site, Puddles is also one of the most articulate. I wouldn't begrudge him a couple of quotation marks.

Stan
 
I have a good but smaller vise in my one shop that I broke the tab hooked under mounting ring- the part that lets it spin around. I welded the vice down solid to the ring with a bead of nickel rod around the joint and it's been holding up great. I have good luck with nickel rod but it takes some experience. I don't bother trying to weld "real" cast iron with anything but.
 
Look carefully at where it's broke, it's on the 'beam' that carries the front jaw. That being the case as you tighten down on the vice the force of the jaws closing together will create a force that wants to pull that piece apart, not push it together. In other words the resulting force of clamping something puts that area it in a state of tension, not compression. That being the case, that area needs to be one of the stronger spots on the vice to handle that much force being exerted on it. Even so, a properly brazed joint, or a joint torch welded with cast rod like George does, should stand up to the load since either repair, in theory, should be as strong, or stronger than the origional part.
 


Puddles,

I would be delighted to chat with you
about the process and welding in general. I used
chat with T-Bone every now and again , sure
miss him.

Send me an email with a phone # and I'll call,
I'm always here till at least midnite.

george
 
I too have a small vice that I bought broke and need to weld it. I am going to do the oxygen/acetylene weld. When I was in welding school 40 some years ago we used a square (cast) filler rod. Is there only one type of cast rod? I am guessing there is round rod also. Since welding school I have only used Nickel electrode. Since seeing your work I will go back to oxygen/acetylene where possible.
 
These kind of projects are fun to learn on. I'm in the "try it and see" camp.

The brazing is probably the best bet. I still see a fair amount of old braze repairs on cast implement parts. Try and find out exactly what kind of iron it is. If it's white iron I don't think you'll have luck with conventional rods over brazing. If it's malleable or ductile the regular rods may have some success.

I do my own repairs but don't consider myself a "welder", nor do I play one on TV!
 
I have successfully welded broken cast parts the ran for decades (even to my amazement!), but a vice , stressed it tension like this break, is not likely to be a long term success story, but you are young, cheap time, learning experience, I say have at it. If you need another one, I have a really big vice, broken it the same spot, out here in my junk pile, that I decided that replacement was the better route. Seems a shame, but life is what it is.
 
I had a telephone conversation with George last evening. Boy did he ever educate me on cast iron repair! Thank you for the education George! Where I was all wet, I thought you only brazed cast iron with a oxygen acetylene torch. No you actually weld it with cast iron filler rod. George was saying you can even use an old cast iron bath tub for filler, just break off the porcelain.
Here is a picture off of George's website. See the gray square rod? That is the filler rod! Also a can of flux, you do dip the rod in the flux like you would while brazing. Preheat, and a controlled post heat are very important!
Again thank you so very much for the education George! :wink:
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Puddles - where do you get those rods? I don't see them for sale anywhere. The ones we used back in the 70's were about 5/16" round, rough finished, kinda had a texture like an old window sash weight, complete with the mold marks. Not an electrode. I guess I forgot about the flux. Too many years ago. . .
 
FAAAR from a pro welder here - but if it were me - I'd just deep v it all along the outer edge of the crack - preheat the whole thing for good measure - and use the cheapest nickel rod I could find. (tractor supply stuff?)

If that starts getting expensive, I'd finish up with some 7018.
 
We had triangle cast iron rods when I did it in school. I remember you had to be real generous with the flux and dip the hot rod into every few seconds. Molten cast iron is the consistancy of pudding.
 

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