Cracked cast iron repair

[onetreeforge]

was trying to do something stupid in my lathe and it went bang as it jamed and it cracked the head stock bearing clamp, I am not even going to bother looking for a new one is it is a 1937 lathe.

 

 

Should I have a go at brazing it? or some other kind of rod I should use? was also thinking about making a metal strap to go over the top

[Larry H]

thats not bad, clamp it to close the crack ( so it isn't loose on the shaft when you're done ) grind a "V" heat it up even and weld it with a 3/32 ni 99 rod it'll be good as new.....only messier 

[pkrankow]

Might be worth looking, lots of tools were produced in that time frame that became surplus. You might get lucky.

Phil

[jmccustomknives]

If you are any good a brazing and that piece isn't put under a lot of stress I'd braze it.  If you decide to weld it use a nickle 99 rod like Larry said.  Welding cast is tricky, and the lower the quality of cast the trickier it gets.  Preheat, pein it and a very slow cool down to relieve stress.   Then you'll have to re-machine because the part will destort when you weld it.

[onetreeforge]

Cool thank you. the peace is cracked right off

 

I don't have an arc welder only gas and mig, are there any bronze rods I should get?

 

I will brow an arc welder from someone if its going to be better?

[macbruce]

I'd use silicon bronze with a tig but OA with the proper flux will do just fine also.....

[onetreeforge]

I have silicon bronze mig wire but would need straight argon,

 

 

Would it be ok to heat it up in the gas forge and braze it?

[Timothy Miller]

That would work.

[Mark Emig]

Take a nice slow preheat, braze it and post heat it. Brazing (if done correctly) is failry strong. Make sure you "cook" any oil residue out of it.

[ironwolfforgeca]

I would braze it myself instade of welding with cast rod OR get some REALLY good ! cast rod to weld it

 

Braze it with -- WORK harding brass--NOT REG BRASS rod -- I do this offen with cast Iron machine parts 

get some @ the welding supply folks or try a welding shop

 

STEVE'S Welding

[Robert Yates]

looks as it has a bushing in it ? as to weld or HTS 528 Brazing Rod it is the best rod to get .

 

"The strongest brazing rod made for joining cast iron and steel, HTS-528 is thin flowing for close-fit joining and repairs on all cast iron, steel, copper, bronze, nickel, and brass. It also will effectively join dissimilar metals. Welders rate its wetness on ferrous and non-ferrous metals as excellent and while it is very hard, it is still fully machinable.

The perfect rod to use for high-heat applications up to 1400 degrees, such as a cast iron manifold or repairing cracks in blocks, suitable for high-stress areas, including repair of bolt lugs."

 

Sam

[Jeff Seelye]

I have several rules of thumb when brazing or welding.

1. If it takes a lot of torque (low speed), I braze it. If it is high speed (usually low torque), I weld it. In other words, if I was doing a tooth on a bull gear, the brazing takes less stress that a weld would.

2. If it stays the same temperature (relatively) I braze, if goes through cycles of hot and cold, I weld it.

What you are doing, I would braze. If I was doing a manifold on a tractor, I weld. The coefficient of expansion and contraction between CI and bronze during heating and cooling will cause another crack.

3.If it is your grandmother's antique whatever, I usually weld because I can't seem to get paint to stick as well to bronze as it does to a nickel weld.

A high nickel content rod is what you would be looking for, usually you can ask for a CI rod, but they do make machinable and non-machinable rods. Also, Brass is a combination of Copper and Zinc, and Bronze is a combination of Copper and Tin (several different combinations here). Brass is great for casting, bronze is great for brazing.

As far as prep, I try to add steps or texture to a bronze job simply to give the Bronze more surface to adhere to, rather than just grind a "V".

If my groove in the CI is large, I have "buttered" the entire surface with good nickel rod and used 7018 to fill it. The 7018 and nickel work well together and you can save some cash here.

There will always be exceptions to these rules of thumb, but for the most part, they work well.

[onetreeforge]

Thanks for the info, I am off to the welding shop now to get flux and rods, I will let you know how it goes

[onetreeforge]

I ended up v ing the crack out with the windy and cut some steps into it with the angle grinder, heathed the whole thing till the paint burnt off then brazed it, went very well, it looks better in tral life.

[Robert Yates]

Not too bad not clean it up and get back to work ;)

 

Sam

[dirt_devil132000]

learned afew tricks from an old fellor that welded for john deere he always told us to weld cast with an old cast iron piston ring i have had great succes with this method

[onetreeforge]

learned afew tricks from an old fellor that welded for john deere he always told us to weld cast with an old cast iron piston ring i have had great succes with this method

I like that, will rember that one.


I put the lathe together, had to take it apart because I forgot to put the belt on, its working better than it ever did, that part must have been cracked and covered with grease so I didn't see it, I can now adjust the clamp so there is no play, it was wiping round before