Welding cast iron... need help quick

[Don A]

I know that this is one of those topics that has been discussed before, but one that only matters when you need it, so forgive me for being redundant.

I just got my hands on a good blower. It's a Canedy Otto Royal Western Chief. Great condition, except the cast housing has been broken where the housing necks down to the flat bolt hole where it joins the stand. This is cast iron, of coarse, and it has left a 4 inch hole in the housing.

Now about fixing this... I have located the following rods:

Hobart Cast Iron Nickel 55

Hobart Cast Iron Nickel 99

Weld-It Nomacast

Do I have any chance of getting this piece welded back?
Or do I need to consult a professional?
Any other suggestions? ... brazing? JB Weld?

Seriously, this is a nice one, and it would definitely be worth the trouble.

Let me know.

Thanks,

Don

[Ten Hammers]

I have brazed Otto blower housings as well as other cast stuff. Acetelyne torch. I have used Forney's X-1000 rod as well for repairing broken cheap vises ( Ace Hardware ) with good results. Vises got pre-heat and weld and post heat and buried in a GI can full of oil dry until tomorrow. The blower housings were just allowed to cool in air ( being thin casting ). I'm sure you will have more opinions. Brazing works well on castings but stainless rods and other high nickel rods work work with experience. Acetelyne and cast rods work. TIG works.

[Thomas Dean]

I have FAR better success brazing cast iron than arc welding it. At TEXAS EASTMAN, where I work, all cast iron repairs come to me....can be a pain and a curse sometimes. I repaired a cast block for a track hoe 4 years ago with brass and it is still running. It had thrown a rod through the side hard enough that it broke the mounting ears off the altenator! Had a 3"x5" hole in the side of the block and they could not find the pieces. I cut a piece of 1/4" MS plate leaving a 1/8" gap all around and used a flux coated brass rod. your blower will look better having been brazed than welding as you will have porosity in the weld deposit. (in MOST cases) With brazing there is no need for preheating, by the time you have the part hot enough to take brass the heat has spread fairly evenly. Also, cooling needs to happen slowly, just out of wind should be OK with your blower. If you have some kaowool it would not hurt to cover it with some but is not a HAVE TO. This should be a fairly easy repair for you if you know how to run brass at all. If this was mine I would braze it and not look back. Good luck and let us know how it turns out.

[Rick Barter]

Off the original topic, but can you point me to a good resource to learn brazing (e.g. internet, books, etc.)? I have been thoroughly frustrated by the process so far.

Thanks,

rvb

[Glenn]

Rick, may I suggest Lessons in Metalworking > Blacksmithing > LB0008.0001.103 Reference materials #103

[Valentin]

There is no way u can make a good weld with any cast iron.I have preheated mines ....it cracked close to the weld ....i took it to a professional (The state welding center) it cracked near the weld weldet with tig...mig ..does not stand the stress when the peace is in use ...
You preaheat both of the pieces you make the weld...after that try to make a collar over the weld that will prevent the 2 peaces moving seperately.You can also try using one of those wonder glue made from 2 compound that will stick everything together ...you know something like locktide after you weld it .If you have stress between the peaces it will brake if it just sits quietly it will last.The weld is just 2 keep the peaces in place not to resist 2 much stress(This is just my opinion)

[bruce wilcock]

35 years back i welded a punch and shear ,i got it for scrap price, the frame had snapped at the jaws ,i used the gas cutter with a big tip got a big area red fluxed it with borax and used some piston rings as a filler ,then coverd it ouer with sand to cool ,i still use it ,not so often now as i now have a hydrolic shear

[Rick Barter]

Wow. Thanks, Glenn. I guess I've been away from the forums for too long. :D

[evfreek]

Whether a repair is successful or now depends a lot on the cleanliness and geometry of the piece that you are trying to repair. Also, it depends on the type of cast iron. Malleable iron is pretty easy to weld. This is what is used to make iron pipe fittings. The welds will stick well, but cannot take any bending.

Some cast iron will froth up if you try to arc weld it. This kind requires brazing or maybe the special rod. Oily cast iron which has soaked up contaminants is difficult to weld. I have heard a trick for brazing cast iron with a lot of carbon which involves using copper oxide to oxidize out the carbon, but cannot remember it.

I successfully welded a broken cast iron vise I found out in the street. It was cracked in many places, and I didn't notice until I hammered on a hinge in the jaws. The base cracked in two places, and the vise was wobbly. So, it had to be fixed. I tried brazing it, but it did not work. Then, somebody suggested that I just weld it. I used 6013 at low amps and it worked! First, I veed out the cracks with a grinder to get all the junk out. Then, I buried the vise in gravel/sand so that only the weld areas were showing. Then, I gave it a good preheat with a propane torch, all over. Then welded, avoiding blasting an area and causing excessive penetration. Immediately after welding, I peened HARD with a ball peen hammer. Hard enough so I was afraid of breaking the base. No loss anyway. Chalk it up to education. Finally, after it was all welded up, covered it completely and let it cool overnight. The welds looked terrible, but they held! Several years later, I found a real vise at a garage sale, and sold the welded one for $10. It had served me well for filing, drilling, grinding, bending, everything except hammering. I learned my lesson. The post vise is for hammering.

[Don A]

Thanks to all for the words of advice.

I have a couple leads on guys that know what they're doing when it comes to brazing (I certainly don't). I think that's the route I will eventually go.

In the mean time... I got this blower when I did because I have the opportunity for a public demo this coming Saturday (I'll post pics & details if it goes over well).

My success is contengant on having this blower up and running by the end of the week. So yes, you probably guessed it, she's runnin' on J.B. Weld as we speak. Just pray that this thing will hold together 'til day's end Saturday. After that, when it breaks, I'll fix it.

I appreciate it,

Don

[High Plains Forge]

I have done some cast iron welding for a customer. The only time it hasn't worked was when I tried to repair the leg of an andiron that had been exposed to a lot of fire over its life. Anyway, I just dress up the weld area, preheat it with a torch, then weld it with cast iron rod. Works most of the time.