Brazing Help!

[Covforge]

Irnsrgn is right about the flame. To save on heating he has a good Idea with charcoal or wood. Get a good hot clean fire and let it soak up the heat and it shouldn't take so much from the torch. then stick it back in the fire to cool slowly. It would be the same as putting it in the oven.
Travis

[11echo]

I understand about pre-heating, but there are two issues with that! One this thing is cast iron about 4'-6" tall with a 18"x 24" base ...i.e. weights a ton! So I'm limited to "freely" moving it around (especially hot!) And Two where I live building a fire outside is fronded upon by the "Air Care Board" ...HOWEVER I have come up with an idea, I have a propane shop heater, I could fire-up and park next to it, that should get it pretty hot!!?

[R Funk]

I don't want to be to repetative (sp) but I would again ask the question why do want to repair the crack? Are they in a critcal location?

If they are in critcal location stiching and pinning could be the preferred repair. (there was a post and a link on stiching and pinning on IFI a month or so ago)

How long have the cracks exisited? Where they loaded with grease and years of dirt?

Are you concerned about structural strength? Cracked castings in non crtical locations have existed in in some machines for years with no adverse affects

If your concern is asthetic Bondo(tm) will do wonders

Just some encourage to reconsider and not make some of the mistakes I made.

[irnsrgn]

reminds me of a local farmer, one of them know it all types, if you don't believe him just ask him. He brought half of the variable speed drive pulley in that had a crack and insisted I gob it up with some nickel rod. I did what was the critical part to him, and left some of the crack cause I knew what would happen. He was very frustrated with me, so he purchased some of the few nickel rods I had and went next door to the impl dealer and borrowed their welder, and proceeded to daub it up with nickel. He never came back, but one of the mechanics told me what happened, just as I had forseen, Bang and he had two pieces. It broke right thru the middle and he had to wait 2 weeks for a new $300+ replacement part. To this day he still won't speak to me when we happen to meet.

LOL

There is a long Crack in the Anvil of my Depew Helve hammer caused from shrinkage when the casting cooled. No one has ever attempted to fix it over its life span and I have no intention of every trying either, It doesn't hurt anything at all. Why put the same stress back into it that caused it to crack in the first place. I learned a lot from the old timers I was around as a kid and learned a lot more from my own experiences over the time I was a shopman.

The important thing is, are the cracks getting worse with use or just lounging around.

[Hillbillysmith]

A neutral flame would be best, but a carbourizing flame is WAY better than an oxidizing flame.