Farmall Cub

I've used a torch for cutting, but haven't (luckily) needed to heat up parts to loosen them before. Can one of you give me a quick lesson on the right and wrong way to heat up steel and cast iron? Amount of heat, color to look for, how long, etc. I'll practice on my burnt Cub and see how much more I can dismantle for future projects. Thanks, Bob

I first soak things for a couple of days with Kroil or Seafoam. I try not to heat the cast any motre than I have to. Fortunately if I keep the heat concentrated on the steel bolts a dull red, up to a bright red but below melting can be enough. I know that when you weld cast if you let it heat too much you can cause cracks in the area between the hotest and cold metal so I try to not let that happen. I have never had to do more than that. There have been a couple of occassions where that had to be done a couple of times.
Let one more knowlegable than I talk about burning out bolts. I have never done that.

Bill

I would recommend NOT using any kind of penetrant where you expect to use heat later. The reason is that the penetrant can carbonize and actually work against you. O K, I know you can't always know that the penetrant wouldn't do the job and heat would be necessary. Catch 22!

I use propane instead of acetylene, much cheaper around here.

rjmac
I f you are going to burn or heat DO NOT use chemicals.They will be hazardous to your health. Heat nuts to bright red.Bolts heat red and dose with cold water, do not try to turn a red hot bolt with a wrench the head will twist right off. BTDT!