Head Material
Perfacar's way is a good way to weld cast iron if you don't have the right oven for heating and cooling the cast gradually. If you weld a little bit at a time like he says the chance of cracking is vey minimal because of it keeps the heat low. If you are going to weld a big area in one shot then the whole item will have to be heated evenly and cooled gradually which if done wrong will turn it into a big piece of junk. Some peoples idea of heating a cylinder head it to take rose bud torch, heat the area to be welded, then weld it. This is not what the experts mean by heating the item to be welded.