is welding up cracks in the side of a piston a bad idea? A guy i work with did this to one of his, just wondering if it would have any negatives...
and could you do this to other bits aswell?
Using a tig to do it mind you.

yes... bad idea.
buy new ones, if you cant afford new ones.... wait until you can!!

You should weld your body part sheet metal, and thats probably about it, unless you are a machine shop doing welded counterweights or something.
At 300 a set of barrels and pistons why weld them????

these were for a ford... and its an experiment, just wonderin if anyone else knows of this being done, and with sucess or not...

hell yeah if your a good as welding as me and going to sell the car soon (to some poor sap) hehehe then
JUST DO IT

Where abouts on the piston is the weld ??? skirt or top ??? inside the crown

Whats the weld for to fix a crack or add weight or boost compression ??

You can weld pistons, need right rods, heat treatment, needs to be remachined, will be difficult to get expansion rates the same.

Far far cheaper to buy a new one.

I have seen it done on a broken skirt on an old stationary engine that the pistons are no availabe and weird shape to remake. Was for a resto so was necessary.

For a ford you would be wasting time/$$$