Set up time - Time used to gather clamps, rods, leads, review drawing & general set up a work area. This is anywhere from 1/2h to 2h on very large jobs. This is applied to the whole job regardless of number of pieces to weld.
Piece Time - Time used per job from start to start. In your case it's one piece. I break this down as follows:
Handling time - How long does it take to locate and get one item (or assembly) into position before working on it? Keep in mind that a part may need multiple operations and will be handled multiple times. Small parts could be 1 minute. Large crane or forklift rigged parts much more.
Working time - How long does it take to work on each part? Each operation needs to be estimated based on standard times.
1 - Prep time - How long does it take to prepare the part for fitting? Burning bevels, drilling of burning holes & grinding to fit all is included.
2 - Fitting time - How long would it take to hold and tack this part in the correct location.
3 - Welding time - How long does it take to lay down 1 foot of weld including rod changes? Use the total length x passes divided by your time/foot + time wrapping the ends of the weld to get this figure.
4 - Clean up - How long does it take to clean up the welded area?
Add about 15% to your total piece time to get your part time. Add the set up time then apply your shop of field rate. Add a profit percentage.
Walter A.