Not technically a welding question but it sort of is. I have a skillet with a pretty large crack starting from the rim and going about four inches into the pan. I unfortunately do not have welding equipment, but have equipment for brazing. I know it can be brazed but my question is should it?  I would rather not pay to have someone repair it via welding if I can do it myself with brazing.  

To properly repair it would cost more than the pan is worth. Does it have sentimental value? I have done cast iron repairs and it is not simply running a bead, it is a process, and even then it is not guaranteed to work as there are many variables.

Nah no sentimental value. I found it lying on the side of the road and can always use practice with brazing. So if it is too much of a hassle I will just toss it.   I just went through all the trouble of cleaning the rust off and then noticed the crack after I had seasoned it. 

Im curious if has a reddish color after seasoning. If it does that would indicate someone  put it in a fire and will never season correctly.  So then its a piece do practice brazing on. Just remember to preheat it prior to brazing. 

Didn't realize that was a thing. No reddish colour. It was so rusty I basically had to scour it to silver. It has more a seasoning you would find on a steel pan than a cast iron one. Won't be quite right but it will still work. I have used ones like that before at a camp and they work just fine. Aside from the crack through the middle. 

Sell it for scrap. Buy steel.

Braze away Rene

If you do not drill a hole to terminate the crack first, don't be surprised when the crack grows during the pre-heat. Vee out the crack area with a grinder, and use plenty of flux. Wrap it in fiberglass when done to let it slow cool.

Alternately, it can be stick welded with 99% nickel rod. Our church has been using a cast iron pot repaired this way for 40+ years of fish frys and spaghetti suppers. (And yes you can wash seasoned cast iron with Dawn so that the noodles don't taste like fish!)

I prefer some of the newer cast iron rods over the old E-99. But they are  a bit more expensive.

Some rods use preheat, some don't  - read the instruction sheet. Weld short beads, peen the weld as it cools to spread it width wise, cool very slowly. I usually gave it a good post heat and covered it in a drum of gray wood ashes.