You will need to be more specific.  Welding is a broad category.  Underwater pipe welding versus ship or pipe welders... the salaries will vary. 

The American Welding Society has a page that cites welding salaries by state/community.  It is a few years old at this point, but it should give you an idea of the range. Broadly, the answer is "about $30 an hour"... and it appears the number of jobs is growing, especially if you are willing to move to follow the work.

Hello Luis:

In addition to Mr. Emmons response I'd like to share with you a link on the various types of welding positions on ZipRecruiter. You could look at the type of job and compare the salary.

https://www.ziprecruiter.com/Salaries/Welder-Salary-Comparison-to-Related-Occupations

Best of Luck!

~ Sheila