Blue Collar Skills at what price?

Jonathan Potts at the Conversation is linking to a local interview on economic development and notes that the common thread is a lack of skilled labor:

I have to tell you, almost every place I go in this country, particularly where the economy is growing, if you ask business people what is it that would really help them, they say "skills." Machinists. Welders. It's not like there's a Ph. D. shortage, generally speaking. But there is a welder shortage, there's a plumber shortage, there's a machinist shortage....

Speaking as someone who grew up in a high skilled labor family, and have spent the vast majority of my life in cities that have lost their core economic base as either the cotton or steel mills closed, I have to ask two questions. The first is the econ 101 question --- at what cost is their shortage of highly skilled laborers? If there is a sustained gap between desired supply and desired demand that has gone on longer than any significant training lag could explain, it just might be a good idea to think about raising wages to watch people convert out of their pre-existing fields, delay retirement and go into the training pipeline.

Secondly, how rational is it for the typical marginal worker to go into manufacturing right now? It is a declining share of the workforce with significant wage and job security uncertainty and the late teen to early 20s training matrix is not that favorable for this series of professions?