Holty40,
You have to be insane to want to give ctc/oaa 100k, secured against your house. Come on..my gawd!! Get a grip on what you intend doing to your family. Bankrupt comes to mind.
Your son is young enough to go modular and when things pick up he will be debt free and able to pounce on any job offer (even the low paying ones) as he will likely still be single and without dependants. It aint rocket science.
Get him to do a ppl first.