In my area, in the sheet metal union, internal union politics instead of skill plays a huge role in whether or not you work those hours during economic downturns. The BA's can either leave you alone (not do anything either way), help you or hurt you. Your "union brothers" can do the same. When it is busy, the demand for bodies will sustain employment.
When you hit 50 around here, work starts drying up. Companies will not hire you unless you are well established or have some help from someone already working there... or politics.
Many well qualified, hard working and decent people that I know have been forced into early retirement, at a substantial penalty, because they can't get a job and would be ineligible for that union subsidized health care because they aren't working enough hours prior to retirement.
Once you retire, there are clauses that trigger revocation of benefits if you take a job to supplement your income. The list of prohibited jobs/fields is long.
All of those things that appeal to you as a potential union employee are available to you as a business owner. If the business is viable, you would be a fool to toss that aside and go union as an employee.
Stop bumping heads with dad, pay attention and show an interest in taking over and growing the company. That will get you further than a union card.