I would say you are a long way from renting space and hiring employees. When you are working 16+ hours a day 7 days a week out of your garage and still can't keep up with the orders is the time to think about taking on an employee. If you're not willing to put in 16+ hours a day, then work for someone else and run a hobby shop out of your garage part time. Take this from an old guy who has been there and done that. 40 or so years ago I expanded too fast and it was the biggest mistake I ever made. I was lucky in that I was able to sell out and pull back into a more comfortable zone. The guy that bought my shop went bankrupt about a year later due to an economic downturn.
Taking on employees is a big responsibility, now you have another mouth(s) to feed, you have to keep your employees busy, meet payroll and it adds another layer of complexity to your operation. Hiring from a temp agency is a good option, but don't lock into any long term (90 day) contracts with them, hire day labor. You also have to ask yourself if you want to be a machinist and run a machine, or drive a desk.
I could write a whole book here but the major points in no particular order:
- Do you have enough work to support paying rent?
- Is your equipment paid for?
- Is steady work available?
- Are you willing to put in the time to run a successful business? Are you willing to have no life while getting started?
- Do you have enough savings to pay the rent for 6 months if the work slows down?
Above I have focused on the negative. I do have to say that running your own business can be very rewarding, but work into it slowly. Don't borrow money to buy equipment, pay as you go.
Best of luck !