Swinging for Divorce…
The walls are all 2x6 and the studs are all spaced 24in apart :)
I don’t know what dew point is… I heat it right now with a propane 30-60k shop heater, but eventually want to heat it with something more efficient and that doesn’t make it smell like gas. Maybe I’ll do a mini split and a wood stove.
I looked at the electric plugs and stuff. They actually all seem to be placed on the outside of the studs.
With regard to dew point: it's the temperature at which water vapor will condense.
What happens is that dew point can rise when you heat air. Combustion creates water vapor and so does your body and breath.
So when you go out to the shop and it's 40 degrees outside but the dew point is 34, all is well. But then you fire up the heater and get to sweating and breathing and adding humidity, the few point rises to say 44, but the heater is keeping the air at 55 so you're comfortable. But the metal siding has only warmed some and is like 42 degrees. Now water starts to condense on the walls. If you're not heating full time, the cars, engines, or anything heavy (like a concrete floor) will take a while to warm up and water condenses on them too.
If the heat is on full time and nothing is allowed to cold-soak to below the dew point, you'll never see it. It's just something to consider. Occasionally warming a spot as you work is not a big deal. But constantly heating and then letting a place cool off completely can start to cause some serious moisture collection.
When you insulate, it helps increase the temperature difference across a material. So instead of your walls being 42 degrees when it's 55 in the shop, the walls are more like 52 degrees and thus much less likely to ever be cool enough to cause condensation. Insulation engineering (r value requirements) are all about ensuring that water cannot find a place to condense out of the air in a place that it cannot dry from. Luckily, local building codes tend to have the math figured out pretty well.
2x6 walls on 24" centers are excellent. Easy to find insulation to drop in there and sheath over. Fiberglass is the cheapest route and is effective, but mice love to nest in it and so the cavity needs to be resistant to them. That's why I'd be sheathing each stud bay first, that and it will help prevent air movement through the wall which is hugely important for a good insulation result. Metal siding tends to be leaky when it comes to air.