I have a project ahead of me with some cabin, bulkhead and stringer repairs and my boat only fits in cold storage area of shop. I’ve used the electric heaters in the past without issues but just thinking of safety especially with the glass work involved. Any better heaters considering?
This will have to run pretty much around the clock at a controlled temperature. If it were just for a few hours a day I wouldn’t be concerned.

if your worried about something catching fire then i would look at an oil filled electric radiant heater....and make sure it has tip over protection.....im not sure how hot you want to get it in there...i would suspect if you need it toasty warm id look at a propane heater to get the temps up before working then shut it off while you work so you dont have any flame/spark there...

I'd look into electric infrared, personally. SHOULD have the least opportunity for a spark.

Should...

if you loose power its good bye heat no matter what you have....the oil type radiant heater will have "some" stored heat for it to bleed off for a little while.....
Electric infrared can heat up the structure its pointing at so that may stay warmer longer depending on what it is...

A nice oil filled heater will work fine for your needs. As long as you have it on solid "footing", I'd have no qualms about leaving it running in the cabin from time to time. Just make a base with plywood and screw in a couple piece of wood around the casters so it stays in exactly one spot. Or ditch the casters, and actually screw it to a couple longer pieces of 4x4 for more stable footing.

Just make sure you use a really heavy gauge extension cord; 10 or 12 gauge. And keep an eye on the plugs for melting.

In the past, I have used a propane torpedo type heater while I'm present, then zero heat when boat was unattended.

Had a space heater fire in my home a few years ago. Had it occurred 10 min later, we'd have not been home and might have been out a home and 2 dogs. and yes, it was in the OFF position.

things scare the **** out of me now. I don't trust them.

Still have flashbacks from the smoke alarm sounds.
Also have 3 fire extinguishers on the first floor and 2 on the 2nd and 3 in the shop.
And 5 new smoke alarms.

I still use them from time to time, but never once leave them plugged in when I'm not within 20' of them. Never. ever.

How did it catch fire when it was off?? A short inside ?

The controls on all those space heaters are **** !! Don't trust them. I had a top brand name one in a downstairs bedroom for guests. Has a motion switch that would shut it off if you or a pet would walk in front of it. Got where it would not even turn on. Thought it was messed up, went downstairs, next morning, it was running full blast and overheated the outlet.

Thanks - I’ll be after one today and yes good call on removing the castors and either screw in appropriate place or mount to horizontal legs.

That’s one of my biggest fears is somebody tripping over the extension cord etc and heat source tipping over. I’ve had a couple over the years that did not shut off when not upright.

Id like a consistent temp of 65-70 deg for the glass work and headliner glue.