I have one of those cheap double 55 gal drum wood stove kits and it works really well.
It sits kind of in the middle of the machine shop and I leave the door open between the shop and house, and if I want the garage warm I leave the door open between shop and garage. It will get to be about 70 in the shop and 68 or so in the house, and something a little cooler in the garage, which is just fine for working.

Otherwise pulling the warm car in the garage and closing the door knocks the chill off a little.
Also have one of those big gray cube shaped propane heaters hanging in the corner of the garage, only ever used it once to see if it worked, the wood stove does a great job so far.

Grigg

•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
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"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-