can I convert wood burner insert to freestanding?

My dad has an old Timberline wood burner fireplace insert from the early 80's that he is about to scrap. Any chance I can weld legs on this thing, attach some stove pipe and use it to heat my shop or am I wasting my time?

Yes and no. You can most certainly run a stack out the top like a free standing stove. You can also fab up some feet or set it on fire blocks on a concrete or brick mantle. The issue is the enclosure. The front will look fine, but the sides, rear, and bottom are not finished. They are just slab steel sides meant to be hidden and not displayed. I have had my insert for 5 years. Gives out decent heat, but I lose a ton up the chimney. Wish I had a spot for a free standing stove. Maybe the next house!

Yes you can. It might look funny but will be fully functional. Just don't tell the insert that the fireplace was taken away. They have the same 6 or 8" flue outlets that the freestanders do.

I would set it up 18" on blocks for safety and for easy loading.