The Difference Between Spackle and Drywall Joint Compound

I believe spackle has plaster in it which is meant to dry faster and harder   Spackle is used to patch holes and imperfections  Joint compound is made to go on in small coats and be supported by tape or cover screws  It is made to take longer to dry to be able to smooth it better

There is a host of different drywall compounds available, both fast drying and the stuff that does take quite a spell to dry.

Spackle is harder than joint compound and dries faster IMO. Joint compound is designed to flow over sheet rock joints that have been taped and also can be used to fill small glitches on the sheetrock. Spackle is designed more for major patching, it can be put on thickly and it will still set, with joint compound if you put a large amount on it is likely to crack and flake, not designed for that.

Spackle can be harder to work with, lot harder to sand IME. They have a light spackle these days that may be a kind of compromise, it seems to dry quickly, it can fill big areas without cracking but isn't as hard to work with as traditional spackle. I haven't tried it for scenery, so I would recommend trying  it as a proof of concept before getting a lot of it

A small twist - I prefer joint compound over light weight Spackle for mortar lines. It goes on better and when I clean it off the stuff stays in the mortar lines.

So when it came time to fill in the seams of homasote on my layout it is what I had and it is joint compound. So on it went and yea the next day cracks every where. Got to be my technique since it looks good on dry wall...............

Joe