I cut it twice and it's still too short.
Generally speaking, spackle is a product used to fill small holes, cracks and blemishes in drywall and plaster surfaces. It is usually painted afterward. Joint compound is generally used in conjunction with mesh or paper based tape to cover panel joints between sheets of gypsum board.
As I recall, spackle is formulated to reduce shrinking and therefore less likely to crack when it dries.
I painted houses for a few years and when I started I asked this question. I got contradicting answers from almost everyone, so I gave up, did what I wanted, and figured things out from that.
What I do now is for myself, in other words, I don't have to be as efficient as I can possibly be. For depressions and narrow shallow cracks and holes, and the edges of plaster board I've put in to fixed a section of an existing wall, I use premixed joint compound: the stuff spreads and feathers beautifully and can be smoothed out with a wet sponge when it dries, eliminating all or most sanding if you've been reasonably careful. For larger and deep holes, I'll use plaster that I've mixed up from powder; for in-between-sized holes I'll use plaster or spackle. I make sure that I keep the plaster or spackle below the plane of the surface I am working on and I don't really care if they crack, because once they are dry, I use premixed joint compound to finish the surface.
The main problem with the premixed joint compound, as compared to plaster and many spackles, is that it takes quite a while to dry. I usually wait a day before smoothing it out and putting on another coat. Depending on how obsessive-compulsive I feel about the repair, I might do as many as four increasingly feathered-out coats to make the repair just about invisible.
I cut it twice and it's still too short.
Sometimes being an old fart has it's uses
Joint compound is on the high side of the pH scale.
Spackle is pH neutral.
This used to be a big deal when oil and alkyd materials were still used on walls. Joint compound would "burn" through oil. Spackle wouldn't.
Anymore, with latex and other waterborne materials being the norm, there's no reason to not to use either/or.
Ironic ain't it?
I have used the small and expensive tubs of vinyl spackling compound to fix drywall damage in my house and found it to be well worth the extra cost. It does not shrink and crack when it dries like "sheetrock mud". It fills gaps better and is easier to work on small areas. I forget the brand, but it starts out pink colored and dries white. Good stuff.
Just to put one more monkey in the barrel...
Setting type joint compound (called durabond in my area) fills wide gaps and larger voids without much shrinking because it cures chemically like concrete, not through evaporation like regular sheet rock compound. Down side is it dries much harder than either spackle or compound, very difficult to sand and will not sponge out once cured. I use it as a first rise to fill serious voids and cracks in plaster, cover it with a thin rise of something else easier to sand for top coat.
Peter, Durabond is a type of setting compound. There are versions that, when cured are "easy-sand", like "ready-mix" joint compound. They come in different set times, too--5, 20, 45, 60, 90, etc. They will harden quickly, but may remain "wet" for some time, but can be sponged out after they get hard (and I've even painted them right away with no trouble). It's been so long since I've used it, but IIRC, Durabond uses cement rather than plaster of Paris for its setting ability, and may also have some small aggregate in it.
Jason, I have to look for that sandable type. I've been slowly repairing plaster walls and ceilings in my old 1900 cir bungalow for several years now. Usually use durabond 45 because its about as fast as I am. I typically fix lathe and key failures with plaster washers, grind mising pieces back like a dovetail key, then come up in several rises with durabond, scratching surface keys into the almost set surface to hold the next coat. The stuff I've been using sets up like concrete in about 2-3 hours and resists sanding or sponging, so I always finish with regular joint compound 'floated" with an old just damp grout float to achieve that polished texture of the original lime coat. Total rise from lathe to lime coat is about 15/16". Love to find an easyier way.
Durabond is, I believe, a USG product, and comes in a brown paper sack with red and green printing (yep, just checked it out: http://www.usg.com/navigate.do?resou...t_Compound.htm ). The easy-sand stuff comes in a white paper sack with red and blue printing : http://www.usg.com/navigate.do?resou...t_Compound.htm
From what you describe, though, you're probably doing it the best way short of using actual plaster for the repairs. You could just use the easy-sand as your top coat or two after you build with Durabond. The nice thing with any of the setting-type compounds is that you can adjust their viscosity by how much water you add, mixing a very thick batch if you have a deep recess to fill, then mixing progressively thinner batches for successive coats.
P.S. Those are different links above, the software just automatically snipped the long pathnames.
Thanks Jason for the link...and yeah..real low slump for ceilings...figured it out when the first attempt came down wet on my head like a spinning pizza!