Walls and Ceilings - taping and spreading questions

For taping sheetrock should the tape when finished be covered in joint compound so you cannot see the edge of the tape or is it ok to see the edge of the tape. Is the purpose of applying two coats of lightweight j/c or j/c over tapes simply to just level out the surface or is there another reason like covering the tape with lightweight j/c or j/c to make it more structurally intact.

Also how much more spreadable is lightweight all purpose compound compared to all purpose compound. Any tips on what the best consistency is. THanks.

Cover the tape. You would not believe the flaws that might be seen after you paint, so you want to cover them as much as possible. Be patient with this step... we got too impatient once and rushed through it. It took 1 1/2 months of sanding to undo what two days of hurry-and-mud did.

The tape is never completetly covered with the first coat of mud. Too much mud applied to wet tape can cause it to come loose :eek: It normally takes 3 coats of mud to completely fill and smooth out the joints.

I don't do enough drywall work to really answer the benifits of lieght weight mud, I think it may sand a little easier. Mixing and thinning slightly, makes j/c easier to spread.