Spackling paste is used for minor wall repairs such as nail holes and fine cracks. There are a wide variety of spackling pastes, with different ingredient bases such as acrylic, latex and vinyl. Different formulas are used to give the filler more resistance to cracking over time or to make it more comparable with other materials such as paint. Some spackling pastes are designed for specific purposes such as repairing stucco or concrete.
There are two types of drywall tape, a composite paper and self-adhesive fiberglass mesh. Drywall tape creates a bridge between two pieces of sheet rock that are butted together. Fiberglass tapes are pressed directly against the sheet rock, while paper tape is placed against a thin smear of drywall compound. A thin layer of compound is spread over the tape. When dry, a second thin coat of compound is needed because it shrinks as it dries. Once finished the area is lightly sanded to complete the seamless appearance of the wall.
Often the word "spackle" is sometimes used to refer to "drywall compound." However, the two should not be confused, as they are completely different products. To repair larger holes or cracks, theoretically, there should be no problem using spackle on tape. The final decision rests on the spackle's base ingredient, what type of material is needing the repair and the type of paint used to hide the repair. However, if the hole is larger than three-quarters of the tape's width, other solutions are required to make the repair.
Always sand around the damaged area to remove existing paint and ensure good adhesion. Opt for the fiberglass mesh tape, as the self-adhesive quality eliminates the need for using spackle as a "glue" to hold the tape in place, reducing the overall final thickness of the repair. Thinner repairs require less sanding for a smooth finish. If paper tape is all that's available, thin a tablespoon of water-based spackle with a few drops of water. For oil bases, try a few drops of paint thinner to get a brownie-batter consistency. For paper tape, allow the "spackle glue" to dry. Spackle is thick, and applying the product to wet paper tape could cause tears. For either tape, spread the spackle an inch or more beyond the repair, tapering to a thinner application the farther it is spread away from the tape.