Drywall Compound?

Question

What is drywall "topping compound" used for -- how is it different from Plus3 or other lightweight mud?

I'm specifally referring to the SheetRock brand products that makes three types of mud:

1. All Purpose (Green Box) - for tape coat and embedding joint tape

2. Lightweight Plus3 (Dark Blue box) - ???

3. Topping Compound (Light blue box) - ???

Answer 1

I must admit, I've always used standard joint compound for all three coats. But after reading these specs, I can see a clear advantage of the product. It does have a different chemical composition, and seems to spread thinner and be more sandable. Thanks for the tip.

Answer 2

The term "topping compound" can generally mean the material used for the last or finishing stage of the process. According to my experience, i have used "topping compound from start to finish in my "mudding" and texture work. hardly made any difference. I would conclude that you can use it from start to finish. As long as you know how to apply the mud, you will surely come up with a good finish. You can use the exact, specific material for each phase, but if you don't have the right application process and mix, a good job could be a long shot!!!, good luck.

Answer 3

All purpose Green- typically used for step one embedding the joint tape, and prefilling any sizeable gaps prior to joint tape

Lightweight dk blue- used to fill out, or build up over top of the applied joint tape, can be used to completion and mixed for texture applications.

Topping Lt blue- basically same as dk blue, just a lighter composition, and quicker dry/ set time for topping applications, which typically require lighter(thinner) coats and less dry time.

Answer 4

Topping compound is formulated to bond best to existing joint compound (earlier coats). Topping Cmpd sands very smooth to yield best, final finish. Each formulation has different drying rates, workability and shrinkage characteristics. Each weighs and sands different also. A multi-use product is good from base to finish coats. Lite products are usually easier to work and sand but do not resist damage as well. You should consider Gold Bond Building Products manufactured by National Gypsum Company instead of USG. I am biased since I work for National Gypsum. Check out products @:

http://www.nationalgypsum.com/products/?query=cat:3

Answer 5

I am assuming it would be used for your last coat. I just use regular mud and make sure I use three size knives. Use a damp sponge to smooth before you sand each coat. I like using the fiberglass tape and one of those sanding bricks instead of sandpaper.

Answer 6

I use all purpose and then topping for the last coat

with drywall mud, remember "less is best" per a coat.

Jewells
30 months and still here

Answer 7

I believe it is for a smoother finish. I know some guys that say a mixture of, is o.k. too. And also drying times are apparently different.
Personally I would use the topping for much smaller cracks and nail holes and so forth. !

Answer 8

Frankly, there really shouldn't be a difference. I know someone would argue that there's a value to it, but I'd say - interchangable.