In dimensionless analysis, coefficients of quantities which have the same unit for numerator and denominator are said to be dimensionless. I feel the word dimensionless is actually wrong and should be replaced by "of dimension number". For example, the Mach number is of dimension one. 

Many people write, for this case: 


  Mach-Number | Dimension: "-" | Unit: "1"


As mentioned before, I would say 'Dimension: "1"' in this place. But what about the unit? $\text m/\text s$ divided by $\text m/\text s$ is equal to one. But is the number one a unit by definition? Or should one say that the Mach number has no unit and therefore 'Unit: "-"'?


Question: Drywall - final joint compound coat
Answer: Mistake #1. Never use mesh tape with pre mixed joint compound. Mesh tape is for setting type (powder mix) compound. Also never use paper tape with setting type compound.

Mistake #2. Bubble problem. Always make sure that you have a BLEED OUT when you set the paper tape. Bleed out = when you're pushing the tape into the compound make sure you see excess compound squeezing out on sides of the 4" knife. If you don't, then you don't have enough compound on the wall. Pull the tape and do it again.