Every listing in this category talks in ounces. A crack is a volume, so the useful figure is cubic inches of mixed putty, and it takes one multiplication to get there.
Density does the conversion. The 2-part set runs 130 lb per cubic foot, which works out to 0.83 cubic inches per ounce and 11.7 cubic inches for the 14 oz set. The sticks are lighter at 118 lb per cubic foot, so 0.92 cubic inches per ounce.
The result adds 15 percent over the raw void. Some putty stays on your gloves, some gets pressed out past the edges, and running short halfway through a set is worse than having a stub left over.
Weight on a pack tells you what you are paying for. Volume tells you whether the crack gets filled. Density converts one into the other, and both figures are on the data sheets.
| Product | Density | Cubic inches per ounce | Yield per pack |
|---|---|---|---|
| 14 oz 2-part set | 130 lb/cu ft | 0.8308 | 11.7 cu in |
| 2 oz stick | 118 lb/cu ft | 0.9152 | 1.83 cu in |
| 4 oz stick | 118 lb/cu ft | 0.9152 | 3.66 cu in |
Fourteen ounces at 0.83 cubic inches per ounce comes to 11.63. Our sheet prints 11.7, so the two agree and we use the printed figure.
A crack you have not chased out yet is narrower than the one you are going to fill. Grind or scrape it to at least an eighth of an inch deep, then measure what you actually made.
Cracks taper. Using the wide end for the whole length overestimates, which is the direction you want to be wrong in.
A twelve foot crack that is wide at one end and hairline at the other is two measurements, not one. Add the results.