The calculation for mixing mass ratios is the same for a 5 gram mass,15 gram mass, 5000 gram mass or whatever, it doesn't matter, what does matter is the smaller your mass is, the more accurate you must be in your shop practices to achieve a proper cure, and you are mixing the smallest mass I have ever heard of, so that makes me very interested and brings me to a question if I may ask; what are you applying a surfacing resin too that would use only 5 grams of resin? Just curious...
Bob