Every resin has a mixing ratio. The ratio is how much of Part A to mix with how much of part B.
And then there is the fine print. The wuh? Yes...the Fine Print. Fine Print is what we dont see because we think we know it all. And then all of a sudden everything goes kerfluey and we dont know why. Because we didnt see and read the Fine Print.
The Fine Print says...Mixing Ratio "X amount" of A: "X amount" of B......and this is the important part...By Volume "X amount A: "X amount" B by Weight.
And some resins, MOST in fact have 2 ratios. 1 ratio is for WEIGHT and 1 ratio is for VOLUME. The weight ratio is the one that is usually the weird ratio. 100:80 or 100:90. The volume ratio is usually closer to a 50/50 or 1:1 ratio. Last week or so when I first made the Roboid molds I was having issues with my urethane resin. Why? because I was confusing the volume and weight ratios. I was trying to measure the weight and instead adjusted the volume and it impacted the resin in a negative way.
You cant measure weight with measuring spoons. Measuring spoons measure volume. And thats exactly what I did...or attempted to do.
Since I dont have a scale, I have been measuring by volume. When you get the volume ratio right, the weight ratio will be correct and visa versa.