I agree w/ Bill. I go with a two-part catalyzed glazing and spot putty. I learned this from back in my real auto-body days. Mix in equal portions. So the concept is, if you were to squeeze out 1/4 of the putty, then you squeeze out 1/4 of the hardener.
note that the two tubes are not the same size, and therefore you will not be squeezing out the same size qty. to each other. So your golfball sized putty lump will have a much smaller sized lump of hardener.