MIXING EPOXY.
I use aluminum filled Devcon epoxy. My experience with it is that the
mixing ratio of epoxy to hardener is not as critical as with other
epoxies.
The easiest to use epoxies are those that come in side by side
syringes. Te are designed to discharge the correct amount of
hardener and epoxy.
MIXING BY VOLUME
I use an artist palette knife to remove epoxy from the container and
place it on a small 4 X 4 kitchen tile. I work the epoxy until it
forms a long uniform bead on the tile.
Wipe the palette knife clean and remove some hardener from its
container. Place a bead of the hardener next to but not touching the
epoxy bead on the tile. Work the hardener into a bead similar in the
size to the epoxy bead. Eyeball the amount of hardener that is
required by volume to mix with the epoxy. The remaining hardener can
be placed back into the container.
Mix the hardener and epoxy with the palette knife. I normally wipe
the palette knife clean then mix the mixture a little more. I do
this because I feel the ratio of epoxy to hardener on the surface of
the knife may not be correct.
MIXING BY WEIGHT
If you have an accurate scale you can place the tile on the scale
and tare its weight out. Place epoxy on the tile and note the weight.
Calculate what the weight of the combined mixture should be. Add
hardener next to but not touching the epoxy on the tile until the
scale reads the correct combination weight. Wipe the palette knife
clean then mix the epoxy and hardener.
Place the excess mixture of epoxy on a paper towel. The excess can
be used to determine the cure of the mixture.
You can clean the tile and the palette knife with alcohol and a paper
towel.