When I do doublets or triplets I have a procedure to reduce the bubbles. I clean both surfaces to be glued with denatured alcohol then place them under a 100 watt goose-neck lamp to heat them up. When they become quite warm to the touch, I then mix the Epoxy 330 on a piece of white paper with a small stick. When mixing the two parts do so by a swirling action, not by whipping it together. Do it slowly so you don't introduce any bubbles. Keep swirling it together until you see no more swirl marks. Be sure to bring the edges of the mix into the center so no unmixed material is overlooked. By mixing on a piece of white paper you can see the swirl marks better. Place the mixed adhesive under the lamp alongside the heated pieces and warm it up for about a minute. This makes the material thinner and more fluid. If there were any bubbles introduced in the mixing process they will now float to the surface where you can pop them with a sharp point. Using a small flat wood stick (found at craft stores) and pick up some adhesive and slowly spread it on one of the stone surfaces. Do not dab it on, this will introduce bubbles. When the surface is fully coated use the edge of the stick and draw it across the surface once to remove the excess adhesive. Do the same application process on the other stone. Place the edge of each piece together and close them together like closing a book. This will prevent trapping any bubbles between the pieces. Press them together between your thumb and forefinger and move them very slightly to squeeze any bubbles and excess adhesive out. When you feel the pieces start to drag against each other stop squeezing them and place the glued piece under the light for a couple hours. This will speed up the curing. I always let the piece cure overnight before doing the cabbing process.
