Heat the resin in a warm water bath. Putting the sealed bottles in a warm water bath for 10 or 15 minutes can help make the resin thinner and help any bubbles rise faster. This is important if it's below 20–23°C (70–75°F) which most resin needs to cure. But, be warned, heating the resin can lower the working time.
Mix slower. Less vigorous mixing means you will introduce fewer bubbles – take your time and move slowly.
Wait 10-15 minutes before pouring. You’ll want to wait anyway, but giving the resin time to settle after mixing will allow any bubbles to rise to the surface. Pop them with your long neck lighter.
Spread resin inside the mould before pouring. Get the resin right into the corners and numbers with a soft brush. By pushing resin into these areas, it may prevent bubbles catching and wrecking your casting. Don’t use a sharp object like a toothpick!
Dip any inclusions in resin. Items such as dried flowers have plenty of spots for air pockets to form. Soak in resin for a few minutes and stir them to dislodge any bubbles.
Squeeze the mould a few times while pouring. This can help dislodge some bubbles caught around the corners and numbers.
