A river table lives or dies on the clarity of the pour, and almost every failure — cracking, yellowing, cloudiness, shrinkage away from the wood edge — comes down to fighting the resin's chemistry rather than working with it. Deep pours generate far more heat than a thin coat, and most of what goes wrong traces back to that heat being managed badly.
Why You Can't Just Use a Standard Casting Resin
MAS Deep Pour Casting Epoxy is a 100% solids, 3:1 system built specifically for this job, with an extended gel time that reduces exotherm and improves air release compared to a standard casting resin. That extended gel time is doing real work: a thinner casting resin poured too deep will heat up fast, and that heat is exactly what causes cracking, yellowing and shrinkage in a thick pour. Deep Pour cures in 24 to 36 hours at 70°F to a clear, glass-like finish that resists both scratching and yellowing over time, but only if you respect its pour depth and temperature limits.
Respect the Pour Depth
The maximum pour depth is 1 to 2 inches per layer. For a river table with a deeper void, step-pour in 1-inch layers rather than trying to fill it in one go, and let each pour cool back down past its peak exotherm before adding the next. Between pours, once the layer has cured, lightly sand the surface and wipe it clean before pouring on top — this gives the next layer something to key into and helps avoid a visible line between pours.
Watch Your Temperature
Ideal working temperature is 65 to 80°F. Don't pour above 80°F: higher temperatures speed the cure up and are a direct cause of discolouration, shrinkage and cracking, which is exactly what you're trying to avoid. If your workshop runs warm in summer, pour earlier in the day or cool the space down rather than pushing ahead in the heat.
Seal the Wood First
Wood needs to be completely dry before you pour, and porous timber should be sealed before the epoxy goes anywhere near it. Our Deep Penetrating Epoxy Sealer is built for this step, and skipping it is one of the most common causes of air bubbles and foaming as the casting cures — trapped air and moisture in the timber has nowhere to go except up through your pour.
Different Job, Different Resin
Deep Pour isn't the right choice for every casting job. If you're building up a thick, glass-like finish on a bar or table top in a single pour rather than encapsulating a void, MAS Table Top Pro Epoxy is built for exactly that, with published coverage rates to help you work out how much you need for a given depth. If you're working on resin art rather than furniture, MAS Art Pro Epoxy's 1:1 ratio and 60-minute working time at 75°F is the better tool for the job.
This is an advanced system and it rewards planning your pour volume properly before you start. If you have any questions about a specific project, get in touch at sayhello@epoxy.ltd.
