Epoxy Dams/pour

[Jack Frederick]

I have a piece of Walnut with a large crack open at one end and through the piece. I did a West System pour yesterday and honestly wish I had recorded it. Hilarious I think. What do you do that works and minimizes the side show? The holes through the piece are sealed, but a lot more to fill the back side and open top

[George Yetka]

Controlling epoxy is similar to controlling the tide in Louisianna. It can be done to an extent but it isnt easy.

Tape the bottom and side well with something like Tuck Tape you need a perfect seal. The top you can use caulk to make a dam. If any of tape loosens or a spot is missed you will most likely lose everything. Once the dam goes you are very lucky if you can stop it.

[Kevin Jenness]

You may better off using caulk or hot melt glue rather than tape.

[John Blazy]

Uncured epoxy will drain constantly without filling the void, unless COMPLETELY sealed. My trick is to heat the wood with heat gun to do several things, assuming you are using general purpose, fast cure epoxy like a tabletop epoxy:
1. off gas air out as heat expands the air in the wood, then during cool down, wood creates vacuum, sucking the epoxy into the wood.
2. The heat lowers the viscosity of the epoxy exponentially, thus the watery epoxy soaks in alot
3. The heat kicks off the cure from a couple hours to minutes - this is what you want for sealing allowing final fill without DRAIN.

Keep heating gently til epoxy sealcoat is nearly hard and tacky, THEN tape dam the bottom and vertical edge.
Then mix new batch and pour it into crack. It will fill fine, then de-bubble due to wood still being warm

[Jack Frederick]

Thanks! Great info. Have to say, George knows his tide charts;) Round two today. I left the piece right in front of my new shop heater and warmed it for a few hours. Use waxed paper doubled for back up with some mdf pieces at the end. I thought the thru crack was filled but a bit leaked through. The epoxy set up pretty well with the heat and is stable. I’ll sand off todays mess and do another round tomorrow. I’m gaining on it. Again, much obliged for the directions.