Urethane recasting

[Incognitouk]

so i am looking to do a second cast onto existing cured urethane do i need to prepare the cured urethane with anything or will the two just bond?


or do i need to do the second pouring before the first has fully cured?

 

[Sylvanite]

Fresh polyester resin will not chemically bond to cured polyester resin. The cured resin needs to be scuffed first (give it some "tooth") to permit a mechanical bond.

I've been told that urethane resin, however, will bond chemically to cured urethane resin. I haven't done it myself, but it's worth trying.

I hope that helps,
Eric