Just received my sample bag Jason, that was some pretty quick shipping. Everything in there looks great, I think you have a repeat customer here. I'm going to go with what you said and just pour the 4" frog to get used to injection. Call me stubborn, but if everything goes okay with injection on this 4" frog, I'll be back to talk to you about making a 5 or 5.5". I might be a little hard headed, but I think this frog could do great at an even bigger scale. Once again thanks for all the advice and the quick shipping, and I'll be ordering again soon!