Plastic Additives

Okay guys during the summer I will spend a good bit of time chasing stripers in my local waters. This year I made the commitment to go all artificial as that live bait can get pretty expensive. Now that I am knee deep in it I have created some "POP" molds to go along with the jig heads I pour. My problem is that all of my crappie plastics are too soft for the striper baits. I want to stiffen them up. Can I add hardener to the already made plastics or does it have to be added from the jump? I am going to buy some more plastic soon as I am down to about 1/4 gallon now. Do you think I would be better buying regular and adding hardener or just buy the hard? I will be using the Caney Creek plastic because of its ease of use. I will also be getting some more soft from them form my crappie stuff. FYI if you start pouring big baits break out the wallet. Them things take a but load of plastic. May have to shift back to pouring crappie baits but the tackle boxes are over full. I have an addiction I can not shake.

Thanks for the advice in advance.

You have to add it To raw plastic. Meaning stir the hardner in before you cook it. Be sure to mix it really well. You might could get by with just buying medium plastic dePending on how hard of a bait u want. Might could save u some money by just gettin medium also. Ha but then again if u truly need the hard you will wish u bought hard instead of mixing in that much hardener to medium! Hope this makes sense!??

thanks