Has anybody successfully made thier own disolved putty that lasts in a bottle ? What is your formula ? I would like to make my own but wonder if it contains any secret ingredients ?

I have in the past made something like this. I used about half a bottle of Testors Liquid glue, drop in some cut up sprues, waited for them to disintegrate, and then added a little squadron green putty. I don't remember how much sprue and how much putty I put in though, but is did a pretty decent job on seam.

I have some on my desk. I just dumped a bunch of squadron green and white putty into a new jar of testor's liquid cement. Adding some sprue probably isn't a bad idea... I hadn't thought of that. As to a formula, it was just eyeballed.

Since doing that, I've just started using Mr. Surfacer when I previously would have pulled out the dissolved stuff. It doesn't attack plastic nearly as bad. They both smell terrible, but what are you going to do?