The plastic should be folded over the bottom of the plug and stapled on before heating.
The top can be screwed back on and a hole put in it to use compressed air for removing it from the plug.
Top-Flight paint is too tranparent and you can see right thru to the underlying color of the bottle so use clear bottles if possible otherwise paint with Rustoleum.
Contrary to a previous post about being flimsy I find them very tough and resilient just like the pop bottles they come from.
http://www.theflyingknights.com/phpB...topic.php?t=72
.