Foil doesn't cause hot spots. Your light does! Any reflective Mylar worth a shit is about twice as 'good' as foil at making intense hot spots. Foil is 50% diffuse while reflective(aluminized) Mylar is 25% diffuse. Reflective Mylar has a higher clarity, more mirror-like reflection. The more mirror-like, makes a higher intensity reflection more possible. Like laser applications, they use some of the best mirrors made(nearly 100% reflective). Or there's flat white paint... which is impossible to use for a solar oven... and isn't used in any practical application to reflect light for plant growth. There are other forms of white paint that are... but they're still not very popular.Yea, scrap my stoner plastic idea, you should go for a mylar, even if it's hard to use, try not to use foil as it causes hot spots
Glue is the best, IMO. Brush the glue on evenly, get a clothe to make the aluminum smooth.I have some double sided tape i'm gonna try...if I could get this mylar to work good, then that would be a lot easier because I got 2 huge rolls of it already. If double sided tape doesnt work, should I just put 4 small piece of cardboard on each side of a strip of mylar and then staple it into the tarp (wooden beams are behind the tarp).