docholiday78 came up with a really good method for getting a shiny finish while keeping the foam flexible. I went ahead and followed this method on some test pieces and it does work quite well.
Here are the steps that docholiday came up with:
Step 1. Heat sealing the foam. If you dont have one you can try a blow drier. Heat but dont burn it just till foam looks like it has glitter on it. Do it twice but let cool in between.
Step 2. Modpodge time. Coat as needed but no less then 3 coats. Look closely at the foam coat until pores are filled. The pores on the foam are the little dots on it that absorbthe coating. Youll know when sealed good when no more dots And have shine like. Let dry for 30 min
Step 3. plastic dip 2 to 3 coats. no less then 2.follow directions on label for amount of time to wait in between coats.
Step 4. Adhesion promoter 2 coats and let dry.
Step 5. Filler primer. Heres where youll be able to tell if ya followed directions cuz itll be really flexible. After the first coat ya can lightly wet sand with 800 grit. If not proceed to next step. If you sanded make sure its cleaned before next coat.
Step 6. Paint foam. Preferrably a duplicolor paint but if ya cant find your color any paint shoud be fine. The first pic is of it painted only with barely one coat. didnt have enough oops lol but paint your with 2 coats and let dry after and in between.
Step 7. Is the cherry on top. 2 coats of that glaze it will make it scratch resistant and super shiny. I put examples of how flexible it is and returns back to its original form. Wait about a week then wetsand with 2000 for smoothin out any orangepeel if ya have some . Then polish compound, wax n buff n it should be oh so smooth n shiny like a brand new car lol n thats it your done.. pretty easy huh...enjoy
The steps are laid out in his thread along with pictures:
http://www.therpf.com/f24/foam-rondo-abs-weathering-149883/index8.html