Update! Picture Heavy and results of an experiment. Ok so there were some unfortunate things that happened and the paint in a few spots started to crack after i bent them so since i didn't primer the thing i guess that's why. but after a while i felt that Plasti Dip spray makes the foam rigid but it still doesn't get rid of the "grittiness" that is the foam itself and im sure some Foam builders would have noticed. And since I wanted a smoother finish I asked
Aicosu who made awesome DA2 costumes on Deviantart what she used to seal her foam. she told me she used Mod podge. I think Mod podge was mentioned on the forum before but never put into practice since Plasti dip became dominant. So i decided to try an experiment!
(now if you like the grittiness you can disregard this method)
I got some mod podge (gloss type) and put 5 layers over a scrap piece of foam with a foam brush then primed and painted it. The thing had a nicer shine and smoother feel to it then just straight plasti dip. Now For those of you who don't want the brush texture to show up, Mod podge IS wet sandable with 400 grit when you put atleast 5 layers onto it. And with some time and care you can get it as smooth as you want it to. I just didn't wet sand because I was experimenting.
I was able to borrow a nicer camera for my shots to show my results
here is the scrap foam with 5 layers of mod podge and primer and paint
I liked the way mod podge felt so I decided to run another test to see if I could just apply it to foam that was already plasti dipped. Since I plasti dipped my bicep pieces before I was told about the Mod podge i decided use a part of it. On the Left of the bicep is straight Plasti dip then Primer and Paint and the Right side is 5 layers of Mod podge and then primer and Paint. As you can see the Plasti dip side is Gritty and the right side with mod podge is more glossy and you'll have to take my word that it feels smoother
.
So I just Proceeded to Use this Method. Now if you already Painted the armor when it was plasti dipped You can still Mod podge over it, wet sand it and primer and paint.
Here is the Bicep Piece after I Mod podged it and then wet sanded it smoother. then primed and Painted (this was two nights ago)
Today I got time so Here is One bicep Primed and Painted with two coats) then Weathered. Took this shot with one not weathered for comparison.
Now these are shots with both weathered
So im satisfied with the results and I'm going to be using mod podge to seal the foam where i want a really smooth texture. You can Sand and layer as much as you need to get it as smooth as you want it. Be sure to Primer the Mod Podge because it IS water based.
Also if you build enough layers of Mod Podge you can essentially get Rid of seams.
I am now painting my Chest Piece and will Update when its all finished. Hope this Info has helped any New or existing Foam builders.
(side experiment I don't have the pic cuz i lost the scap foam i did it on. I mod podged it wet sanded it and then Plasti dipped over that. The plasti dip retains the smooth texture but then it is no longer wet sandable since when i tried, the plasti dip layer just came off. It might not happen with multiple layers of plasti dip but I didn't want to try)