Build advice needed - photo heavy

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So I’m working on my first foam armor build and chose to do a Mandalorian helmet. I’m struggling to get it to look clean / crisp / smooth. I got the foam pieces glued and then treated the seams with Kwik Seal putty. After that I gave it a coat of Epsilon Epoxy and let dry overnight. This was my first time working with the epoxy (aside from a trial piece / seam to see how well it worked). After priming with grey I noticed several drips.

what can I do to fix this and fix the edges on the side details? I sanded it again down to the foam in some areas. Here are a couple of pics, any advice / help greatly appreciated.


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I am not entirely familiar with he Epoxy you used so i cant speak to if this will work. The helmet appears bowed out at the front which could have happened as the epoxy dried. If you do anything that involves a hardened shell around a foam build you should try to brace it in its final desired position first. Some strong tape pulling the insides together or even some thread sewn inside to pull the mandibles to the desired placement are good options.

I normally use fiberglass resin as a strengthening coat with my helmet builds. First spray the whole thing with a black primer to get good visibility on imperfections. Next add the resin (or maybe epoxy). You should apply it very lightly and maybe 2 coats at a time. let it dry completely and then isolate and sand problem areas. Once done apply another coat of resin and repeat. Once the helmet sets into its final shape you really cant do much to change that without risking the rest of the piece.

In short, reinforce the shape and use more coats of epoxy but in smaller quantities.



Well-Known Member
In past I made many Halo costumes from eva foam 8 mm thickness . More than 8mm is to much in my opinion for making shapes . I used Pepakura designer and was cutting bending lines exactly like in obj file showing in software to have same shape and then just used hot glue to put in this undercuts from inside.

I used PVA glue with water and painted around 4-8 layers outside and wet sanding to make it smooth. You can replace PVA with Polyurethane resin like easy flo 120 or smooth on casting resin for cosplay items. It is important to apply resin on raw eva foam so resin will fill ait bubbles and will make stronger bond with eva foam. I used this method with my first eva foam Samus costume for somebody.
Using bondo and bondo mixed with resin is overkill for me. Will be heavy and will separate from helmet if you will bend or hit the helmet.
You can use casting resin from inside with poly paste 2 to make it stronger but be sure to use something to secure shape of the helmet or just go piece by piece with thin layers only . The best is just hold your helmet up side down and use a little bit of casting resin inside . Shake it around and hold the shape of the helmet or use hot glue with cardboard to keep helmet in shape when casting resin will be hot .


Master Member
Yeah, Bondo will definitely crack if flexed that much. Epoxy will be a little better. You may even be able to correct the bow-out. Use an Exacto knife to cut slits down the front and then use whatever you can to internally flex the cheeks inward. The Exacto knife slices will open up and then you can fill the cracks in. Depending on how the epoxy cures, it may cause the cheeks to bow out a bit, so ensure you compensate for that by bringing in the cheeks a bit more while bracing.
I'm not sure how much work you put into this, but sometimes it can be better to start over rather than saving a piece that has numerous issues.


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