How can I get latex-like finish on my foam sword, and avoid biggest pitfalls with applying latex at home?

Question

I'm in the process of building my own LARP weapons, using EVA foam on glass fiber core. Construction itself, and sculpting, luckily won't be a problem for me. Problem will be with coating.

The industry standard nowadays is pigmented latex, painted. It looks really great when done in a shop or by an experienced crafter. When I do it, I have following issues:

• Underlying layer of glue is either visibly uneven or too thin in some places to grasp the latex.
• Latex tends to drip, bulge up, roll on etc. as I go.
• Brush marks are hard to avoid.

I'll Be only making a few of those so I'd rather not buy an airbrush.

Is there a material that would give me a coat comparable to professional one, using simple tools? Or a way to make latex easier to work with?

Answer 1

There are various ways make the latex easier to work with and to avoid the issues you list above. These are all from 20+ years of personal experience and recommendations from my friends and UK Kit Makers:

1. I don't personally put a layer of glue on the outside of the weapon as it makes it easier to strip if you need to do a repair at a later date, but I remember my friends who did using thinners to make their Evo-Stik coat much more paint-like for application. That should allow for a much more even base coat.

2. and 3. When applying layers of latex, less per layer is better. You're looking for a thin, even layer - most of the weapons I've made have had between 8 and 12 base layers (normally black) put on before I get to doing colours or metallics.

   • Let your layers dry completely between coats - yes, this takes a little while, but if you have a few weapons to do at once, by the time you finish a layer on your last one, your first is probably ready for the next coat.
   • It also helps a lot if you use a decent brush. I normally use 1" or 2" bristle brushes - not the incredibly cheap ones that shed as soon as you look at them, but also not the horribly expensive ones. I spend about £3-4 on a brush. Clean them between uses and rinse them out between layers as described below. Don't let flecks of dried latex build up on the bristles - you can use a cheap comb to get them out.
   • When you are applying latex, have two pots of water with a little washing-up liquid added. Wash your brush in one of them, and shake it/pat it dry before dipping in the second. When you take it out of the second, scrape off as much of the liquid as you can on the edge of the pot before dipping in the latex. You're using this as a flow agent, to stop the latex sticking to the brush and to help it go on smoothly.
   • Don't make your latex too thick. It should be about the consistency of cream and flow smoothly. Equally, don't add too much pigment to the latex. I normally use about 5-10ml of acrylic paint to 500ml of latex.
   • Don't dunk the whole brush in the latex. The top half-inch of the bristles should be fine - just keep picking up more when you run out on the brush, and dip in the flow agent pot first. This should stop the runs and drips.
   • If you can, hang the weapons up so they hang tip down, and work down the item from the hanging point towards the floor. Runs and drips that do occur can then be seen more easily and caught and removed with the brush and latexed over properly.

Add to that another vote for HexFlex as a replacement for Latex - I was put onto that by a friend who cosplays and makes her own LRP kit, and the finish is durable and flexible. I used it on some of my own kit which takes quite a beating, and they are holding up nicely.

Hope this helps.

Answer 2

Where possible you can use Plastidip Spray as a base layer. After two coats of a base color applied in an even layer, you can then move to the painted latex to get exactly the color you want. Finish with a clear coat of latex spray.

Alternatively you can get a paint product called Hex Flex. It's meant to be painted directly onto foam. I've used it on XPLA (Cross Linked Polyurethane) foam with good effect. Then used a sealant of clear spray latex on top.

Pictured are three shields, two of which are painted by me. Left shield was professionally painted at B3is, who also constructed all the shields. The buckler at the bottom was painted by myself with multiple layers of brown, grey and metallizer Plasti-Dip spray. The shield on the right side of the picture originally had Yellow Plasti-Dip spray, but the yellow color is Neon and hideous. So I covered it with Hex Flex to correct the color as much as possible. If I were to build it again, I would use the Hex Flex directly on the foam for much better results.

Answer 3

It has been quite a while since I last did this, but...

I'd say that it really depends on what type of weapon you are making. When I did this, we were making staffs, and visible brush marks really wasn't a problem, as it helped with the whole "wood" look.

We did not have any real problem with the latex adhering to the foam (basic grey pipe insulation foam), but we (from memory) used a pretty light pigment load for each layer. All in all, I think we put 3-4 layers of latex on. I do not recall us doing any preparation of the foam prior to the application of latex.