Foam Sealing Methods.

[ferret304]

Hi guys,
So I'm back with another question... And it's about sealing foam. What ways are there of doing this? I've heard of Plasti-dip, but in Australia it's ridiculously expensive (as in $30 for a single can), so I'm looking for alternatives. Thanks for the help,
Ferret304

 

[Spartan 420]

Hi guys,
So I'm back with another question... And it's about sealing foam. What ways are there of doing this? I've heard of Plasti-dip, but in Australia it's ridiculously expensive (as in $30 for a single can), so I'm looking for alternatives. Thanks for the help,
Ferret304

PVA glue. I had a look around and read up on the stuff, on the back of my bottle it actually says "Can be used for sealing of porous materials by mixing 1 part with 5 parts water." I've seen people brush it on using high quality varnish brushes that don't leave streaks, and some people use strait PVA up until the last coat. I'd suggest doing this, then doing one layer of 1 part glue, 1 part water. For a nice finish you can use plasti-dip to use a light coat, and despite its price you will only need about 1 can. A suit coated in nothing but plasti-dip can require sometimes up to 10 cans.

There's a tutorial around, I'll look for it but you should be able to find it with the search tool.

-S420

 

[MissingSpartan7]

Hi guys,
So I'm back with another question... And it's about sealing foam. What ways are there of doing this? I've heard of Plasti-dip, but in Australia it's ridiculously expensive (as in $30 for a single can), so I'm looking for alternatives. Thanks for the help,
Ferret304

About 3-4 coats of PVA/Wood Glue mixed with water in a 1:1 ratio will probably do it.
That's predominantly what I've been doing for most of my own foam builds. By the time you get to the 3rd coat, the surface is pretty good.

 

[Dorvack]

About 3-4 coats of PVA/Wood Glue mixed with water in a 1:1 ratio will probably do it.
That's predominantly what I've been doing for most of my own foam builds. By the time you get to the 3rd coat, the surface is pretty good.

Do you mix washing up liquid in with your PVA / water mix?

When I've used PVA mixes in the past for modeling, the addition of a tiny (and I do mean tiny) drop of washing up liquid aids with the flow of the mixture into any tight spots.

 

[MissingSpartan7]

Do you mix washing up liquid in with your PVA / water mix?

When I've used PVA mixes in the past for modeling, the addition of a tiny (and I do mean tiny) drop of washing up liquid aids with the flow of the mixture into any tight spots.

I'd never heard of doing that actually - I might have to test that out at some point...
A 1:1 ratio is usually quite fluid though - the water really thins out the PVA, so it doesn't really have any issues getting into small spots. I just paint it straight on with a normal brush. The only issue sometimes, is getting enough into the gaps to fill them - but I might use a thicker mix (2:1) for that.
It might have a benefit adding a drop into ratios 3:2 upwards (on the PVA side).

 

[harican89]

yeah. pva wood glue, or pva resin is good for sealing. most of the guys use plastidip (sprayable rubber) for a sealling... but plastidip is expensive and compared to the result of wood glue not worth the money.

here is a simple video i made up month ago. hope this helps you out. in the video i dont mixed up the wood glue with water because i dont believe that the water dries so quickly like the wood glue needs it... but give it a try ^^

And here is one example result:

 

[BuildsByBaz]

I painted straight PVA wood glue onto the waist area of my Iron man suit. Unfortunately when you bend it, it cracks badly. What can I seal the foam with that will take paint and still flex?

 

[Carpathia]

Try an epoxy resin, the type that does not create any heat while curing. I've recently attempted using this on a new set of Mk VI boots and had success with it. I'm not sure what type is available in Australia, but make sure it's not a polyester resin.

Coating the foam in an epoxy resin will also give you a nice base and the ability to add body filler if so desired. Just make sure to lightly rough up the surface of the resin with a piece of sandpaper. And make sure that any piece you wish to use filler on is an area that will not flex much.

 

[harican89]

Try an epoxy resin[...]

wooop woop woopp....
first of all... no epoxy resin or other resin as a sealing method... this doesnt work. its to hard and will no longer be flexible or its cracks at the right moment you tries to bend it.

I painted straight PVA wood glue .... Unfortunately when you bend it, it cracks badly.

the other thing is the flexiblity of wood glue... how thick was your layer? in my video i painted 2-3 layers and let them dry complet. the layer was about a half milimeter thin and its totally flexible. what exactly cracks? the wood glue layer or the paint above?
if only the paint cracks then you use a diffrent kind of spraypaints. acrylic and nitrogen paints are flexibile enough to resists the bending of the armor. take a look at the end of my linked video.

 

[elusch99]

So I see that a lot of people like PVA. I had never actually heard of it, so for my ongoing build I am using mod podge. It's pretty cheap, but you have to be sure to spread it out well, otherwise you get streaks. It makes a great surface for painting, too, and you only need one coat.

 

[harican89]

referencing to this site mod podge isnt waterproof... on the other hand its a also a glue like the pva (which is normaly the abbreviation for polyvinyl acetat and is a content of white wood glue. i would go with white wood glue (waterproof), but you can use mod podge as well... the price plays an insignificant role because wood glue costs 8$/500g

 

[statiktv]

PVA works great. It's NOT the same as all wood glue. Yellow Wood glue isnt flexible and it cracks when bent. PVA is. Its the same stuff used for book binding and i bought mine on amazon. The 1:1 waterdown ratio makes it a bit too liquidy for my taste and the only reason (that i know of) to water it down is to eliminate brush strokes. I use a little less than 1:1, more like 1 part glue to .5 part PVA. 3-4 coats should do it. Then male sure you let it dry for at least 24 hours to cure. Ive had some peel off due to overly sticky painters tape before, so dont be hasty. I skip the plastidip entirely. The stuff is hard to work with and basically causes cancer (yes you need to use a respirator). Also PVA is a very thin coat, so "blemishes" in your foam are going to show up more so use a caulk or a flexible modeling paste to patch up any cracks or smooth out any glue bumps and such before hand.

 

[BuildsByBaz]

...And make sure that any piece you wish to use filler on is an area that will not flex much.

the other thing is the flexiblity of wood glue... how thick was your layer? in my video i painted 2-3 layers and let them dry complet. the layer was about a half milimeter thin and its totally flexible. what exactly cracks? the wood glue layer or the paint above?
if only the paint cracks then you use a diffrent kind of spraypaints. acrylic and nitrogen paints are flexibile enough to resists the bending of the armor. take a look at the end of my linked video.

The part of the waist on my Iron Man suit is the sides between the lumbar and abdominal armour. My whole suit is fibreglass/rondo but this piece has to be flexible. So yes, It needs to flex. So far the single layer of undiluted clear wood glue has dried hard and cracks when bent.

 

[ferret304]

Thanks so much guys. I think I'll give the PVA a go... My WIP thread will be up soon so we'll see how that goes

 

[Hyperballistik]

I never have tried this personally but I have heard that latex paint (house Paint) will seal the foam and still remain flexible, if you have some around your home its worth a try to test it out on some scrap eva foam, someday in going to try it out myself

 

[Carpathia]

wooop woop woopp....
first of all... no epoxy resin or other resin as a sealing method... this doesnt work. its to hard and will no longer be flexible or its cracks at the right moment you tries to bend it.

I'm going to have to go ahead and correct myself, Harican. I've been using Envirotex Lite for years, and recently started testing it out on foam. When it cures, it's still flexible and does not crack, even when painted. The only thing negative it does is buckle a bit when bent inward on itself. Envirotext is a polymer compound that's primary purpose is bar-top finishes. Here is a link to the product...

https://www.google.com/shopping/pro...a=X&ei=tHtJUujBCuK02gXtoYDoDA&ved=0CFUQ8wIwAA

I've got a video that I have not organized yet showing how well this stuff performs. Now, as I mentioned, I'm not sure what's available in Australia (or Germany), so this may not be an option.

 

[Revenant1988]

I'd like to chime in with a question of my own since you guys brought it up.

For those of you coating your foam in PVA only, are you directly painting on top of that after it cures? Are any of you using spray paint when you do this? What are the results? It's my understanding that if you spray paint the PVA surface the PVA will react to the moisture of the spray paint and blemish- is this not the case?

Great thread btw!

 

[elusch99]

Harican, the Mod-podge doesn't need to be waterproof, it's for sealing the foam. You paint over it, so it doesn't matter. And it actually is waterproof, though not amazingly so. I personally use This stuff to waterproof, it works really well.

 

[ferret304]

I'd like to chime in with a question of my own since you guys brought it up.

For those of you coating your foam in PVA only, are you directly painting on top of that after it cures? Are any of you using spray paint when you do this? What are the results? It's my understanding that if you spray paint the PVA surface the PVA will react to the moisture of the spray paint and blemish- is this not the case?

Great thread btw!

As far as I know, it shouldn't react unless the PVA isn't dry. I've spraypainted over PVA before (never on armour though) and I've never had issues with it

 

[harican89]

So far the single layer of undiluted clear wood glue has dried hard and cracks when bent.

it have to be white wood glue. was the glue you used clear at the start?
white wood glue becomes clear when it dries but its normal color is white. these kind of wood glues contains the basic PVA. it should mentioned on the back of the glue bottle or on the producers webpage. google for the same of the glue and the keyword "PVA" or "Polyvinyl acetate"