Poly-Props SEAL Brush On and how to use it

Update: 23/10/2018

Poly-props has since released something called Hexflex. I would recommend applying 3 layers of this before this so it won't get absorbed into the foam as much hence saving even more money.

After my initial thoughts of the SEAL here, Poly-props has released the much cheaper brush on version. I will be going through my final thoughts here as well as how to use it.

TL;DR like plastidip but without the shitty rubber texture. Other people has bought it off my recommendation but havehad varied results; some good, some awful.

It has the same properties of the spray on stuff (flexible and primer like texture) but it is much much cheaper. It comes in 500ml or 1L tins. To give you a quick idea how long a tin last, a 1L tin covered a full armour build (shovel knight) just a little over 2.5 times.

The brush on version is a little tricky to apply but if you're like me and want to save money on the expense of time, the brush on is pretty good.

  • -Fairly cheap
  • -Dries quicker than PVA
  • -Flexible
  • -Primer like texture so you don’t have to purchase primer to go on top of it
  • -Takes as long to apply as PVA
  • -The tin will last a long time
  • -Easy to apply – at least I found it that way!
  • -You must work in a well ventilated area (I got really high when I did it in my greenhouse).
  • -It smells pretty bad and will stink out the entire room you're working in and more.
  • -Won’t work as well in direct sunlight
  • -Could be difficult to get the mixture right and end up with unexpected results

Application and Tips

These are NOT how it should be used, it’s techniques I’ve discovered to make the application much smoother.

I have had a few people complain that the brush on came out lumpy and unsmooth. I’ve only had that problem the first time I’ve used it straight out of the tin because it was too thick. I’ve included some examples below of what it would look like when you apply layers that are too thick.


First of all, don’t be an idiot and leave the tin opened for days. This stuff, like most other liquid sealants, it dries when you let it air. There has been stories where someone left the tin opened for days and it turned out solid. Get some half pint cups to pour the SEAL in when you’re working with it. A little bit goes a long way; with 1/4 pint worth + some white spirit, it was enough to cover my gun 3 times with another layer’s worth to spare.


Since the product is so thick, you will need to dilute the SEAL with some white spirit/other paint thinners. The ratio I use really varies but the general guideline is about 1:4 or 1:3 depending on preferences (1 part white spirit, 4 part SEAL). For the duration of you applying the first layer to the second, the SEAL will start to dry slightly hence making the mixture thicker and returning to the original state. You will need to keep topping it up with little bits of white spirit to keep it with the same consistency.

Since the product is so quick drying, I would avoid applying it in direct sunlight. Find a spot of shade or something. I found that it tends to congeal and clump when I applied it on a very warm day.

To apply it, you could either use cheap poundland paint brushes or foam brushes. The SEAL should self level a little but obviously, try to minimise brush marks when you apply it in the first place. 

IMPORTANT NOTE: If you do choose to use a foam brush/sponge method, watch out for bubbles when applying the foam. You must get rid of them before it dries.

Don’t try to put everything on in one go. You’ll end up with a lumpy finish if it’s too thick. Three thin layers should do it. Here’s what I try to do for each layer:

Layer 1

Same as applying any sort of sealant (PVA, Plastidip etc), the first layer will also be soaked into the foam. You will need to keep dipping your brush lightly and apply it to the prop in small sections. Let it soak and stop trying to resist it by applying thicker layers.

Layer 2

Just build on top of the first layer. The foam may absorb parts of this layer as well.

Layer 3

The foam should have properly soaked into the foam to form sealant. It should be a lot easier and smoother to apply than the previous layers. One dip of the brush should cover a much larger surface area than the previous two layers. This layers is basically to get all the colours consistent and cover the whole prop.

Layer 4 and onwards

If layer 3 still hasn’t covered the whole thing thoroughly, apply an extra layer. 5-7 layers is perfect but you could probably get away with 3 if you're cheap and/or lazy