Painting flexible rubber parts

Arsenic Hipster · Post by **Arsenic Hipster** » Sat Mar 03, 2007 6:56 am

I'm sure this have been covered before somewhere but I can't seem to find anything other than on vinyl figures which consists of fill the model to prevent movement and use the right primer.

What I'm talking about is painting flexible rubber parts which can't be filled and may or may not end up being flexed.

First I've just finished putting together a Hasegawa 1/72 Tiger tank and the treads for this kit are made from two strips of black rubber. You join the ends to make a loop and fit that around the road wheels and gears of the tank. Is it even possible to paint something like this and still have some paint left on once they are fitted to the model? I expect that movement of the rubber will be only a small amount of flexing when it is lifted off or placed on a shelf. Has anyone had a similar problem, what sort of paint did you use to do it?

I've also got a couple of Patlabor models that use rubber parts to cover the joints in the arms, legs and waist. In both the 1/60 kits and the MG ones the rubber is coloured to be sort of like what is needed in the finished model. The finished models have some pose ability and the rubber will no doubt be flexed on from time to time. For these I was thinking that an ink wash would pick out the recesses and wrinkles moulded into them and then and not flake off like paint. Other than that maybe vinyl dye, I've heard of people using it on things like computer cases since it soaks into the plastic and won't scratch off. First a coat that is wiped down to only leave dye in the recessed bits and once its dry follow up with a light coat across the entire piece to smooth out/blend the colour.

Has anyone tried this before and did it have much success? If not what did you do instead? Is a particular brand or type of paint best suited for this type of thing.

intergalacticthingamejig · Mon Jul 16, 2007 11:35 am

Don't know if this is of any help? However, years ago i used to be into racing RC cars, we had to paint our body shells with either Pactra or Tamiya paints (A different range of paints designed for lexan bodies), the paints have a different formula and when dry have flexing properties.

Wayne

SpaceDuck · Post by **SpaceDuck** » Mon Jul 16, 2007 12:12 pm

"A.H.",
I also model 1/72 AFVs and know those tracks. Fisrt, enamel doesn't seem to want to cure on that soft of vinyl, it stays kinda gummy? Lacquer will dry but is notoriously stiff so not a good choice. Good ole acrylics (I happened to use Citadel colors) go on and actually survive assembly and handling.
Maybe others who work the vinyl mecha genre can speak better for that application? I've also used Pactra RC paints and they'll hold up well on things like derlin model railroad railings and such but rely on a "shell" for integrity. Namely the whole piece should be covered on all facets and then it sticks and stays to flexible parts, to a point at least?

Good Luck

Floyd Walker · Post by **Floyd Walker** » Tue Jul 17, 2007 7:23 am

Something to watch out for as well-
Some types of vinyl/rubber used for those tracks (and potentially on other parts as well) does not react well to certain types of paint.
By this, I mean that they will possibly disintigrate within a month or two

. And no, I'm not exaggerating.
It's usually associated with solvent-based paints, as well as the gluable types of tracks.
Searching the forums on Armorama http://www.armorama.com/ can give you a good idea on what works well with what.
In a nutshell- acrylics are generally safe, enamels less so, laquers... probably should avoid. (From what I've read, so YMMV)

Dr. Yo · Post by **Dr. Yo** » Tue Jul 17, 2007 11:02 am

One caution on the Patlabor kits-the rubber used for the sleeves will
attack the styrene of the kit-to the point of melting it. I found this out
after pulling the Brocken* out of storage awhile back. the pins for the
knee and hip joints were almost completely disintegrated, and the
rims of the hips looked like they'd been left stting in a puddle of tube
cement for a week...Sealing the model completely with paint may prevent
the worst of it, but I know a lot of folks had this problem with the
Patlabor kits. Just FYI.

* that I had built but not painted many years
ago

Post by **TER-OR** » Tue Jul 17, 2007 6:33 pm

Weathering with oils is a good idea on these.

SpaceDuck · Post by **SpaceDuck** » Tue Jul 17, 2007 10:48 pm

An FYI if ever you find it applicable:

Automotive paint suppliers have 'flex agent' additives that can be mixed into your paint. You can vary how much flexibility you want in the paint but I should caution it does slightly change the 'tint' of your color. It was developed for, TADA- flexible car parts that need to be painted! The reason I bring it up is in case you are trying to retain a particular finish/color being used on standard parts that intersect, border or continue through a flex area*. Maybe you've chosen a nice mettalic lacquer with pearl overlay and that's just not available in oils, acrylics or whatever else- just use the additive. But it comes in quantities considered large and therefore, expensive, for our hobby? But hey, one can and you'll have enough for as many models as you'll probably build in a lifetime!

*By the same token you could just use the agent in all of your paint and avoid the color tint issue but we never chose that option on full size cars/trucks.