The article explains how to use brake fluid to
strip paint from hard (ABS) shells. Please be
warned that this technique does not apply to polycarbonate
Sometimes if you want to re-paint a model it's
acceptable to simply wet sand the existing paint
and apply a new top coat, but in many cases this
is not the best way as the thickness of paint
can make the shell lose detail. The existing paint
may also not be good enough even as a foundation
or might react with your lovely new paint. For
these reasons it's generally best when you can
to strip shells of all their paint giving you
an effectively new shell to work with. This article
explains how to do this using car brake fluid.
For this job I recommend the following equipment:
- Large crate/tub with lid
- Dot 4 brake fluid (8 litres or more)
- Wooden toothpick or wooden scewer
- 1000 grit wet and dry paper
- Rubber gloves
For most shells you will need around 8 litres
of fluid to allow a shell to be completely submerged.
A suitable plastic container is also required.
Stacking storage crates are pretty good for this,
a lid is a good idea to avoid splashes or anything
dropping into the fluid. If you can find a slightly
larger crate this can work as a good lid.
The brake fluid itself needs to be as cheap and
nasty as possible. Modern higher grade semi-synthetic
brake fluids of higher than Dot 4 are not as good
as they contain chemical corrosion inhibiters
to prevent damage to the brake components on the
car. We are actually looking for the corrosive
properties so go for the cheap Dot 4 fluid it'll
Please remember to always wear rubber gloves
when you're handling this stuff, it's pretty nasty
and should be washed immediately from your skin
if it comes into contact with it. Seriously, do
it in the garage or shed and nobody needs to see
you wearing those pink or yellow Marigolds!
To get started simply strip your shell of all
it's ancillary components and decals and submerge
in the fluid. We're starting here with a Blazer
shell that needs some TLC.
The first time you do this is quite scary, especially
if it's a valuable and vintage shell, but don't
worry the brake fluid is not corrosive enough
to damage plastic. If it was it would have come
through the container it came in or the crate
you are using remember?
Bear in mind that the rate of reaction here is
dependent on the temperature, if your crate is
in a cold shed or garage it will take longer for
the magic to happen. The warmer the place you
can do this the better. It may take some time
though so find somewhere that is out of the way.
All you have to do now is wait and keep an eye
on things. I've had paint come off in under 24
hours but that's unusual. Expect to wait a few
days before you see the paint starting to blister
Once this is happening it's worth working the
brake fluid into the paint with a toothbrush.
This will remove loose blistered paint and work
the fluid into the remaining paint.
If the paint is in multiple layers you may need
to repeat this process a number of times until
you are seeing bare plastic. If the shell is not
completely submerged it's best to "baste"
the shell with fluid using a pouring jug as often
as possible. Of course you can always turn it
over in the fluid from time to time.
If you check progress after a few days and nothing
appears to be happening leave it a while as I
have had some take up to a month before a reaction
is taking place. It just depends on the brake
fluid and the paint that's been used, some react
more than others. Some of course don't react at
all which is where more drastic action can be
taken (watch out for future articles). This method
is a model safe way of doing things and in my
experience has worked with probably 80% of shells
I have tried it on.
Of course you can use this technique on other
things that have been painted such as wheels,
drivers and other body parts. I haven't tried
it on anything chrome that's been painted so i
can't be sure it wouldn't affect the chrome plating.
Well it's just a job of removing all the paint.
On smooth a simple shells such as a Sand Rover
you can expect most of the paint to come off in
the brake fluid but it most cases the paint will
cling in the details lines and corners of the
shell. To remove these I use a toothbrush and/or
a wooden scewer.
This can take some time but it's worth doing it
properly, if you leave paint in the details of
the shell it will show when you paint it and I'm
sure you don't want to have to strip it again?
Finally it's time to clean the shell ready for
paint. To do this scrub the shell in hot water
with washing detergent in it,
at this stage you might wish to key the shell
with fine wet and dry paper
giving it a rough finish for paint to stick to,
and remove any last traces of paint on the shell
again using a wooden screw or toothpick. You may
find that the shell is stained from the paint
used, this is quite normal and there is not much
that can be done, you can wet sand some of it
out but this isn't necessary as you'll be re-painting
Finally just rinse the shell in clean water and
leave to dry ready for new paint!