Automotive paint fuel resistant?
Michael McEvilley
David M. Toddington wrote:
>
> I'm building Pacific Aeromodels Sukhoi ARF, I want to repaint the kit
> however and am wondering if anyone has any experience with model fuel on
> finished automotive paint... should I be painting the aircraft with
> something else?
>
I've used automotive acrylic enamel and acrylic urethane - neither was affected by
model fuel.
-michael
CAD RESELR
Dave: I ran a test with Duracryl Laquer. Put filler, primer, and Red
Duracryl on a piece of balsa (sprayed all coats except filler). Put a
small pool of 25% nitro fuel on it for 15 minutes (after it had cured for
about 4 days). After fuel was removed, saw only the slightest etching of
the surface. However, when I painted to plane, I think I mixed in too
much Flexall - paint never seemed to dry completely. Hope this helps.
Bruce.
Bjorn Lehnardt
>David Toddington wrote
>I'm building Pacific Aeromodels Sukhoi ARF, I want to >repaint the kit
>however and am wondering if anyone has any experience >with model fuel on
>finished automotive paint... should I be painting the >aircraft with
>something else?
Dave, I've wasted a good bit of money on many kinds of paint, so I hope I
can save you some trouble. Nitro in the fuel is the biggest problem. The
more nitro you use, the more resistant your paint needs to be. Basically,
with automotive paint, stick with POLYURETHANE. Most pattern builers use
this if not using epoxy paint. Lacquer is usless. Enamel (even with
catalyst) is unsuitable even for low nitro fuel. I have tried to protect
enamel with clear epoxy, (K&B or Hobbypoxy) or polyurethane, but
normal nicks and scatches eventually let nitro contact the enamel, which
softens and ruins it. I have used poly U with up to 40% nitro with no
problem. Pylon racers could probably tell us about higher percentages!
You MUST let the poly U cure properly. These are catalized paints that
need time to cure. Cure the paint inside the house, not
your freezing Canadian garage. My paint (PPG) needs at least two weeks.
Epoxy paint,(K&B - Hobbypoxy), are great too and cure faster. However
they are hard to match colors with Monokote, Ultracote, etc. MAYBE SOMEONE
WITH GOOD RECIPES FOR MATCHING EPOXY TO BASIC SHINK FILM COLORS COULD POST
HERE! You can also paint poly u over epoxy and vice versa. Just let each
cure first.
Most paint shops won't mix less than a pint, (is Canada metric?), and
charge a bit extra for custom color matches. Iron a patch of Monocote on
some scrap and they can match it. Mixed with the catalyst and reducer, a
few pints of differnt colors can really strech out for two or three planes.
Poly U and epoxy are not cheap so start saveing. If you spray like me, use
ultra fine sandpaper and polishing compound to straighten things out. Great
for your car too!
One more thing in this long winded thing. Make sure to use a good
CHARCOAL filter paint mask. (NOT a sheetrockers dust filter). You can get it
at the paint shop along with the paint. Something like "Imron"
or other poly u or epoxy can really mess you up. The filters are
replaceable,and the mask itself will last you your whole (unbraindamaged)
life.
I'm sure others have good solutions, maybe cheaper too. POST
and let us all know!
John Kenna
Enamels and Laquer are not fuel proof but can be used if clear coated (I
use DelClear, a PPG product). I have used Acrylic Enamel and Urithanes (I
have some Acrylic Urithane but have not used it yet), both are fuel proof
to 30% nitro (I have not used higher nitros, so I don't know if they will
take it).
Acrylic Enamel is very hard so it can crack when put on fiberglass, but
I have not had that problem. It needs to be given 24 hrs before masking
over it, so doing complicated patterns with lots of colors can be very
time consuming. Urithanes (including DelClear) are the same, they take
even longer to dry. The acrylic urithanes are supposed to dry faster (4
hrs). Laquer is the fastest drying (15 minutes), enamel is also fast (30
minutes).
All of these paints should be used with lots of ventalation and a paint
resperator. Also you should use rubber gloves for handling. You will also
have color matching problems. Several people are selling monokote
matching paints (I buy from Radio South).
Hope this info helps,
John Kenna
Mobile, AL