John-
Could you bring some of this stuff, such as your home-made buffer, to Rough
River and demo it?=C2- I think we could all learn a few things.
Jim Puglise
----- Original Message -----
From: TELEDYNMCS@aol.com
Sent: Thursday, July 9, 2009 9:15:21 AM GMT -05:00 US/Canada Eastern
Subject: Europa-List: Re: Bubbling paint
In a message dated 7/9/2009 3:02:51 A.M. Eastern Daylight Time, europa-list
@matronics.com writes:
>>>>>Cars and store bought airplanes are metal, blistering is a composites
problem. If there are any fingerprints, unreacted resins, whatever, on
the surface before painting osmosis will occur. ALL paint systems are
permeable. As you say, wax is best<<<<<
Hey Graham,
Yes, a lot of them are metal, but blistering can occur on metal airplanes,
too. My father owned a Mooney back when I was a teenager. The airplane was
less than 2 years old and developed blisters on both wings. He sent it back
to the factory in Texas to have it fixed=C2-and unfortunately, it was de
stroyed in a hail storm. Although that airplane sat out in the weather cons
tantly the blistering probably had little to do with rain and everything to
do with paint preparation. Gel coat is bad about blistering on boats that
are in the water constantly. I've owned a couple of sail boats that were do
cked permanently in water and both developed blisters on the hull below the
waterline=C2-after a while in the water.
>>>>>I always wanted to use a polish for extra protection=2C but I am afr
aid tha
t it would be very difficult to do any future touchups. My experience with
furniture lacquers is=2C that it is very difficult to re-finish a tableto
p
where any polish was used containing wax or silicone=2C even when it is s
tr
ipped down to the bare wood.<<<<<<
Hey Karl,
The one thing you want to avoid at all costs is any finish enhancer that co
ntains silicone. That goes for DOT 5 brake fluid, too.=C2-Silicone is ext
remely hard to get off once it's on the finish. Even sanding thoroughly won
't get it all off. There are silicone removers available. Most major paint
manufacturers make them in one form or another. We've tried a variety of=C2
-them with mixed results. Repeated wiping with acetone in between sanding
seems to work best, but we still get paint rejection from time to time. It
's a real bitch sometimes and requires several cycles of painting and sandi
ng to get=C2-the paint=C2-to stick if silicone is present. We've never
had problems with bubbling or paint rejection=C2-after we got the paint o
r gel coat=C2-to stick, though.
>>>>>>Your experience seems to indicate that this is not a problem with gli
der an
d Europa finishes. Can you confirm that and let us know what you use to pre
pare the surface for re-painting ? I never used carnuba wax. Is it availabl
e in car shops=2C and do I need a powered polisher for application ? Whic
h
polishes are to be avoided ?<<<<<<
Carnuba wax is a high quality car wax and it seems to produce the best resu
lts. We use it on both urethane and=C2-gel coat finishes.=C2-Wx Block i
s also good, but it's pricey. Some folks prefer wax, others like Wx Block.
Personally, I like wax better because it shines better.=C2-You can usuall
y find a good=C2-Carnuba wax=C2-at any decent auto parts store. Expect
to pay around $10-$12 a tin for it. We use the paste type Carnuba. Carnuba
also will wipe off with acetone and/or sanding.=C2-
We tell folks to avoid anything with silicone, sillica or similar ingredien
ts, though. Use of such products will be troublesome later on if you need t
o do a repair. As I previously mentioned this is why we do not recommend fu
rniture polishes for canopies, but rather plexiglass wax. Canopy rails are
usually the first place paint or gel coat will chip because they flex and t
here are different expansion and contraction rates for the fiberglass rail
and the plexiglass canopy. This usually causes a crack to form at the edge
where the two meet. Chips usually follow.=C2-=C2-Silicone products, eve
n though they are slippery, also seem to=C2-tend to hold a slight electri
c charge which tends to cause dust to stick to the surface. We saw that one
play out a couple of years ago at a glider meet out=C2-in Uvalde, TX. Th
ere was one guy in the field of competitors=C2-who wiped his whole glider
down every day with furniture polish. Uvalde is desert conditions and ther
e is a lot of dust.=C2-By the end of the meet his glider was a dust magne
t. No one else at the meet was having the problem.
The wax is applied by hand, but you don't necessarily have to use a buffer
once it's ready to wipe out, but it does help melt the wax and gain a bette
r application and a much better shine. I would not use an orbiting type buf
fer, though. Those type=C2-buffers will=C2-create swirls in your paint.
We build our own buffers out of a variable speed=C2-7" die grinder. We
=C2-use 9" flannel buffing pads stacked up about 5" thick. You can get "t
hreaded collars" to fit the arbor of the grinder=C2-at virtually any hard
ware store to lengthen the grinder arbor=C2-shaft by about 3". First, put
on a big fender washer, then the collar.=C2-Then, we add about 5" thick
of 9" flannel buffing=C2-pads to the shaft.=C2-We really pack the pads
on the shaft and sometimes it=C2-involves using a hammer to beat them ont
o the shaft so they are good and=C2-tight.=C2-Then,=C2-another big fe
nder washer and a bolt that mates to the other end of the threaded collar.
Buffing is done end on. This way it does not create swirls, only shine.
You have to pay particular attention when you are buffing control surfaces
and near leading and trailing edges. It's best to buff those parallel to th
e wing or control surface for safety. If you buff=C2-90 degrees to the co
ntrol surface=C2-or wing edge and=C2-aren't very careful it's easy to c
atch on the edge of a wing or=C2-control surface like an aileron or eleva
tor if you don't pay attention to the direction of rotation=C2-and you ca
n damage the surface. I also "bump" the trigger repeatedly so that the buff
er doesn't get going too fast when I'm near the edge. Some=C2-grinders sp
in too fast for buffing, so we use a router speed control to provide better
control the=C2-RPM.
=C2-When buffing near the edge make sure the direction of rotation is out
ward=C2-from the surface's edge. If the rotation is inward toward the edg
e you risk the buffer grabbing. I've twice seen ailerons literally=C2-tor
n off by folks who weren't paying attention. You don't have to put much pre
ssure on the buffer, either. Usually, it's own weight is enough to do the j
ob. It will give your forearms a good workout, though. I can send you some
pictures of the buffers we use if you'd like.
Hope it helps!
Regards,
John Lawton
Whitwell, TN (TN89)
N245E=C2-- Flying
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