Refinishing questions

[[email protected]]

Hello ;)
I'm about to start refinishing a Discus.Searching through this and
other forums I've noticed people are leaning towards polyurethane and
away from gelcoat.Gelcoat seems to be much easier in my situation,
since I don't have a spray booth and they don't recommend sanding poly
after you've painted.I asked about PPG Concept locally and the dealer
says that acrylic urethanes shouldn't be sanded.Their top of the line
poly is called Deltron- but he couldn't say why it is better than
Concept.There's also DuPont with it's products- and they are 3-4 times
cheaper than PPG.I wonder if they really differ in quality that
much.Please advice.
Before the paint I'll have to fix one of the canopy hinges-
the rear one - it's delaminated and moves quite a bit.Pictures of the
crack are here http://picasaweb.google.com/barowicz/Canopy. How to fix
such a small detail? It seems that it takes a lot of stress and that's
why it's cracked.

Thanks,
LB

[Bill Daniels]

> wrote in message
...
> Hello ;)
> I'm about to start refinishing a Discus.Searching through this and
> other forums I've noticed people are leaning towards polyurethane and
> away from gelcoat.Gelcoat seems to be much easier in my situation,
> since I don't have a spray booth and they don't recommend sanding poly
> after you've painted.I asked about PPG Concept locally and the dealer
> says that acrylic urethanes shouldn't be sanded.Their top of the line
> poly is called Deltron- but he couldn't say why it is better than
> Concept.There's also DuPont with it's products- and they are 3-4 times
> cheaper than PPG.I wonder if they really differ in quality that
> much.Please advice.
> Before the paint I'll have to fix one of the canopy hinges-
> the rear one - it's delaminated and moves quite a bit.Pictures of the
> crack are here http://picasaweb.google.com/barowicz/Canopy. How to fix
> such a small detail? It seems that it takes a lot of stress and that's
> why it's cracked.
>
> Thanks,
> LB

I'm looking at the same thing you are. I've been studying the options for a
couple of years.
I've decided that gelcoat is the better option for me. Take a look at Jim
Phoenix's site where he refinishes a Nimbus 3. http://www.jimphoenix.com/

Polyurethanes are wonderful materials that are very durable and last a very
long time. In this regard, they are better than gelcoat. However,
everything depends on surface preparation and priming. You'd better get the
prep right 'cause it's hard to fix problems after you shoot the final coat.
To spray polyurethane, you really need a profesional spray booth with
professional skills and tools. It can be repaired but it's best not to.

OTOH, gelcoat is a more forgiving process - easily sprayed and highly
sandable. The refinish process is relatively simple. Just grind off the
old white stuff, fix dings, fill and contour the surface, spray gelcoat and
sand/polish to the desired finish.

Note that minor 'orange peel' and/or runs in a freshly sprayed gelcoat
surface aren't a big deal since you plan to sand off most of the coat
anyway. If you really screw up a spot, just repeat the process for that
area. Try some small projects like gear doors first so you climb the
learning curve on out-of-sight parts.

To do it right you need a clean shop with reasonably controlled temperature.
Keep in mind that a refinish can be considered a 'major repair' which
requires proper paperwork and AI sign offs. It's especially important to
keep control surface weight and balance within the limits specified in the
maintenance manual. A owner/pilot is allowed to do anything to his aircraft
that an AI is willing to sign off. Find a friendly AI before you start.

Bill Daniels

[[email protected]]

Bill, LB,

If I had to do it all over again, I'd use polyurethane. Gelcoat is
such a long process that I only got one wing, tail and part of the
fuselage done, but really it's the weight of the gelcoat that's so
discouraging. Poly-u is much lighter. Gary Kemp did his N3 in poly-u.
Definitely the way to go with all the usual cautions about spraying,
etc. Keep in mind gelcoat has it's own health problems with the
catalyst MEKP able to cause instant blindness. It's also expensive and
takes a while to get all the clever tricks learned.

Stripping and varnishing an old wooden boat seems so much easier ;-)

Jim

On Jan 6, 7:56 am, "Bill Daniels" <bildan@comcast-dot-net> wrote:

> I'm looking at the same thing you are. I've been studying the options for a
> couple of years.
> I've decided that gelcoat is the better option for me. Take a look at Jim
> Phoenix's site where he refinishes a Nimbus 3.http://www.jimphoenix.com/
>

[Tim Taylor]

On Jan 6, 9:13 am, wrote:
> Bill, LB,
>
> If I had to do it all over again, I'd use polyurethane. Gelcoat is
> such a long process that I only got one wing, tail and part of the
> fuselage done, but really it's the weight of the gelcoat that's so
> discouraging. Poly-u is much lighter. Gary Kemp did his N3 in poly-u.
> Definitely the way to go with all the usual cautions about spraying,
> etc. Keep in mind gelcoat has it's own health problems with the
> catalyst MEKP able to cause instant blindness. It's also expensive and
> takes a while to get all the clever tricks learned.
>
> Stripping and varnishing an old wooden boat seems so much easier ;-)
>
> Jim
>
> On Jan 6, 7:56 am, "Bill Daniels" <bildan@comcast-dot-net> wrote:
>
> > I'm looking at the same thing you are. I've been studying the options for a
> > couple of years.
> > I've decided that gelcoat is the better option for me. Take a look at Jim
> > Phoenix's site where he refinishes a Nimbus 3.http://www.jimphoenix.com/

I would second Jim's recommendation. I did the outer panels of my
Nimbus 2 a few years ago and I did it in PU. It is not that bad a
process. The nice thing is most body shops are set up to handle PU
paints. Do all the prep work yourself and then hire a local shop to
shoot the last coat of primer and paint. The work in PU is upfront,
it needs to be finished to final smoothness and shape before the
painting. The nice thing is once done you will likely never do it
again if you take care of the glider.

Search for sites that talk about finishing homebuilt aircraft like
Long-ez's, etc.

Find a good AI to work with from the start. Make sure you can do the
mass balance checks on control surfaces. I would recommended doing a
before and after as a check rather than just the after mass balance
weights.

[[email protected]]

Having done several of both, I do not see a clear answer for a
refinish.

One issue I do see clearly:

The root cause of essentially all the finish problems observed in
gelcoated gliders lies in the criminally substandard "modern"
materials used by most of the manufacturers.

There is abolutely NO reason the gelcoat finish on gliders should
fail. Gelcoated sailboats are subject to high humidity, salt water,
huge structural loads, and a lack of care by their owners yet do not
display the problems we see in our aircraft. Libelles that are 30
years old still have nearly perfect finishes. I have a gelcoated
camper shell on my pickup that has been essentially ignored and
outside for 17 years old and shows no sign of crazing or failure. I
know of several Grob products that have been out in the western USA
for 20+ years with little or no finish care and they have not
crazed.

If $100K gliders were Dodge pickups, there would be a class-action
suit filed against the manufacturers for shoddy materials.

Rant Off. Back On Topic.

"Gelcoat" Refinish (catalyzed polyester paint): Poly-Lux, Prestec,
Simtec, Vorgelat, Schwabellac (sp), Ferro, and many others

Pro's: Less skill and facilities required to apply and end up with a
good finish. Far less hazardous to work with. Easier to fix nicks
and dings. Can be profiled/contoured years after application.
Typically this can be done at least once and usually twice before
significant sand-through of the finish occurs. Less expensive than
PU

Con's: All things being equal it is not as durable as 2-pack PU,
especially if the ship is subject to environmental abuse (tied out
full-time) Requires more waxing/polishing. Subject to stress cracks
when applied thickly to floppy wings but this can be mitigated. Can
yellow with time.


2-Part Paint: PPG, Dupont, Glasurit, Imron, many others

Pro's: Very durable, shiny finish that can withstand the elements.
Does not yellow.

Con's: Very hazardous to apply (especially isocyanate catalyzed
types), Requires very good equipment, good facilities, and superior
skill to apply well. Very expensive paint systems (as much as $400
per gallon). More expensive and time-consuming to repair nicks and
dings, Cannot be profile/contour sanded after application without
repainting due to thin topcoat film thickness.

Someone mentioned that PU refinishes weight significantly less. That
has not been my experience. The PU topcoat is very thin but the
amount of primer-surfacer required to contour the surface and fill all
the pinholes in the fiberglass seem to negate any weight savings over
gelcoat. This is especially true when individuals have piled on the
primer and not sanded enough off and/or not removed all of the
previous finish.

Moisure (vapor) migration in and though epoxy composites can lift PU
topcoats due to their impermeability. Polyester coatings are porous
and allow migration.


For racing-class ships that will be taken care of, my vote is
"gelcoat".

[Papa3]

On Jan 6, 3:24*pm, " > wrote:
> Having done several of both, I do not see a clear answer for a
> refinish.
>
> One issue I do see clearly:
>
> The root cause of essentially all the finish problems observed in
> gelcoated gliders lies in the criminally substandard "modern"
> materials used by most of the manufacturers.
>
> *There is abolutely NO reason the gelcoat finish on gliders should
> fail. *Gelcoated sailboats are subject to high humidity, salt water,
> huge structural loads, and a lack of care by their owners yet do not
> display the problems we see in our aircraft. Libelles that are 30
> years old still have nearly perfect finishes. I have a gelcoated
> camper shell on my pickup that has been essentially ignored and
> outside for 17 years old and shows no sign of crazing or failure. *I
> know of several Grob products that have been out in the western USA
> for 20+ years with little or no finish care and they have not
> crazed.
>
> If $100K gliders were Dodge pickups, there would be a class-action
> suit filed against the manufacturers for shoddy materials.
>
> Rant Off. *Back On Topic.
>
> "Gelcoat" Refinish (catalyzed polyester paint): *Poly-Lux, Prestec,
> Simtec, Vorgelat, Schwabellac (sp), Ferro, and many others
>
> Pro's: Less skill and facilities required to apply and end up with a
> good finish. *Far less hazardous to work with. *Easier to fix nicks
> and dings. *Can be profiled/contoured years after application.
> Typically this can be done at least once and usually twice before
> significant sand-through of the finish occurs. Less expensive than
> PU
>
> Con's: *All things being equal it is not as durable as 2-pack PU,
> especially if the ship is subject to environmental abuse (tied out
> full-time) *Requires more waxing/polishing. Subject to stress cracks
> when applied thickly to floppy wings but this can be mitigated. Can
> yellow with time.
>
> 2-Part Paint: *PPG, Dupont, Glasurit, Imron, many others
>
> Pro's: *Very durable, shiny finish that can withstand the elements.
> Does not yellow.
>
> Con's: *Very hazardous to apply (especially isocyanate catalyzed
> types), Requires very good equipment, good facilities, and superior
> skill to apply well. *Very expensive paint systems (as much as $400
> per gallon). *More expensive and time-consuming to repair nicks and
> dings, *Cannot be profile/contour sanded after application without
> repainting due to thin topcoat film thickness.
>
> Someone mentioned that PU refinishes weight significantly less. *That
> has not been my experience. *The PU topcoat is very thin but the
> amount of primer-surfacer required to contour the surface and fill all
> the pinholes in the fiberglass seem to negate any weight savings over
> gelcoat. This is especially true when individuals have piled on the
> primer and not sanded enough off and/or not removed all of the
> previous finish.
>
> Moisure (vapor) migration in and though epoxy composites can lift PU
> topcoats due to their impermeability. *Polyester coatings are porous
> and allow migration.
>
> For racing-class ships that will be taken care of, my vote is
> "gelcoat".

Hey Mark,

Very thoughtful post. Quick question for you. Assuming you used
Simtec (Prestec) gelcoat, do you remember which of their formulations
you used? We (meaning glider pilots who are stupid enough to fiddle
with this stuff) seem to use the 2381 formulation, but their
literature suggests they have a formulation with additives designed to
make the finished product more flexible. Just curious whether anyone
has experimented with the various flavors of the polyester-based
products.

Thanks,

P3

[[email protected]]

I have used Simtec/Prestec 2381 and Poly-Lux which I believe are
essentially the same. Simtec will add flex agent to any of these and
to their primer-surfacer, I believe. In recent years, I have always
had the flex agent added but I have no data on its efficacy over long
periods of time nor have I done a total refinish with it - and hope to
never again. As JJ has said repeatedly, it is brutal, messy, bad-for-
you work and barely worth what one gets paid to do such labor. I know
several pilots who stripped and/or refinished their own ships. The
next time they needed such work, they got out their checkbook.

A colleague has used the Ferro (spelling?) product and is quite happy
with it. He also mixes several different brands to meet his viscosity
needs.

Real-time experimentation is tough to come by. No one I know is
willing to gamble this much money and work. They tend to stick to
known, materials, understandably.

My observations suggest that the critical factors in making a finish
last are: 1) Keep the thing dry, clean, waxed and buffed. Crazing is
a shrinkage phenomena. Keep the finish "hydrated" (not water) and
it will not shrink. 2) Keep the finish thin and definitely within the
paint manufacturer's tolerances . Thick coatings tend to mechanically
crack far more than thinner ones and craze as the trapped solvents
evaporate. This is true with both polyester and PU coatings and their
primer/surfacers. The latter phenomena has come back to haunt me
in the past and is a very, very common problem in the refinished ships
I have seen. Not only is the finish more likely to crack/craze, it
makes for a heavy glider.

[[email protected]]

Assuming this is a Schempp-Hirth, you can buy new hinges. They are
screwed/bonded in and can be replaced. I have fixed several of these
in situ as well with glass and epoxy-based adhesives.

That hinge design is a major weakness that is possibly intentional so
the canopy will break away if you get the jettison sequence wrong. At
least one pilot has been beaten about the head and shoulders by a S-H
canopy that did not go away when he wanted it to.

[[email protected]]

Getting a "Pro" to shoot the last stages of a PU refinish is an
excellent idea BUT be 100% sure your "Pro" has experience painting
large objects. Most bodyshops paint small objects like quarter panels
and hoods. Painting something as large as a wing or as convoluted as
a fuselage is a whole different animal. Keeping a "wet edge" to the
paint is an art on such objects.

How do I know? We contracted out an AS-K21 wing Imron (isocyanate
catalyzed) paint job to the local high quality body guy with his world-
class spray booth and equipment and got back a finish that we had to
sand completely off and redo. I shot it the second time with
inadequate breathing gear and got a great finish and felt like crap
for 2 weeks.

Ah, the good old days!

[[email protected]]

Hello,

MG wrote:
> class spray booth and equipment and got back a finish that we had to
> sand completely off and redo. I shot it the second time with

The shop I was surveying the other day uses Sherwin-Williams urethane,
they have all bells and whistles, but when I asked about how they're
planning on doing a fiberglass ship
the manager said that they'll "shoot it and then put it into the oven
for some time to cure" just like
it was a truck ;)
According to Randy Lervold http://www.romeolima.com/RV8/Paint.htm you
can shoot PU with a bit
of preparation.There is a certain amount of preparation needed but as
far as I remember, gelcoat or
any other paintjob needs good preparation.The only thing I don't like
with gelcoat is that it cracks;
however-will it really crack so bad on a refinished 20 year old glider
as on the new one if you keep it
in the trailer? In other words: how many of these cracks are stress-
imposed and how many by the resins being cured?
(and shrinking/warping of the parts)

I wish I could fix the hinge somehow, but I'm glad to hear that
they're replaceable.

Thanks,
LB

[RL]

Just to be technically accurate - Simtec or Prestec are not gel
coats... they are polyester topcoats. Gel coat is formulated as an in-
mold coating, but can be used as a post-mold coating with the addition
of a "air-dry" additive. Linear polyurethane (i.e., two-part mixture)
is a coating formulated for finished spray application. Simtec is
essentially a polyester-based finish coating designed for application
similar to a polyurethane paint, except using polyester chemistry.

So we have:

Gel Coat - Designed as an in-mold coating, but can be modified for
application as a spray finish. Requires significant finish sanding and
polishing.
Topcoats - Designed as a finish coating - Can be urethane or polyester
chemistry. Depending on quality of spray application, finishing can
range from no sanding/polishing to minimal post-finishing required.

Hope this helps.

Bob

[[email protected]]

I finished a Silent 2 Targa kit this past fall and used the Loehle
Aero Coatings which is a two-part poly formulated for aircraft. To be
sure, there is a tremendous amount of work involved in achieving a
good finish, but the Loehle covering process worked as advertised. I
did use a pricey HVLP spray system that pumped fresh air along with
air for the gun, in deference to the toxicity of this type of
covering. The point of my response here is to say that I did both
sand and polish the two-part poly, to an excellent shine. It was hard
work, but the results are quite satisfying. I'm happy to send a photo
and correspond with anyone who is contemplating using this product.
(I'm not on commission!)

Mike Hostage
Norfolk, VA

[Udo]

I would like to second the comments below.
Having experience with 3 projects, the last one I did in PU. The
results were out standing, even though the spraying was done in a home
made spray both , 11ft x 34ft with a 1HP exhaust fan and fresh
filtered air coming into the spray both. The unsanded final finished
would have been ok too. But the miniscule orange peel effect is just
not exceptable to glider pilot, hence it was sanded and polished too
a nice finished.

The PU I used is the same that is used an all Bombardier Jets.
The sanding primer that goes along with it allow for very easy and
controlled sanding without plugging the sanding pad. I also used the
primer in a squeegee process on the wing. Only when I was happy with
the accuracy of the surface did I spray on the first primer coat,
sanded it and spray a second one and sanded it as well with dye, to
control the sanding process. I also sanded the finished product with a
dye as a guide.

I also had good experience with the Polyester Product.
If you go that route, use a very good tooling gel and mix it with
20%-25% Dura Tech, it transforms the gel coat into a paint like
product.
Most importantly it prevent cracking and protects it from the sun.
I finished 2 gliders like that, they are still flying with all there
glory after 15 years, one was a St.Cirrus. The second one, only has
about 12 years on it. The gel coat is heavier, it needs to be, as it
does not hide as well.
Udo


On Jan 8, 2:11*pm, wrote:
> I finished a Silent 2 Targa kit this past fall and used the Loehle
> Aero Coatings which is a two-part poly formulated for aircraft. *To be
> sure, there is a tremendous amount of work involved in achieving a
> good finish, but the Loehle covering process worked as advertised. *I
> did use a pricey HVLP spray system that pumped fresh air along with
> air for the gun, in deference to the toxicity of this type of
> covering. *The point of my response here is to say that I did both
> sand and polish the two-part poly, to an excellent shine. *It was hard
> work, but the results are quite satisfying. *I'm happy to send a photo
> and correspond with anyone who is contemplating using this product.
> (I'm not on commission!)
>
> Mike Hostage
> Norfolk, VA

[JJ Sinclair]

On Jan 8, 11:11*am, wrote:
> I finished a Silent 2 Targa kit this past fall and used the Loehle
> Aero Coatings which is a two-part poly formulated for aircraft. *To be
> sure, there is a tremendous amount of work involved in achieving a
> good finish, but the Loehle covering process worked as advertised. *I
> did use a pricey HVLP spray system that pumped fresh air along with
> air for the gun, in deference to the toxicity of this type of
> covering. *The point of my response here is to say that I did both
> sand and polish the two-part poly, to an excellent shine. *It was hard
> work, but the results are quite satisfying. *I'm happy to send a photo
> and correspond with anyone who is contemplating using this product.
> (I'm not on commission!)
>
> Mike Hostage
> Norfolk, VA

Good point, Mike........one can sand and polish PU and AU as long as
enough paint is applied. The auto painters spray on one medium coat
and one flow coat and never want to touch it again. Glider shops spray
on four flow coats and sand off some of the last coat with 600W and
800W (even finer if your a fanatic) then buff it out with liquid
rubbing compound. The PIK came with sanded PU and the Genesis came
with sanded AU. One doesn't need to worry about over-spray or keeping
a the wet-edge, if your going to sand it later. I often spray one side
of a wing, let it dry, turn it over and spray the other side after
touching the blend area with 220D. I also have found a good PE "white"
primer that goes on smooth and doesn't ball up like that damned Simtec
2081.
JJ

[Brian Bange]

>
>Good point, Mike........one can sand and polish PU
>and AU as long as
>enough paint is applied. The auto painters spray on
>one medium coat
>and one flow coat and never want to touch it again.
>Glider shops spray
>on four flow coats and sand off some of the last coat
>with 600W and
>800W (even finer if your a fanatic) then buff it out
>with liquid
>rubbing compound. The PIK came with sanded PU and the
>Genesis came
>with sanded AU. One doesn't need to worry about over-spray
>or keeping
>a the wet-edge, if your going to sand it later. I often
>spray one side
>of a wing, let it dry, turn it over and spray the other
>side after
>touching the blend area with 220D. I also have found
>a good PE 'white'
>primer that goes on smooth and doesn't ball up like
>that damned Simtec
>2081.
>JJ
>
When I repainted my ship in PU, I found a product at
the paint store from 3M called 'Guide Coat'. It is
a black powder that comes with a foam pad applicator.
You smear this on the painted surface, wet it down
with water and go at it with 600 - 800 sand paper on
a sanding pad. The Guide Coat shows the valleys between
the orange peel. When it is gone, the surface is smooth.
This stuff works so well and is so easy to apply that
I can highly recommend it to anyone who is trying to
finish sand their ship. I went back and reapplied the
guide coat between the 600 and 800 and it showed the
scratches, so it was also a good indicator of when
to stop with the 800 grit.
I was told to put extra paint on all the edges, which
I did. I still sanded through in spots. You really
have to hit any sharp contour with a LOT of paint,
as it is so easy to sand through. Then treat those
edges like a virgin when you sand. I'm very pleased
with the finished product, and would not hesitate to
do it again.
Brian Bange

[[email protected]]

There is a phenomenal amount of "reiniventing the wheel" by the glider
community in regards to this subject, and especially in regards to
painting with PU or AU. There is a tremendous amount of information
on a web site called Autobodystore.com. They sell excellent
instructional videos in addition to hosting a great Forum. As you can
see on the forum, all of these paint systems are sanded on a regular
basis by auto refinishers.

As JJ pointed out, keeping a wet edge and overspray are No Big Deal if
you plan on scuffing up the paint edge and knocking the oversray prior
to painting the rest. Alas, not everyone is aware of this -
inlcuding the high quality body shop who shot the K21 wing I spoke
of.

Refinishing a kilo-dollar glider by yourself using techniques and
materials you evolved from trial and error is not where I would get my
first experience in this type of work. Additionally, buying a
refinished glider is a bit of a leap of faith if the finish is less
than 5-ish years old. It is difficult to know how well all of the
prep and reacoating was done in less time.

The web site above is a great resource. Check it out!

[JJ Sinclair]

Just bought 2 gal of PPG Concept AU (over 3 gal when mixed) Toyota
Super White 90288 and 2 gal of PCL Polyprimer
(white)...........................$1032.00 The control surfaces on the
DG-300 I'm rebuilding have been stripped, filled, sanded with 80g
followed be 220 dry and look good to go for painting. I use a 4 power
magnifying glass with a drop lite to spot anything I missed (old
eyes). The 80 grit scratches will disappear on the second coat and
will insure a good "tooth" is given to the paint which is important
anywhere you will be taping (wing roots).

One thing that hasen't been mentioned is a good water trap. All
compressors produce water and it must be trapped or your paint job
will be pock-marked with thousands of little craters caused when water
droplets form on the spray nozzle. I use a toilet-paper water trap and
it does the job, just replace the roll before each new
job...........................you can even dry out the old filter and
use it for its origional purpose!
Cheep-o, JJ

[01-- Zero One]

How about some details about the toilet paper dryer, JJ.



Cheap-o, II.



Larry





"JJ Sinclair" > wrote in message
:

> Just bought 2 gal of PPG Concept AU (over 3 gal when mixed) Toyota
> Super White 90288 and 2 gal of PCL Polyprimer
> (white)...........................$1032.00 The control surfaces on the
> DG-300 I'm rebuilding have been stripped, filled, sanded with 80g
> followed be 220 dry and look good to go for painting. I use a 4 power
> magnifying glass with a drop lite to spot anything I missed (old
> eyes). The 80 grit scratches will disappear on the second coat and
> will insure a good "tooth" is given to the paint which is important
> anywhere you will be taping (wing roots).
>
> One thing that hasen't been mentioned is a good water trap. All
> compressors produce water and it must be trapped or your paint job
> will be pock-marked with thousands of little craters caused when water
> droplets form on the spray nozzle. I use a toilet-paper water trap and
> it does the job, just replace the roll before each new
> job...........................you can even dry out the old filter and
> use it for its origional purpose!
> Cheep-o, JJ

[Gliderphud]

On Jan 10, 7:32 am, JJ Sinclair > wrote:
> Just bought 2 gal of PPG Concept AU (over 3 gal when mixed) Toyota
> Super White 90288 and 2 gal of PCL Polyprimer
> (white)...........................$1032.00 The control surfaces on the
> DG-300 I'm rebuilding have been stripped, filled, sanded with 80g
> followed be 220 dry and look good to go for painting. I use a 4 power
> magnifying glass with a drop lite to spot anything I missed (old
> eyes). The 80 grit scratches will disappear on the second coat and
> will insure a good "tooth" is given to the paint which is important
> anywhere you will be taping (wing roots).
>
> One thing that hasen't been mentioned is a good water trap. All
> compressors produce water and it must be trapped or your paint job
> will be pock-marked with thousands of little craters caused when water
> droplets form on the spray nozzle. I use a toilet-paper water trap and
> it does the job, just replace the roll before each new
> job...........................you can even dry out the old filter and
> use it for its origional purpose!
> Cheep-o, JJ

JJ,

What do you use to build up after removing the old gelcoat?

Why AU versus PU?

Phud

[JJ Sinclair]

On Jan 10, 8:54*am, "01-- Zero One" > wrote:
> How about some details about the toilet paper dryer, JJ.
>
> Cheap-o, II.
>
> Larry

I've had mine for some time, but I believe I paid $50 bucks for it at
the local automotive paint store. Just roll off a few sheets and it
fits in nice and snug. A compressor working hard will send moist air
right to the spray gun without a chance for it to condense and form as
water inside the holding tank, which one always drains before every
painting episode.
JJ

[JJ Sinclair]

On Jan 10, 9:15*am, Gliderphud > wrote:
> On Jan 10, 7:32 am, JJ Sinclair > wrote:
>
>
>
>
>
> > Just bought 2 gal of PPG Concept AU (over 3 gal when mixed) *Toyota
> > Super White 90288 and 2 gal of PCL Polyprimer
> > (white)...........................$1032.00 The control surfaces on the
> > DG-300 I'm rebuilding have been stripped, filled, sanded with 80g
> > followed be 220 dry and look good to go for painting. I use a 4 power
> > magnifying glass with a drop lite to spot anything I missed (old
> > eyes). The 80 grit scratches will disappear on the second coat and
> > will insure a good "tooth" is given to the paint which is important
> > anywhere you will be taping (wing roots).
>
> > One thing that hasen't been mentioned is a good water trap. All
> > compressors produce water and it must be trapped or your paint job
> > will be pock-marked with thousands of little craters caused when water
> > droplets form on the spray nozzle. I use a toilet-paper water trap and
> > it does the job, just replace the roll before each new
> > job...........................you can even dry out the old filter and
> > use it for its origional purpose!
> > Cheep-o, JJ
>
> JJ,
>
> What do you use to build up after removing the old gelcoat?
>
> Why AU versus PU?

The PCL Polyprimer 907 white (PE) goes on smooth and contours easily
with 80 grit on a 18" rubber board. I spray on 1 coat over everything
and 2 coats over any repairs or known low areas after Gold Bond (new
Bondo type heavy filler) on and around the repair of the tail feathers
and flaps and ailerons. For the stripped fuselage and wings, I shoot
on 2 heavy coats and contour 45 left, then 45 right........Hopefully
without the need to re-prime any low areas. You can touch the glass,
but musn't keep sanding these areas or old Mr. pin-hole will rear his
ugly head. Best to stop, mark the low areas and shoot on another
primer coat. Before I start sanding the primer, I use body putty on
all the defects that show easily. Level the wing before starting to
contour, don't just use 2 saw horses..........you need a third one
about the inboard end of the aileron.
AU is the latest and greatest, not as soft as PU, but still softer
(more pliable) than gel-coat. I shoot about 4 coats or until I see
good orange-peal everywhere, the 4th coat may be a "leveling" coat
with a tad more thinner and the pressure dropped, fan open and gun
held 12" from the surface to "fog" on a leveling coat which will also
pick up a lot of the overspray. Wet sand it with 600W after 12 hours
while its quite easy, followed by 800W, then let it cure for 3 days
before buffing-out. I fog on a very thin lacquer coat that sits in the
orange-peal..................then 3M guide coat for the 800W.

[Richard[_1_]]

On Jan 10, 8:54*am, "01-- Zero One" > wrote:
> How about some details about the toilet paper dryer, JJ.
>
> Cheap-o, II.
>
> Larry
>
> "JJ Sinclair" > wrote in message
>
> :
>
>
>
> > Just bought 2 gal of PPG Concept AU (over 3 gal when mixed) *Toyota
> > Super White 90288 and 2 gal of PCL Polyprimer
> > (white)...........................$1032.00 The control surfaces on the
> > DG-300 I'm rebuilding have been stripped, filled, sanded with 80g
> > followed be 220 dry and look good to go for painting. I use a 4 power
> > magnifying glass with a drop lite to spot anything I missed (old
> > eyes). The 80 grit scratches will disappear on the second coat and
> > will insure a good "tooth" is given to the paint which is important
> > anywhere you will be taping (wing roots).
>
> > One thing that hasen't been mentioned is a good water trap. All
> > compressors produce water and it must be trapped or your paint job
> > will be pock-marked with thousands of little craters caused when water
> > droplets form on the spray nozzle. I use a toilet-paper water trap and
> > it does the job, just replace the roll before each new
> > job...........................you can even dry out the old filter and
> > use it for its origional purpose!
> > Cheep-o, JJ- Hide quoted text -
>
> - Show quoted text -

I believe this is the filter

http://weilerwelding.com/shopsite_sc/store/html/motorguard.html

MOTORGUARD AIR FILTER, M-60
MOTM-60
MOTORGUARD AIR FILTER/DRYER M-60 - Eliminates moisture from air supply
line. Submicronic compressed air filter. Straight -through piping
design. 1/2in NPT pipe size. 5in x 7in. Uses M-723 filter elements.

I think the fiter element can be replaced with single ply toilet
paper.

Price has cheaped or creeped to $75.99. How old are you JJ?


Richard
www.craggyaero.com

[JJ Sinclair]

On Jan 11, 6:10*am, Richard > wrote:
> On Jan 10, 8:54*am, "01-- Zero One" > wrote:
>
>
>
>
>
> > How about some details about the toilet paper dryer, JJ.
>
> > Cheap-o, II.
>
> > Larry
>
> > "JJ Sinclair" > wrote in message
>
> :
>
> > > Just bought 2 gal of PPG Concept AU (over 3 gal when mixed) *Toyota
> > > Super White 90288 and 2 gal of PCL Polyprimer
> > > (white)...........................$1032.00 The control surfaces on the
> > > DG-300 I'm rebuilding have been stripped, filled, sanded with 80g
> > > followed be 220 dry and look good to go for painting. I use a 4 power
> > > magnifying glass with a drop lite to spot anything I missed (old
> > > eyes). The 80 grit scratches will disappear on the second coat and
> > > will insure a good "tooth" is given to the paint which is important
> > > anywhere you will be taping (wing roots).
>
> > > One thing that hasen't been mentioned is a good water trap. All
> > > compressors produce water and it must be trapped or your paint job
> > > will be pock-marked with thousands of little craters caused when water
> > > droplets form on the spray nozzle. I use a toilet-paper water trap and
> > > it does the job, just replace the roll before each new
> > > job...........................you can even dry out the old filter and
> > > use it for its origional purpose!
> > > Cheep-o, JJ- Hide quoted text -
>
> > - Show quoted text -
>
> I believe this is the filter
>
> http://weilerwelding.com/shopsite_sc/store/html/motorguard.html
>
> MOTORGUARD AIR FILTER, M-60
> MOTM-60
> MOTORGUARD AIR FILTER/DRYER M-60 - Eliminates moisture from air supply
> line. Submicronic compressed air filter. Straight -through piping
> design. 1/2in NPT pipe size. 5in x 7in. Uses M-723 filter elements.
>
> I think the fiter element can be replaced with single ply toilet
> paper.
>
> Price has cheaped or creeped to $75.99. *How old are you JJ?
>
> Richardwww.craggyaero.com- Hide quoted text -
>
> - Show quoted text -

Yep, that's it....................When I was born, they hadn't
invented toilet paper, yet! I'm 3 days older than dirt.
JJ