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SGS 1-23



 
 
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  #1  
Old November 23rd 18, 06:23 AM posted to rec.aviation.soaring
[email protected]
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Posts: 22
Default SGS 1-23

We have our ship sanded and exposed metal primed
Have sprayer
Our painting skills are in “dangerous amateur”
category
We are committed to DIY
Suggestions on paint type and brand?
  #2  
Old November 23rd 18, 07:33 AM posted to rec.aviation.soaring
Darryl Ramm
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Posts: 2,403
Default SGS 1-23

On Thursday, November 22, 2018 at 9:23:22 PM UTC-8, wrote:
We have our ship sanded and exposed metal primed
Have sprayer
Our painting skills are in “dangerous amateur”
category
We are committed to DIY
Suggestions on paint type and brand?


Key info missing. You did not strip it? Do you understand what paint is on the aircraft already? What did you treat and prime the bare aluminum patches with?

What does the A&P supervising and signing off on your work recommend?
  #3  
Old November 23rd 18, 11:36 AM posted to rec.aviation.soaring
Cookie
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Posts: 152
Default SGS 1-23

"sanded" ???!!!!

As in sanded with a power sander? OR sanded by hand with sand paper?

Not good! You don't "sand" aluminum airplanes! (not the bare metal)

Metal airplanes are "stripped" using chemical strippers, or (sometimes) blasted with plastic bead media, or sometimes "soda blasted")

There are pros and cons to each method...and each needs to be done professionally.

"Sanding" ...puts scratches on the metal surface...scratches in aluminum can easily lead to cracks..structural damage.

Chemical stripping can leave chemicals in the seams, rivets, and other places it should not be....corrosion later.

Blasting media can be easily "over done" causing overheating of the surfaces, and warping...


Beyond that..preparation of aluminum for painting is a detailed, involved process. Done incorrectly, the paint will soon fail. Getting paint to adhere to aluminum is tricky

Usually you need to treat with "Alumaprep" which is a cleaner and "etcher" to get every last trace of dirt and oil off the aluminum. Next step is to apply Alodine solution. This is a "conversion coating"...which chemically changes the surface of the aluminum to a new compound, one which will allow the adherence of primer.

In the old days the primer of choice was zinc chromate... Durable, corrosion resistant, and good adhesion. Now hard to get...dangerous to use.

Many now use an AIRCRAFT type epoxy primer...also good adhesion. It is possible to find a "high build" primer, which can be LIGHTLY sanded between costs to smooth out problem areas. Do not sand into the metal though!

Top coat should be a polyurethane AIRCRAFT topcoat paint. Avoid automotive paints, although they may seem to be the same stuff...autos are typically made of steel, and are very stable. Airplanes are aluminum, are very bendy, flexible, and have many seams and rivets etc.

BTW..."typical automotive "base color coat /clear coat" jobs on airplanes look great for a while but the clear coat almost always fails and peels..

Polyurethane paint is highly toxic to the amateur painter...you need a full Tyvec suit, gloves, hood, tight fitting full face mask, and remote air supply.

For a brand name...Superflight...

But you can look at Aircraft spruce catalog and see other brands and SYSTEMS of painting aluminum airplanes.

Then...you may have to pre-weigh, and later mass balance the control surfaces...Whole airplane will need new W&B...Log book sign off by A&P...


Yes, you CAN do a quality DIY airplane paint job...homebuilder so it all the time....but it is not so easy to do it right...

A "professional" job is very expensive (you get what you pay for)...but done properly it has to be expensive...well worth the money IMHO.


Cookie

PS....the above is based on my personal experience...having built and painted two airplanes, and having painted and restored a bunch more.

Be ready for some arguments...for every different painter, you will get a different set of advice!







On Friday, November 23, 2018 at 12:23:22 AM UTC-5, wrote:
We have our ship sanded and exposed metal primed
Have sprayer
Our painting skills are in “dangerous amateur”
category
We are committed to DIY
Suggestions on paint type and brand?


  #4  
Old November 23rd 18, 04:16 PM posted to rec.aviation.soaring
Scott Williams
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Posts: 198
Default SGS 1-23

On Thursday, November 22, 2018 at 11:23:22 PM UTC-6, wrote:
We have our ship sanded and exposed metal primed
Have sprayer
Our painting skills are in “dangerous amateur”
category
We are committed to DIY
Suggestions on paint type and brand?


Free advice is always worth what you pay,However, FWIW, I have been an amateur body man and auto refinisher since the '70's. Working on my own vehicles.
I highly recommend Poly Fiber (Consolidated Coatings) Ranthane.
I have sprayed Old school Laquers, Cronar, ppg 2ks, etc.
I have refinished a Schempp Hirth SHK and am currently in the middle of refinishing a standard cirrus using ranthane.
Nothing has performed half as well as ranthane for gloss and ease of application.
But! buy the poly fiber manual, read and understand it,
follow the instructions to the letter! employ bright lights and safety measures!
Buy good equipment, cleanliness counts,
Practice spraying on junk panels, and resist the frequent temptation to take shortcuts.
painting DIY involves taking the risk of having to do it more than once,
and lastly, set high standards, then be willing to accept less than perfect results. there is a reason refinishing is expensive.
Good luck and don't hurt yourselves.
Scott

  #5  
Old November 23rd 18, 05:23 PM posted to rec.aviation.soaring
[email protected]
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Posts: 22
Default SGS 1-23

Thanks to all for suggestions
To clarify
We did not strip old paint
We wet sanded and exposed some aluminum
In random places
The ship is still 95% covered in old paint yet
100% of surface wet sanded
We covered exposed metal with etching primer
We will be spraying without a booth,outside on a dry no wind day
  #6  
Old November 23rd 18, 10:39 PM posted to rec.aviation.soaring
Scott Williams
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Posts: 198
Default SGS 1-23

On Friday, November 23, 2018 at 10:23:18 AM UTC-6, wrote:
Thanks to all for suggestions
To clarify
We did not strip old paint
We wet sanded and exposed some aluminum
In random places
The ship is still 95% covered in old paint yet
100% of surface wet sanded
We covered exposed metal with etching primer
We will be spraying without a booth,outside on a dry no wind day


Perhaps an equipment enamel with the optional hardener available at most farm and implement stores would be suited for your project. Atwoods, tractor supply etc. You might research painting and the effect of dewpoint and condensation on the freshly painted surface before you pick your day.
Good luck.
Scott.
  #7  
Old November 23rd 18, 11:15 PM posted to rec.aviation.soaring
Cookie
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Posts: 152
Default SGS 1-23

Cool!...sanding existing, well adhered paint is the way to go.

The suggestion of Ranthane above is a good one. This is an AIRCRAFT type polyurethane. There is also Aerothane...used to be a competitor...but I think Aircraft spruce bought up ALL of the paint companies and group them together today.

Each brand of polyurethane seems to spray a bit differently and may need different reducer, different technique, etc. Some painters seem to prefer one brand over the other just because it fits their particular painting technique.

I've used Aerothane as well as Superflight...polyurethanes. Hint: the first coat has to be thin, thin, thin...like a dusting. if you try to go heavy on the first coat...it will certainly run. Don't even try to get full coverage or full color...wait for later coats...Once the first coat "tacks up", subsequent coats seem to stick well to the first coat and you can go a touch heavier on the paint....

Follow the directions that come from the manufacturer.

Using automotive paints or farm tractor paints is risky because some of these dry quite hard and "brittle" especially they brittle over time. airplanes flex a lot...so yu want a pint designed to take that. Yes auto paints can use a "flex" additive (used for car's plastic bumpers?..But why not use a proven brand of Aircraft paint such as Ranthane?

I've successfully painted outside. If the weather is warm enough, and dry enough...no problem...windy no good...but a very light breeze will take away the over spray nicely! Painting inside without strong exhaust fans will make a mess of your work as the overspray will build up where you're not painting and leave a rough surface!

Of course there was the time I was trying to get a Pawnee finished ...it was getting late, outside, getting dark ...had some spotlights....got the fuselage nicely painted...then the light attracted a swarm of mosquitos! They are now permanently preserved, and sanded smooth under a couple coats of paint!




Cookie
..

On Friday, November 23, 2018 at 11:23:18 AM UTC-5, wrote:
Thanks to all for suggestions
To clarify
We did not strip old paint
We wet sanded and exposed some aluminum
In random places
The ship is still 95% covered in old paint yet
100% of surface wet sanded
We covered exposed metal with etching primer
We will be spraying without a booth,outside on a dry no wind day


  #8  
Old November 24th 18, 12:27 AM posted to rec.aviation.soaring
Darryl Ramm
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Posts: 2,403
Default SGS 1-23

On Friday, November 23, 2018 at 2:15:36 PM UTC-8, Cookie wrote:
Cool!...sanding existing, well adhered paint is the way to go.

The suggestion of Ranthane above is a good one. This is an AIRCRAFT type polyurethane. There is also Aerothane...used to be a competitor...but I think Aircraft spruce bought up ALL of the paint companies and group them together today.

Each brand of polyurethane seems to spray a bit differently and may need different reducer, different technique, etc. Some painters seem to prefer one brand over the other just because it fits their particular painting technique.

I've used Aerothane as well as Superflight...polyurethanes. Hint: the first coat has to be thin, thin, thin...like a dusting. if you try to go heavy on the first coat...it will certainly run. Don't even try to get full coverage or full color...wait for later coats...Once the first coat "tacks up", subsequent coats seem to stick well to the first coat and you can go a touch heavier on the paint....

Follow the directions that come from the manufacturer.

Using automotive paints or farm tractor paints is risky because some of these dry quite hard and "brittle" especially they brittle over time. airplanes flex a lot...so yu want a pint designed to take that. Yes auto paints can use a "flex" additive (used for car's plastic bumpers?..But why not use a proven brand of Aircraft paint such as Ranthane?

I've successfully painted outside. If the weather is warm enough, and dry enough...no problem...windy no good...but a very light breeze will take away the over spray nicely! Painting inside without strong exhaust fans will make a mess of your work as the overspray will build up where you're not painting and leave a rough surface!

Of course there was the time I was trying to get a Pawnee finished ...it was getting late, outside, getting dark ...had some spotlights....got the fuselage nicely painted...then the light attracted a swarm of mosquitos! They are now permanently preserved, and sanded smooth under a couple coats of paint!




Cookie
.

On Friday, November 23, 2018 at 11:23:18 AM UTC-5, wrote:
Thanks to all for suggestions
To clarify
We did not strip old paint
We wet sanded and exposed some aluminum
In random places
The ship is still 95% covered in old paint yet
100% of surface wet sanded
We covered exposed metal with etching primer
We will be spraying without a booth,outside on a dry no wind day


You need to worry about what paint is on the surface already, and as Cookie suggests look at using a finish system suitable with what you have and itself. I would guess the original finish (if that is what you are sanding) is likely acrylic lacquer and you'll likely want to spray an epoxy sealer over that. You'll certainly want to test and look out for previous paint repair areas as well.

And get your A&P involved who is going to sign off this, and hopefully give you lots of advice, ... before you start doing stuff.

I've refinished/helped refinish cars and one aluminum GA aircraft long ago. For all the work involved and results and lasting benefits I'd probably sucker myself into stripping to bare aluminum, prep/anodize and paint with 2K polyurethane (requires good safety gear as noted). Actually I I know I'd only do some of it and pay a pro to spray in their shop. As with cars, its a lot of hard hard work and as others have said there is a reason it costs but the finish defines so much of the appearance of the glider that you'll hopefully enjoy for years/decades.

If you want inspiration for a 1-34 refinish look at Paul Bikle's altitude record breaking 1-34 at Hugh Bikle's the museum at Hollister, CA. Hugh had that refinished and it is just beautiful. I can't remember who did the refinish, I remember it being finished and talk about folks test flying it over a decade ago. https://sanbenito.com/2007/03/24/vin...or-san-benito/

I would stay away from enamels, the wrong type of paint.... unless you are painting tractors, engines etc..



  #9  
Old November 24th 18, 01:40 AM posted to rec.aviation.soaring
Cookie
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Posts: 152
Default SGS 1-23

I thought Bikle flew a 1-23, not a 1-34 ?


Cookie
  #10  
Old November 24th 18, 01:50 AM posted to rec.aviation.soaring
Cookie
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Posts: 152
Default SGS 1-23

The tactic I have used in the past, on a couple of aileron recover and paint jobs, and our club did on our Grob 103, and is going to do on our ls-3 refinish....

We do all the prep...stripping, sanding, recovering...sealing, prime and build coats...contour sanding, everything but the final top coats . This is because anything up to that point can be easily fixed if it is not correct..

For the final top coat of Polyurethane...we take the parts to a professional car paint guy...with a spray booth...great spray guns...and years of experience...

Painters like to paint...they hate prep work. So if we do all the "grunt work" (as in labor intensive)...the spray guy is happy to just do what he likes best...to spray top coat. They are fast too ...and our guy is very reasonable in price...because we did all the heavy labor...he just sprays and lets dry!

yes and amateur "can" get good results..but you also can make a lot of mistakes.

IMHO even the mediocre "pro" painter is better than the best amateur!

Cookie





 




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