The International Cessna 170 Association

Getting very close to painting my 55'. It has been completely stripped, been going over rivet heads and the hard to reach areas. I am about to go crazy! Anyone here ever heard of doing the Aluma Prep process and then onto the Alodine but instead of washing the Alodine off, letting it dry and sanding evenly and using that as your primer rather than also priming? Then obviously shoot the base coat actual paint of choice.

Seems I always heard to wash the Alodine off and let dry and then shoot primer and then paint...

Advice from anyone who has gone through painting much appreciated.

You should rinse the alodine off. You can't rinse too much.
You may be confusing the alodine process with etching. There are products that will etch the alclad, then apply primer........and are also "self etching" primers. These processes have evolved since I last slept, so best to talk to someone who is familiar with recent techniques

Just a ssuggestion, because of environmental concerns today's paint strippers are not as effective as the old products. I'd take a magnifying glass and have a good look at the rivet heads to ensure there's no edge whiskers or eyes that will be liberated from the rivets during the painting process. Also new EP sensitive primers may not stick as well as the old primers making correct prep even more important.
As for making painting mistakes, I'm saying, it's just that easy. Don't ask me how I know how harsh it is to strip and prep a set of wings after making a mistake and having to spend another $ 1500 on product which is nothing compared to the time and effort, to do it all over again.
I've not heard of not neutralizing the acid. I'm also puzzled, why you would want to contaminate the surfaces by sanding them to partially remove the conversion coating after creating it? These are Ideas I'd run from myself.
Lastly paint supplies are getting expensive, stupid like.

My plane is being painted right now. We're using PPG DX533 but the process is basically the same. You will want to wash the alodine off and let it dry before priming. Letting the alodine dry on the metal can cause blistering of the paint down the road. You should prime as soon as practical after the alodine has been rinsed to avoid further oxidation. You can use heat and compressed (clean) air to help with the drying. Work in sections.


http://www.chemical-supermarket.com/fil ... lletin.pdf

I am by no means a professional painter, but having just finished painting mine the process is still pretty fresh to me.
Strip to bare metal. I was told it was ok to leave existing primer on. That was a mistake.
Wash with aluma prep. Keep it wet for several minutes then rinse it off.
Now put on the alodine, again keep it wet for several minutes, then rinse.
Tape off.
Wipe down with a prep all type of solution.
You can put top paint straight onto the prepared aluminum but I put down a white 2k epoxy primer and 45 minutes later the white polyurethane top coat. Kind of hard to spray white over white. But it will keep it bright even after fading.

It you want to ask anything specific send me a private msg with your number and I'll give ya a call.

Just please keep in mind these chemicals are nasty. Proper protective gear is a must.

Another option if you don't want to mess with chemicals, is to use a 3M wrap material. I worked with a local graphics company to create a full size template from some 1950 A model pictures and measurements . It applied well and has held up excellent thus far. This aircraft was already stripped when I bought the project, so I went with an original look. This is the same material used on cars, airplanes and boats. If you ever got tired of it, you could peel it off and do something else, and repairs ot touch up is very easy too.. Now as far as who stripped the vertical near the N-Number with a putty knife, well I'd like to find them...

Rick

Apparently I was a bit misunderstood and have since been straightened out regarding the Alodine stage. You do in fact wash it off like you should. However here is where it still gets wierd. The painter I am working with paints jets, Cessnas, fancy homebuilts etc. he goes from the Alodine stage to an etch primer and then scotch brites to scuff it and lays the single stage top coat over that. Everything I read and advice I have received is different than this. You just epoxy prime and then your top coat if you do the whole alodine process. If you'd wanted to skip the prep and do it the "lazier" way then you just shoot etch primer and then another primer/sealer and then your top coat/final coat.

My head is spinning on what to do as I have a professional painters help but it contradicts what the data sheets say and advice of people who have also painted before.

Not criticizing anyone at all....
...but I've had "professionals" screw up some pretty simple jobs.

Kyle,
There is more than one "right" way to paint an airplane. I would not overthink it. The main thing is to have a clean scuffed/etched aluminum base. These days there are many paint systems available and they all have different methods. Many people even skip the alodine process altogether. With the newer epoxy primers out there one could simply clean and etch the aluminum and then shoot the primer on the clean/etched metal. You could even go waterborne with Stewerts. I don't believe they use alodine with their system.

Some of the experimental guys are now shooting silver instead of white to cut down on the amount of paint needed, which costs and weighs less.