Nason SelfEtch Application info...!?

Hey guys,

I just have a simple question regarding the application of the following primer;
Nason 491-55 Self-Etch Chromate Free Primer

I have some parts that have been alumi-prep and alodined and are now ready to prime.. is it ok to put this primer on top or do I absolutely need an Epoxy Primer?

Also, would be a good solution to just skip the alodine part for alclad parts and just shoot this primer on them with just a simple cleaning of the part with acetone or alcohol? Or again, it's better to use an epoxy prime on top of alclad parts?

I know there may already have some answer to this question in the following forum but I tried the search and there are soooo many ideas I don't know where to start...

I just know that from my A&P classes, almost all aircraft parts for general aviation are alumi-prep, alodine then primed...

Thanks

Welcome, Carl! You're right, there's certainly a lot of info on priming here (and even more opinions). I don't have an answer for you, but someone with Nason experience probably will. Lots of people are using just self-etching primers, and others swear by epoxies.

Enjoy your -9 build. It's a great airplane.

--
Stephen

CMBAero said:

Hey guys,

I just have a simple question regarding the application of the following primer;
Nason 491-55 Self-Etch Chromate Free Primer

Click to expand...

I am shooting Nason 491-17 primer with 441-43 activator reducer. I don't alodine any of the parts. I scuff, wash with blue Dawn dishwashing soap and wipe with Acetone or Lacquer thinner. It seems to stick well and is durable.

I'm not sure what the 491-55 primer is. The 491-17 is also a self etching primer.

If you buy a gallon kit, ask your paint shop for a mixing lid. It has a handle, thumb trigger for pouring and a built in mixing paddle. I put my chord less drill on the mixing shaft, mix well and pour out of the gallon can. No lids to fool with and it is easy to pour small quantities directly out of the gallon can.

These are the lids they use on their base colors when they are mixing.

Nason primer ++++

CMBaero, I confirm the suggestion that Scotchbright scuffing and a good degrease cleaning is all you need. Adhesion is excellent, even under aggressive finish coats like Stits Aerothane or Imron. The only downside, compared to epoxy, is solvent resistance. Lacquer thinner removes it if you rub very long with wet rag.

Thanks all for your answers!

Just a little clarification I still need... can this primer be shooted on top of alodined parts?

DaAV8R said:

I'm not sure what the 491-55 primer is. The 491-17 is also a self etching primer.

Click to expand...

I just looked at both description of products of the 491-55 and the 491-17 and I think the only difference I can see is that the 491-55 is chrome free...

Larry DeCamp said:

CMBaero, I confirm the suggestion that Scotchbright scuffing and a good degrease cleaning is all you need. Adhesion is excellent, even under aggressive finish coats like Stits Aerothane or Imron. The only downside, compared to epoxy, is solvent resistance. Lacquer thinner removes it if you rub very long with wet rag.

Click to expand...

The only thing I don't really understand is why scotchbright the part... I know it's to help the paint hold better, but don't we damage the alclad protection by scratching it like that?


Thanks!

CMBAero said:

...
The only thing I don't really understand is why scotchbright the part... I know it's to help the paint hold better, but don't we damage the alclad protection by scratching it like that?


Thanks!

Click to expand...

Red or grey ScotchBrite won't take off the Alclad layer, but will help mechanical adhesion.