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No Primer build....

YME

Active Member
After talking with different contributors on this forum, reviewing pros and cons of primed parts, and my local EAA Chapter input, I have decided to the unprimed assembly. As I live in Southern Nevada myself and others foresee no problems.

Now question is, do I wipe down all the parts with a cleaner (acetone, etc) after deburring where and when necessary and removing the blue film protector.

Thanks
 
A wipe with IPA(not the beer kind) is probably a good idea. It will take off the red mill markings.
Cheers DaveH
 
Glad to see it

Just finishing my 12is no-prime build, and I'm very happy I decided not to prime (with the exception, of course, of the parts required to be primed by the KAI...very few of them..)...I'm 68 and there is no way in hades the 12 will fall apart before I do.....

I also thing wiping is a good idea...I'm looking forward to a final wipe/clean before long...looking down that shiny tailcone is awesome!!... Almost like a silver C3PO... :D
 
Just finishing my 12is no-prime build, and I'm very happy I decided not to prime (with the exception, of course, of the parts required to be primed by the KAI...very few of them..)...I'm 68 and there is no way in hades the 12 will fall apart before I do.....

I also thing wiping is a good idea...I'm looking forward to a final wipe/clean before long...looking down that shiny tailcone is awesome!!... Almost like a silver C3PO... :D

Brian,

What did you use for primer?

-Tom
 
It’s everyone’s choice to make. I decided to do it on the three builds I have worked on.

I do it because:

  • My hand oils and aluminum don’t get along and it is virtually impossible to keep my parts looking nice and shiny. Primer gets everything looking all the same consistent color again.
  • Proper edge treatment and deburring will remove and scuff the Alclad and leave marks on the parts that get covered up by primer.
  • Some impact to long term corrosion protection. Likely the plane will outlive me either way but someone can enjoy it long after I am gone.
  • Airplanes tend to move to different geographical locations over time. My 7 went from humid East TN to the dry SLC Utah.
  • I am a glutton for punishment. LOL


Feel good in your decision! You’re the only one that you have to make happy about to prime or not.
 
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Azko

Brian,

What did you use for primer?

-Tom

Well, that is where I made a slight error...I used AZKO from Aircraft Spruce, which is a great product...but it's a two-part primer (two gallons total)...and then later decided not to prime, so I'm hip-deep in this somewhat expensive stuff.

There are so few parts in the -12 that require priming, I'll probably use the excess on an old car somewhere.. (sarcasm!)

If I were you, I would either try to buy a decent product in a smaller amount. You can even get self-etching primer in a rattle can, but I could not vouch for its quality. Again, at my age, I frankly don't give a hoot about priming. . No way the airframe will fail before I do, and I have no kids to leave it to....
 
Lots of good info and you’ve already made your decision but this may provide additional comfort. Just annualed my 1956 G35 Bonanza and it spent the first 30 yrs of its life in the Midwest. Everything we decide not to do makes for a lighter empty weight and IMO something we should all strive for.
 

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Brian, Brian, Marshall,

Again thanks for input and confidence boost. I will probably use self-etching primer in a rattle can where needed.

Brantel, you bring up a good point about de-burring and proper edge treatment for example after cutting the skin for installation of the landing light. Could buy an Alodine pen or maybe I am again over thinking.
 
SEM

Buy a case of SEM rattle can.
Some parts should be primed. The manual will tell you.
It's a perfectly good etch primer.
The other stuff, it's your plane. At the very least, a wipe with Isopropyl or Denatured Alcohol to remove contaminants.
 
Your profile shows Nevada?

NO PRIME - NO WORRIES. <g>. It'll outlast you for sure!

v/r,dr

After talking with different contributors on this forum, reviewing pros and cons of primed parts, and my local EAA Chapter input, I have decided to the unprimed assembly. As I live in Southern Nevada myself and others foresee no problems.

Now question is, do I wipe down all the parts with a cleaner (acetone, etc) after deburring where and when necessary and removing the blue film protector.

Thanks
 
Could buy an Alodine pen or maybe I am again over thinking.

Probably :rolleyes:

Properly executed trimming on any skins should result in the same edge condition as all of the skins have, so if it is justified for that, it should be done on every skin.

If used carefully and waste is minimized, one can of Sem primer (two at the most) would be enough to prime all of the parts specified on an RV-12.
 
SEM is a good product and easy to use. A fine mist (still able to see the red print) is all you need to prevent surface corrosion.
corrosion.JPGsemg.JPGsem.JPG
 
SEM

Only reason I say buy a case is because that one can always runs out at the worst possible time.
Plus, once you like a primer, you tend to find other uses for it.
Probably cheaper by the case too.
 
Per Van's instruction no primer needed except on extruded and non CLAD Aluminum parts.

Where ever steel attaches (even if steel is primed and painted), I etch, anodyne, prime the aluminum locally at the interface.

You can wipe it down with what ever you want, alcohol might be my choice and less aggressive than Acetone thinner.
 
no prime

Only primed dissimilar metals. The attached photo is this year and show 11 years of time and still looks good.
 

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I bought a bottle of Corrosion X and wiped a very very thin film on mating surfaces and where I deburred / sanded parts. This gives some protection without making a mess. Be careful to not apply too much. If corrosion X weeps out on to the exterior, it will make painting later more difficult.
 
Back in the day, The big 3 only primed interior parts if you coughed up extra cash when you wrote the deposit check, or if you ordered seaplane provisions.

There are jillions of 50 year old airplanes out there that still look like new inside all the unpainted nooks and crannies.

Having said that, I've seen a few that were absolutely turning to dust due to living their life in a salt air environment.

If I lived in Nevada or Arizona I wouldn't waste a minute considering it.
 
"CorrosionX"

Clean the parts. Once fully assembled AND painted, spray the non painted area with "CorrosionX". It will protect it and weep into all the nooks and crannies. Every annual wipe the areas with a cloth and reapply "CorrosionX" with a cloth.
 
I'm in SE New Mexico which is very dry also. I usually wear some of the 4mil Harbor Freight nitril gloves just to keep oils off of the skins. If I forget to put them on (and I do forget!), I'll often wipe them down with acetone. If the surface will be far from paint and solvents (like inside of wings) while the plane is being painted, I dont bother with the red print on the aluminum. If it stands a chance of coming in contact with a solvent (external surfaces, etc), I wipe the red lettering off with acetone as I really don't want red runny goop in my paint.

The only place I use primer is non-alclad, bare steel, or dissimilar materials (ie steal gear brackets bolted to aluminum bulkheads etc).
 
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Well... My RV-9A suffered corrosive soot incursion from a fire in hangar two down from mine. If it had been primed during construction, damage would have been much less, and cleanup probably lots easier.

Granted, the insurance adjuster works in the humid southeast, but he was emphatic that all planes should be primed. And if you sell your plane to a humid climate, how might that affect resale value?

Just another point to think about... but I'd probably make the same decision as you.
 
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