Primer Wars - Survey

Hello to all, I have just started building my tail kit, and am debating the primer wars. There are vocal people on each of the sides, but I am trying to get a better feel for how many are going each direction, thought a survey would help.

I can't properly vote; put me down for no priming, alodine and epoxy primer, and no-scuff before self-etching primer. And I qualify the no priming by saying all non-alclad gets primed, and some high-wear surfaces have even been powder-coated.

To clarify the variety of answers, the wings and tail of my -6A were done by a professional who etched, alodined, and then used AKZO on each part. After I moved to Flagstaff, I got another painter who used a different primer (no, I don't know what it was) which cracked and peeled easily, so I ended up re-priming with SEM in a rattle-can. The SEM is almost as tough as the AKZO with no surface prep other than to wipe with mineral spirits or naptha to clean and remove oil. I have been happy with both methods of priming in my -6A.

On the -10, weight is going to be a big issue (too many bells and whistles) and I live in a non-corrosive environment, so I am foregoing primer on most alclad parts. I am hoping that at least part of the exterior will be polished (still working on paint schemes) but for certain the cabin will be primed - I'm holding off on that until the interior shop gets hold of it. I don't regret priming the -6A but I'm not going to be very worried about the -10. So there you have it; I'm definitely on the fence, maybe.

What I did was not on your list.

Scotch bright, alumini prep, alodine, then paint with SEM Self Etching Primer in rattle cans. Easy to clean up; wipe the tip and put it back on the shelf. Good coverage, and no signs of any age after five years.

It was sort of the belts, suspenders, and duck tape approach to corrosion protection.

PS. Welcome to the VAF forum.

I tried to chose what seemed the most popular options. We are homebuilders after all if I put every different thing someone did it would be a list a mile long

N941WR said:

What I did was not on your list.

Scotch bright, alumini prep, alodine, then paint with SEM Self Etching Primer in rattle cans. Easy to clean up; wipe the tip and put it back on the shelf. Good coverage, and no signs of any age after five years.

It was sort of the belts, suspenders, and duck tape approach to corrosion protection.

PS. Welcome to the VAF forum.

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What Bill said +1

yup

lorne green said:

What Bill said +1

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+2..........

Scotchbrite, AFS Etch, AFS Primer.

My approach was varied. First on skins I did nothing. Ribs and stringer in "dry" areas I primed. In wet areas and areas that would be hard to access later I, treated primed and top coated.

I used rattle can self-etching primer and top coated with rustoleum enamel. It was easy, not necessarily the highest quality. I know altogether I used 12-16 cans of primer and about 6 of the enamel. I figure 50% is in the ozone and the rest on the plane. Probably added about 10-12 lbs to the plane, shortened my life by about a week and aided global warming. (I am from Wisconsin so that's okay).

[email protected] said:

Hello to all, I have just started building my tail kit, and am debating the primer wars. There are vocal people on each of the sides, but I am trying to get a better feel for how many are going each direction, thought a survey would help.

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Welcome to VAF and RV-dom, Bill!

However, you have started your journey by jumping into a lake full of quicksand. There ain't no way you will settle anything with this survey.

When all is said and done, it really doesn't matter what everybody else is doing. You need to evaluate your situation and builder sensibilities and move forward accordingly. Rest assured any RV will outlast all of us even if there isn't a drop of primer on the plane. I wrote a little blurb many years ago while early in my RV-6 project and thousands of RVs later it stills forms the nucleus of my opinion on this subject:

http://thervjournal.com/priming.html

Best wishes for a most enjoyable project,

Yes, I realize that my first post fanning the primer wars might not have endeared me, but it is something that I was very currious about. Often (as this survey shows) by reading posts (Great information in my opinion as to all the pro's and con's of priming), and by reading some of the popular building blogs, I had the impression that 60-70% were using epoxy based primers (definately the most protection), and 30-40% were using self etching. So far that appears to be the oposite of what is actually being done, with the majority using self etching. I do totaly agree that where your plane is going to be based should have a impact on it.

In the future I will probably put up a lot more surveys about mods that I am considering, as it is nice to know if you are going way out on a limb with a mod that you read about, or if it is somewhat common... Such as rudder trim, many people blog about different rudder trim mod's, but how many people are actually doing them? If 80% are adding some sort of rudder trim after the fact, then I should probably add it while I build. If only 20% are, then I might wait until I get it flying and determine myself if I think it is needed.
(I have rudder trim on my 182 and never change it).

I wish this site had a whole survey section that all sorts of common mods and techniques were listed. (Such as how much deburring,priming, self painting... people are doing)

Bill

[email protected] said:

I wish this site had a whole survey section that all sorts of common mods and techniques were listed. (Such as how much deburring,priming, self painting... people are doing)

Bill

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In a practical sense, the entire VAF forum structure is a "survey section". By reading the forums on a consistent basis and diligently using the search engine, a builder can get a pretty good grasp on the predominate building schemes currently in use.

Every RV is a custom aircraft as the above poll quickly illustrated. The huge variability of amateur-built aircraft can be unsettling and hard to grasp for builders coming out of the strictly regulated standard category community. But we embrace the experimental certificate and all the wonderful innovations it has made possible.

Enjoy!

Bill, I think you're spot on.

Like you, I'm at the front end of a build project and I think a survey accomplishes multiple things, just as you've outlined. Sam states the obvious (yes, we must each saddle our own horse...) but, first off, numbers offer perspective. (Tho' more responses would offer a clearer perspective). Second, the subsequent posts, which included 'sorta', 'mix & match' examples, fill in the survey's limited categories. And third, to the extent surveys foster more surveys, that can only be useful grist for anyone's mill.

Thanks for the survey. It certainly produces a perspective that, so far and for me, is absent from the various threads on this topic I've been reading.

Jack

No priming no problems no wars. Voted for peace.

Since there is no poll option for pie I vote for scuffing, etching, alodine, and Epoxy primer on any surface that gets painted. Unless you live on the East or Left coast no primer is really needed unless you just want it.

Do it!

KTM520guy said:

Since there is no poll option for pie I vote for scuffing, etching, alodine, and Epoxy primer on any surface that gets painted. Unless you live on the East or Left coast no primer is really needed unless you just want it.

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Having sold a couple RV's and one project, I would say primer it anyway because buyers seem to want that. Yes, someday you will sell your pride and joy, or survivors will... I had one that was alodined in the rear fuse and looked just beautiful...

You won't go wrong by following manufactures recommended procedures. I believe Vans used no primer on some of there's with acceptible results. Alodine is itself a primer and Dupont advised a friend that was all necessary for applying Imron. Be carful and not apply too much alodine as a thick layer will eventually crack. A gold color is too much. Remember the weight issue. Paint is another compromise issue in building the RV

Alodine is a conversion coating and is used to prevent corrosion and to get the primer to stick. I doubt the weight of the alodine treatment could be measured.

KTM, I'm no certainly expert, but I totally agree with the method you describe. I alum. prep by etching, alodine, allowed to dry then epoxy primed. I used Randolph epoxy primer. I did all interior parts. Unfortunatly I did not feel I was proficient for painting the exterior. I don't recall the primer they used but it already shows signs of lifting in small areas including under screws. The interior has no signs of peel or lifting with the numerous install and unassembles during the construction.
Parts painted as above have been removed and remanufactured for changes in plans. We have bent them and still no lifting. It can be scraped off but you have to either try hard or be very rough installing to cause a problem. Solvents also don't touch the stuff. As for spray can paint that we have tried, will wipe off with most solvents.
Ron

I first did just rattle self etch, then a few areas started to peel up, then scotchbrite and then rattle can self etch, good to go. Now on the exterior paint, it will be scotchbrite, degrease, tack cloth, epoxy primer wet sand, repeat if needed, base, intermediate clear, airbrush work, clear.

I struggled with the primer question until my empennage kit arrived. The skins are pretty easy to keep pristine (and not harming the alclad) but that has not been the case for most everything else that needs to be drilled, deburred, etc. By the time I finish preparing these parts there is enough small scratches and finger print marks that something needs to be done. For me that's wiping down with Acetone, scotchbrite scuffing, Acetone wipe again, and then Napa 7220.