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Most Commonly Applied Primers

gregfuess

Well Known Member
I would start a poll, but I don't know the most commonly applied primers to include in it. While I live in arid and dry New Mexico, I plan to fly to coastal areas. And for general good practice, want to prime the interior.

While I prefer rattle cans for convenience, I am not against using a LPHV applicator and two part primer.

Also thinking a good surface prep would do no harm either, but don't know what kind for that, either. I've reached out to a few companies, AKZONobel and ZipChem, and getting a response is difficult. ZipChem did respond, but the rep copied lots of people, and I got lots of different responses. Not a consensus answer, which was a strike against them.

Any advise appreciated. Ordered all kits at the end of February, and the wing kit arrives first, and tomorrow.
 
I used Henkel's Alumiprep (cleaner) and 1201 Alodine (conversion coating), followed by PPG Super Koropon fluid resistant epoxy primer. Very satisfied with the results but it is a LOT of extra work. I don't think a rattle can primer can in any way compare. You'll need an HVLP gun (might as well get a good one).

https://krayden.com/technical-data-sheet/henkel_alodine_1201_technical_data_sheet/

https://www.ppgaerospace.com/Produc...-Koropon®-515X333-Fluid-Resistant-Primer.aspx

For the cockpit I used Sherwin Williams Jetflex WR applied over top of the epoxy primer. Did this with the individual parts before they were riveted together and like the results.

https://industrial.sherwin-williams...lex-wr-interior-aircraft-finish.10662939.html
 
Primers

If you don't mind dealing with the PPE, it's pretty hard to beat SW P60G2. Easy to shoot. Very light. Second choice would be an epoxy 2k primer.
If you want a water based, Stewart Systems is the top choice.
 
Stewart Ekoprime & Ekopoxy

I vary what I use depending on the area (and my mood). I've used Stewart Ekoprime for just about everything though. I love the fact that there is no real "pot life" like an epoxy primer, so if I have any left over, I can save it for the next spray session. It may not be as tough as epoxy, but for interior parts that never get touched or see the light of day after they're built, it works great and is very easy to deal with. I do keep a few rattle cans around for the random small parts when I don't feel like pulling out the spray gun. The rattle can approach is definitely not as tough as the Ekoprime, but again, I fail to see it mattering in most interior cases. That being said, I am switching over to Ekopoxy for interior cabin priming since that area does get touched and beat up over the life of the plane. I will have a full interior covering most of the cabin area, otherwise I would top coat with paint to get the ultimate in durability.
 
Since I’m doing QB fuse and wing, on the EMP so far I’ve done prekote wash and SEM’s ezcoat rattle can. I did testing with a few others and liked ezcoat. Because I’m not doing fuse and wings myself, is why I stuck with rattle can.
 
AKZO Epoxy Primer

I'm using the Akzo epoxy primer and am very happy with the results. Coating seems bullet proof once cured. Can even dimple after priming and it doesn't chip. The product I'm using is 463-12-8 and CA-116 for A and B.

I scuff with Scotchbrite and a pre-treatment called PreKote. Probably an overpriced degreaser but it has worked well. Some have mentioned using Bon Ami as a suitable degreaser. I think the key is to get your parts as clean as possible and scuff the surface adequately so the coating adheres mechanically.

The 3M Accuspray system is a game changer IMO. No cleanup to speak of which means less exposure to fumes etc. The 3M gun requires a fair amount of air volume so you'll need a decent sized tank on your compressor for large parts.

Use high-quality PPE and build some sort of booth to pull the vapors out. I'm fortunate in that my shop is not attached to the house. The fumes are strong even with good ventilation. It cures fast so I try to spray outside when the weather is suitable.

I also purchased two Rockler Mix Mates to store parts A and B. Allows me to mix them without being exposed to the fumes and makes it easy to pour out the right proportions without making a mess or wasting it.

Cons, it's somewhat expensive. I found a guy in Detroit that will sell it for $200 for a two gallon kit. AKZO lists distributors on their site so you might be able to find a seller near you. Spruce was like $400 and SkyGeek was over $300 + shipping last time I looked. I also wish the AKZO was a grey vs green. Unless you're going for a military look it's pretty ugly but it will be covered up for the most part.

Prepping and priming adds a fair amount of time to the build. My guess is 10-15% of my time is spent scuffing and priming.
 
If you don't mind dealing with the PPE, it's pretty hard to beat SW P60G2. Easy to shoot. Very light. Second choice would be an epoxy 2k primer.
If you want a water based, Stewart Systems is the top choice.

Any recommended, or the same question in a roundabout way, which are you using now?
 
Any estimates of how many gallons you'd need to completion?

My guess is 4 gallons total. 2 kits. Maybe more? I used most of a set on the empennage, but, I think I had the air pressure dialed up higher than necessary when I was learning how to use it. I was making a lot of overspray. The finish looks great but I was sending most of it through my spray booth. There's a balance between getting good atomization and wasting primer.
 
P60G2

Any recommended, or the same question in a roundabout way, which are you using now?

It depends. The interior of the airplane is all P60G2. I still spray it but very seldom as the airplane is almost done. Nothing to prime inside. Cockpit interior was sprayed with SW JetFlex over P60G2 before assembly so rivets would show. Bare steel parts get Napa 7220. Rattle can. I prime nutplates too. Fiberglass is primed and painted with Kirker EnduroPrime (2K Epoxy) and UltraGlo (Single stage Urethane).
The entire exterior got Alodined. It will be vinyl wrapped.
Tons of photos and tips on my blog.

If I build another, P60G2 would be my choice again except for cockpit. I would spray Enduroprime as a primer/top coat. It's hard as nails and comes in White, Gray and Black. One paint. Save weight.
 
If I build another, P60G2 would be my choice again except for cockpit. I would spray Enduroprime as a primer/top coat. It's hard as nails and comes in White, Gray and Black. One paint. Save weight.

Can you dimple with the applied primer on and have no separation? I see the primer quantity calculator spreadsheet, but maybe the priming is interspersed through the assembly log?

You use a HVLP gun to apply?
 
Dimpling

Can you dimple with the applied primer on and have no separation? I see the primer quantity calculator spreadsheet, but maybe the priming is interspersed through the assembly log?

You use a HVLP gun to apply?

You can. I don't normally, but I have dimpled after it cures.
One caveat with P60G2. It will wipe off with alcohol or solvents if you make marks and rub them off with a paper towel. It takes a bit of rubbing but it does come off. Alumiprep peels it right off like paint remover. P60G2 isn't a barrier like epoxy. It's a sacrificial layer. It reacts instead of the aluminum corroding.

Yes, most of the build was done with a DeVilbiss FLG. I bought a Harbor Fright Black Widow HTE when it was released. It's my favorite.

Priming is everywhere on the builder log. Early entries (empennage, wings) have quatity. Later I stopped logging it because the calculator is pretty accurate and easier to dial in.
 
PreKote + Stewart Systems EkoPoxy.

I chose it due to a low(-er) toxicity / health hazards. Personal protection is an individual choice, but I wanted a primer that I thought could be relatively safely used without a full gear, in a casual garage setting. Not a big expert on reading MSDS, but EkoPoxy one looked good to me.

So far I like how it sprays and how robust it is.
 
I alodine the interior and applied self-etching primer to the mating surfaces. The area that isn't seen by the occupant remained bare alodine because priming the confined area is a PIA. The main cabin was primed with automotive epoxy primer

All the exterior surfaces were adodine and primed using the automotive epoxy primer. It is fully cured and sandable after 2 -3 days. From the description from other poster, this stuff has a working time of about 2 hours compare to the other primer system that may have longer kick off time.

I am convinced any primer that can sufficiently blocks the air contact with the aluminum is good enough. From observation, the epoxy primer is so much tougher and than the self-etching primer.
 
Epoxy

I used 2 part epoxy, Southern Polyurethane brand (SPI). I reduce 10% and apply one thin coat. BonAmi and water clean, Alumiprep and alodine before prime. Very durable, can dimple without cracking, but I dimple before prime. It has UV inhibitor so I used it for cockpit area also without a finish coat.
 
I vary what I use depending on the area (and my mood). I've used Stewart Ekoprime for just about everything though. …

+1 to all of that. All that is needed is an okay’ish mask to keep overspray out of your nose, and a decent spray gun. I also use a $50 spray tent so I can spray outside. There are no fumes to worry about, so all the neighbors are happy.
 
How much primer for entire rv10

I am using Azko Nobel for my rv10 internal parts. I am just finishing up the elevator and already used an entire 2 gallon set of primer…. 1 set (2 gallons) primed HS, elevator, VS and rudder. What is the amount of primer I will most likely require for entire airframe. I hope it’s not too much. I thought this one set would go further than it did. I sprayed 2 light coats with the HF black widow HPE gun. Any support will be greatly appreciated.
Total weight is also on my mind as well as possible other options for fuse
 
Primer

I am using Azko Nobel for my rv10 internal parts. I am just finishing up the elevator and already used an entire 2 gallon set of primer…. 1 set (2 gallons) primed HS, elevator, VS and rudder. What is the amount of primer I will most likely require for entire airframe. I hope it’s not too much. I thought this one set would go further than it did. I sprayed 2 light coats with the HF black widow HPE gun. Any support will be greatly appreciated.
Total weight is also on my mind as well as possible other options for fuse

That sounds like a lot of primer. Just my opinion but Akzo is so tough, one light coat should be enough to protect. It's a barrier. Just a data point but I almost made it through my 7A on one gallon of P60G2.
 
Yea I thought so too ….. perhaps I was applying to much making sure everything was covered. I guess I could just stick with one light coat. Reason why I used 2 coats was because some aluminum was showing a bit… though I had to have everything totally “green(ed)” out.

I’m also going to see about paint gun settings.
 
I am using Azko Nobel for my rv10 internal parts. I am just finishing up the elevator and already used an entire 2 gallon set of primer…. 1 set (2 gallons) primed HS, elevator, VS and rudder. What is the amount of primer I will most likely require for entire airframe. I hope it’s not too much. I thought this one set would go further than it did. I sprayed 2 light coats with the HF black widow HPE gun. Any support will be greatly appreciated.
Total weight is also on my mind as well as possible other options for fuse

Wow! You need a mentor. I don't think that I used mush more than 2.5 gallons (5 gal total, mixed 1:1) of primer on my entire 10 and that was for the complete exterior and entire cabin, top and cowl interior. And that was two coats everywhere except some of the F/G parts that got 5 or 6 to deal with the awefull new grey gel coat problems.

I use southern polyurethanes. absolute top end quality and very affordable.

Larry
Larry
 
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Yea I thought so too ….. perhaps I was applying to much making sure everything was covered. I guess I could just stick with one light coat. Reason why I used 2 coats was because some aluminum was showing a bit… though I had to have everything totally “green(ed)” out.

I’m also going to see about paint gun settings.

Yes, two coats is typically recommend by most suppliers and seeing the aluminum through the first coat means it is too light of a coat, yet baffles me how you got such a thin coat while consuming so much material. Likely poor settings on the gun and losing it as overspray. Most epoxy primers have lots of pigments and will be completely opaque after the first coat. Wash primers like the SW, are different and will be much less opaque. I have never used Akzo products, so I suppose it is possibly very light on pigments and the first coat wasn't that light.

Larry
 
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I will def check the other options out. I want to do the inside fuse grey. Was thinking of using PPG I’ve heard it’s great quality too and cheaper than Azko.

I’ll check the spray gun and possibly
Use more reducer
 
Spray gun

Yea I thought so too ….. perhaps I was applying to much making sure everything was covered. I guess I could just stick with one light coat. Reason why I used 2 coats was because some aluminum was showing a bit… though I had to have everything totally “green(ed)” out.

I’m also going to see about paint gun settings.

A photo or two might help but a local builder familiar with spraying Akzo would help a lot. They would be able to help with gun setting and thickness.
 
I attached a few photos here of the sprayed skins and parts. Everything is like this....looks pretty standard to other pics I've seen.
I have a contact who works for Akzo Nobel and I will call him tomorrow to see what his says about the situation.

How do the other primers measure up to the Akzo green primer??
I do greatly appreciate all the assistance from other builders. It means a lot:)
 

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I am using Azko Nobel for my rv10 internal parts. I am just finishing up the elevator and already used an entire 2 gallon set of primer…. 1 set (2 gallons) primed HS, elevator, VS and rudder. What is the amount of primer I will most likely require for entire airframe. I hope it’s not too much. I thought this one set would go further than it did. I sprayed 2 light coats with the HF black widow HPE gun. Any support will be greatly appreciated.
Total weight is also on my mind as well as possible other options for fuse

Just for reference, measure your part with a micrometer after priming. You already know the thickness of the parts before priming. AKZO should be 1 to 1.3 mils when dry.

I think I’ll get my entire Emp primed along with the wing substructure and some of the wing skins with one “Kit” (2 gallons).

I’m still dialing in my technique as this is the first time ever using a spray gun setup on a project.
 
I appreciate the tips. I beleive I have my gun settings incorrectly. I beleive this also caused unnecessary overspray.

One thing I was thinking is the required or recommened amount of reducer for the Akzo? I beleive I mixed 7oz each base and curing agent (total 14oz) and added 2.5oz of thinner.
 
I
One thing I was thinking is the required or recommened amount of reducer for the Akzo? I beleive I mixed 7oz each base and curing agent (total 14oz) and added 2.5oz of thinner.

I would start with the datasheet from akzo and used their recommendations. Too much reducer gives a thinner coat and you want the coating thickness recommended by the designer in order to achieve best results. If it gets too thin, it won't do it's job effectively. Better to figure out how to get the desired coat thickness via gun adjustment and technique over heavy reducing and hosing it on.

Go watch some videos. It is NOT just gun adjustment. Those adjustments must be mated with a specific gun travel speed and gun distance, both of which must be very consistent over the spraying operation. Not holding the gun perpendicular to the panel will create excessive over spray also. Be aware that many data sheets list the tip pressure and not line pressure for HVLP, so be sure you are reading it correctly and adapting if necessary. Also be sure you are not using recommended pressures for compliant guns on your HVLP gun. I use 45 PSI on my compliant gun for clear, but that would create massive over spray if used on an HVLP.

Larry
 
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I did some modifications to my spray gun / patterns and issue is now resolved. I will not be going through that much primer anymore.
Pressure was to high and I was getting lots of extra air overspray:-(
 
I use Rustoleum self etching primer. It sprays very nicely.

I bought a brand from NAPA and absolutely hate it.
 
I use Rustoleum self etching primer. It sprays very nicely.

I bought a brand from NAPA and absolutely hate it.

My biggest gripe with spray can primers is the spray pattern. Even though the pattern of spray is a very small "fan" (it's really more of a round spot, not a fan) the overspray is pretty significant. I grab a can for small pieces or one-off things, but for anything of decent size, the cans just don't seem to go very far because half of the primer ends up in the air or on the surrounding bench. I do like Rustoleum the best (absolutely hated the Duplicolor I got - the fumes were horrendous), but after some experimentation I now just use their non-self etching primer. Since I scuff surfaces regardless of primer type, I figured I may as well save a few bucks per can.
 
It depends. The interior of the airplane is all P60G2. I still spray it but very seldom as the airplane is almost done. Nothing to prime inside. Cockpit interior was sprayed with SW JetFlex over P60G2 before assembly so rivets would show. Bare steel parts get Napa 7220. Rattle can. I prime nutplates too. Fiberglass is primed and painted with Kirker EnduroPrime (2K Epoxy) and UltraGlo (Single stage Urethane).
The entire exterior got Alodined. It will be vinyl wrapped.
Tons of photos and tips on my blog.

If I build another, P60G2 would be my choice again except for cockpit. I would spray Enduroprime as a primer/top coat. It's hard as nails and comes in White, Gray and Black. One paint. Save weight.

Why Enduro prime vs Eastwood epoxy primer which I've seen used more often by homebuilders if I wasn't going to put an additional layer of paint over it like Jetflex? Also, in your opinion, would a quart cover all the parts of a 14 forward fuselage area starting with the baggage compartment or is that more likely a 2 quart sized job? The interior will be covered by a Lemke interior kit so a generic gray primer finish is good enough for me in the areas exposed directly to sunlight after the interior kit is installed. If I can get a primer that's really easy to use, doesn't require PPE beyond a good respirator, and has decent UV and good wear and tear and is easy to mix and apply that's good enough for me.
 
Primer

Why Enduro prime vs Eastwood epoxy primer which I've seen used more often by homebuilders if I wasn't going to put an additional layer of paint over it like Jetflex? Also, in your opinion, would a quart cover all the parts of a 14 forward fuselage area starting with the baggage compartment or is that more likely a 2 quart sized job? The interior will be covered by a Lemke interior kit so a generic gray primer finish is good enough for me in the areas exposed directly to sunlight after the interior kit is installed. If I can get a primer that's really easy to use, doesn't require PPE beyond a good respirator, and has decent UV and good wear and tear and is easy to mix and apply that's good enough for me.

Kirker manufacturers Eastwood and Summit. At least that's what their Tech Support person told me. They actually answer the phone.
I think all three are good 2K epoxy primers either way.
A quart would be very close. I would buy the gallon and practice first. Minor difference in cost.
It's low VOC and no isocyanates but you still want a really good respirator or positive pressure system. 3M 60926 filters or a Hobby Air.
I can't comment on durability in an airplane but the wheels on my 4x4 (Suzuki Samurai) were sprayed with white several years ago and still look new. Colorado sun, heat and salty roads. I beat it up pretty hard.
I use a paint calculator. It's on my blog for download. Primer usually covers 2-3 ft² per coat. You can do some quick calculations and figure it. I would shoot at least two coats on any high wear areas. Three would be better. I thin about 15% with their slow (high temp) reducer for spraying.
E-mail if you need tips.
 
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You are referring to their EP-611? I called Kirker tech rep and unfortunately they put in zero UV inhibiter in any of their primer and really encouraged painting with a finish paint while the primer was still wet.

https://www.amazon.com/Kirker-Enduro-Primer-Gallon-Catalyst/dp/B09BG7TQ37?th=1

Kirker manufacturers Eastwood and Summit. At least that's what their Tech Support person told me. They actually answer the phone.
I think all three are good 2K epoxy primers either way.
A quart would be very close. I would buy the gallon and practice first. Minor difference in cost.
It's low VOC and no isocyanates but you still want a really good respirator or positive pressure system. 3M 60926 filters or a Hobby Air.
I can't comment on durability in an airplane but the wheels on my 4x4 (Suzuki Samurai) were sprayed with white several years ago and still look new. Colorado sun, heat and salty roads. I beat it up pretty hard.
I use a paint calculator. It's on my blog for download. Primer usually covers 2-3 ft² per coat. You can do some quick calculations and figure it. I would shoot at least two coats on any high wear areas. Three would be better. I thin about 15% with their slow (high temp) reducer for spraying.
E-mail if you need tips.
 
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Like airplane selection and configuration, it depends on what you want in a primer. Knowing these really narrows the selection.

Active corrosion protection? Like Boeing/Airbus - DoD?
Easy to apply.
Tough and scratch proof.
Cheap . . . low cost
Spray in basement or spray in a ventilated booth?
Equipment needed for application.
Resistant to acetone, nasty fluids?
Good shelf life
Good adhesion to substrate.

I have finally (when very near the end, and too late) decided on active protection and resistant to acetone/nasty fluids - it also is pretty tough. Akzo is the best overall, good color and can be used for an interior. Again, learned too late for my flying bird.
 
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I love the SEM Self Etching Primer (SEM 39683 Grey Self Etching Primer - 15.5 oz.) in rattle cans. It bonds tenaciously, and dries super fast. I can prime parts on one side, and turn them over after 5 minutes to spray on the other side. Can install parts 10 minutes later if necessary. If you're not in a coastal area, this should be more than adequate. Not cheap, but none of the good primers are. Cheaper if you buy in cases of 6.

Self-etching primers are not recommended as a primer for your final paint, so if you use this on exposed areas to be painted, you'll want to install an appropriate primer before you paint. I'm using it mainly for hidden, interior areas.
 
EnduroPrime

You are referring to their EP-611? I called Kirker tech rep and unfortunately they put in zero UV inhibiter in any of their primer and really encouraged painting with a finish paint while the primer was still wet.

https://www.amazon.com/Kirker-Enduro-Primer-Gallon-Catalyst/dp/B09BG7TQ37?th=1

Yep. That's the stuff.

And yes, I also knew about the UV thing. I doubt you can find any primer with UV inhibit. They aren't designed to be used that way. Let us know what you end up spraying.
 
I love the SEM Self Etching Primer (SEM 39683 Grey Self Etching Primer - 15.5 oz.) in rattle cans. It bonds tenaciously, and dries super fast. I can prime parts on one side, and turn them over after 5 minutes to spray on the other side. Can install parts 10 minutes later if necessary. If you're not in a coastal area, this should be more than adequate. Not cheap, but none of the good primers are. Cheaper if you buy in cases of 6.

Self-etching primers are not recommended as a primer for your final paint, so if you use this on exposed areas to be painted, you'll want to install an appropriate primer before you paint. I'm using it mainly for hidden, interior areas.

Ray,

Approx how many cans to prime interior parts and I assume not the interior skins. I will be building RV-12 and area is too small for some type of paint booth.

Thanks, Tom
 
Akzo Nobel 10P4-2NF

For stuff nobody will ever see once the airplane is complete, and for stuff that will be painted with a finish color someday, I use Akzo Nobel 10P4-2NF (Boeing green) 2-part epoxy primer that is advertised as corrosion and solvent resistant.

I have tried various prepping techniques. Scrubbing with a gray Scotch-Brite pad and Bon Ami followed by a thorough water rinse works, but you have to be careful about drying the part. Wiping down with acetone, scrubbing with a dry gray Scotch-Brite pad, and then wiping with acetone until the rag comes away clean also works and doesn't leave sneaky little water droplets. One advantage of the Bon Ami technique is you have lots of water on the part to use to inspect for water beading up, which is a sign you aren't done cleaning and scuffing yet.

I was not happy with one fairly popular and allegedly environmentally friendly product. I have had mixed results with alodine. Sometimes it almost seems to act like a primer repellent, which is the opposite of what one is led to expect.

I use a HF spray gun with a 1.3 mm tip.

The 10P4-2NF dries to the touch in 20-30 minutes at 70 deg. F., fully cures in about a day. (I live in a dry climate.) Once cured, over a properly prepped surface, dimpling doesn't damage it. Setting rivets doesn't damage it if you're careful. Wiping with MEK or acetone after it cures leaves a light green tinge on the rag but doesn't seem to otherwise bother the primer on the part. If you have to get it off an area of a part, a maroon Scotch-Brite pad soaked in MEK or acetone, combined with some elbow grease, work eventually.

It's not particularly cheap, but it's not the most expensive 2k primer out there either.
 
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