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Primer Dilemma

Magnumaviation

I'm New Here
OK, So I just ordered a 14 emp kit. Excited to start and join the rv club. My first problem....to prime or not to prime, that is the question?? If the answer is yes, what are the best options as far as products. Also, the "best" (considering clean up, application, ect...) systems for applying. Was thinking of trying to get primer into spray cans for easy use and cleanup. Any thoughts.... Thanks Alot
 
Congrats on getting started. You’re going to have a lot of fun. Take the time to look over the Primer section’s history in the forums; every conceivable question has been asked and answered there. It’s a really personal and contentious topic, so I’ll just sit here with my popcorn and watch the show. Good luck.
 
Eastwood Low VOC Direct to metal epoxy primer

I had excellent results with this product. Easy to mix and easy to spray even with a cheap Earlex HVLP spray system. I used PPE, exhausted ventilation and it had almost no smell. I mixed gray with white to get the color I wanted. Only down size is that the pot life (after activation) is short compared to other products - however it was plenty long for each spraying session. It just means you cant spray the same batch the next day. Another advantage for me is that these guys are 30 minutes away, so i can get materials as needed and no shipping.

Paint link:

https://www.eastwood.com/eastwood-gray-epoxy-primer-gallon.html

Sprayer link:

https://www.earlex.com/products/earlex-hv5500/

Just what I did - YMMV:)
 
I just order my emp as well. I am planning to prime as I am planning to fly to some beaches near me (KARS). Don't want to risk the salt corrosion.
 
PPE

I sprayed P60G2 and would probably do it again. Light and easy to apply.
Outside I've been using Kirker products. They are also sold under Eastwood and Summit. Same paints. EnduroPrime is a 2K Epoxy. UltraGlo is a Urethane Single Stage.
EnduroPrime is a really nice primer. If I do another, I'll shoot it as a single coat interior paint on parts that show. Comes in white, gray and black.
Whatever you decide, invest in PPE. Hobby Air for spray work and a 3M Mask with #60926 filters for static mixing and cleaning.
 
This is obviously a complicated subject, considering the significant amount of discussion here about it. Definitely read up.

Quickly: I chose to prime, as my RV-10 will spend a lot of time visiting the beach.

1. Priming will add time, expense, complexity, required tooling, and space to your project. Until you get comfortable and quick with your paint rig, you will add quite a bit of time and eat up days to prep and prime parts. If you don't have a dedicated paint booth or space, you will spend a lot of time setting up and tearing down. I made the choice that it's worth it for me, but consider what you think you'll really need.

2. You will find yourself jumping around in the plans a bit in order to get enough parts to make a painting session worthwhile, while not gathering so many that you have to make multiple batches of paint. The surface prep that needs to be done to get a good paint-metal bond takes a lot of time right before the paint session, so consider that in your planning as well.

3. I am using the Sherwin Williams strontium chromate primer (CM0724400) in the bright yellow color. I chose it for its corrosion protection properties, and the color is bright enough that it should make inspections easier. The downside is that it is pretty toxic and needs to be handled with respect. That means I use a half face respirator with P100 filters and VOC cartridges under a supplied air hood (Breathecool II) when painting. I use the half face/VOC cartridges alone when mixing the paint and handling cleanup. My paint booth is well ventilated to the outside and I still get enough VOC in the other parts of the building that I generally paint as the last item of the day so I can leave it all to air out overnight.

4. For priming I am using a decent HVLP gun from Harbor Freight (the mid-to-upper grade one they sell) and it works well enough for internal part priming. I use the DeVilbiss DeKups system and it really helps with prep and cleanup of the gun. The disposable cups and filters make it really easy to mix paint and clean the gun up. For spot work I use the little Preval sprayers. I have a laboratory magnetic stir bar hot plate that I use for mixing the paint (heat turned off)--the stir bar gets filtered out in the DeKups system and I just retrieve it at the end of the paint cup.

5. Use a coalescing filter on the air supply, and dedicate separate hoses for painting only (you don't want oil or water in them). I also have an auto-blowdown on my compressor to keep the moisture down, and the coalescing filter removes water droplets as well as oil. I use dessicator filters available cheap from Harbor Freight as a final drying step right at the regulator before the hose to my gun. One has lasted me quite a while (all of my painting sessions so far--nearly 2 gallons of primer/adduct mix) and still has no color change in the indicating beads.

6. If you are painting at home and don't have a detached garage or shop, think carefully about how you are going to keep the fumes and paint dust out of the rest of the house.


Just some thoughts. There are very good reasons to prime, but be aware it will probably add a lot of complexity to your building process.
 
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I started my -14A empennage a couple months ago and faced the same question initially. I decided to go ahead with priming and went with the Stuart Systems EkoPrime. It's easy to apply, quick to dry and easy to clean up, which means it's not a big deal to paint just a few parts as you go. Considerably easier than 2k epoxies.

You do need to carefully prep parts before painting and that does add considerable time. Only thing I'd do differently is to go with a darker color. I went Smoke Grey and while it looks very good when done, it is difficult to tell when you have adequate coverage as it blends in easily with the aluminum.
 
This is obviously a complicated subject, considering the significant amount of discussion here about it. Definitely read up.

Quickly: I chose to prime, as my RV-10 will spend a lot of time visiting the beach.

1. Priming will add time, expense, complexity, required tooling, and space to your project. Until you get comfortable and quick with your paint rig, you will add quite a bit of time and eat up days to prep and prime parts. If you don't have a dedicated paint booth or space, you will spend a lot of time setting up and tearing down. I made the choice that it's worth it for me, but consider what you think you'll really need.

2. You will find yourself jumping around in the plans a bit in order to get enough parts to make a painting session worthwhile, while not gathering so many that you have to make multiple batches of paint. The surface prep that needs to be done to get a good paint-metal bond takes a lot of time right before the paint session, so consider that in your planning as well.

3. I am using the Sherwin Williams strontium chromate primer (CM0724400) in the bright yellow color. I chose it for its corrosion protection properties, and the color is bright enough that it should make inspections easier. The downside is that it is pretty toxic and needs to be handled with respect. That means I use a half face respirator with P100 filters and VOC cartridges under a supplied air hood (Breathecool II) when painting. I use the half face/VOC cartridges alone when mixing the paint and handling cleanup. My paint booth is well ventilated to the outside and I still get enough VOC in the other parts of the building that I generally paint as the last item of the day so I can leave it all to air out overnight.

4. For priming I am using a decent HVLP gun from Harbor Freight (the mid-to-upper grade one they sell) and it works well enough for internal part priming. I use the DeVilbiss DeKups system and it really helps with prep and cleanup of the gun. The disposable cups and filters make it really easy to mix paint and clean the gun up. For spot work I use the little Preval sprayers. I have a laboratory magnetic stir bar hot plate that I use for mixing the paint (heat turned off)--the stir bar gets filtered out in the DeKups system and I just retrieve it at the end of the paint cup.

5. Use a coalescing filter on the air supply, and dedicate separate hoses for painting only (you don't want oil or water in them). I also have an auto-blowdown on my compressor to keep the moisture down, and the coalescing filter removes water droplets as well as oil. I use dessicator filters available cheap from Harbor Freight as a final drying step right at the regulator before the hose to my gun. One has lasted me quite a while (all of my painting sessions so far--nearly 2 gallons of primer/adduct mix) and still has no color change in the indicating beads.

6. If you are painting at home and don't have a detached garage or shop, think carefully about how you are going to keep the fumes and paint dust out of the rest of the house.


Just some thoughts. There are very good reasons to prime, but be aware it will probably add a lot of complexity to your building process.

Thanks for the great info and response. Trust me, those thoughts have been bouncing around in my head!
 
My advice about priming is this: Make the decision for yourself. Don’t let anyone else talk you into priming. It adds a lot of tedious work to the build. If you prime, there will be times when you curse whoever talked you into it. You will end up happy at the end, but you could lose some friends along the way.

For what it’s worth, I chose to prime with Stewart Systems EkoPrime and I am very happy with the results. Even if I sometimes say bad things about the friend who talked me into priming. :)
 
My advice about priming is this: Make the decision for yourself. Don’t let anyone else talk you into priming. It adds a lot of tedious work to the build. If you prime, there will be times when you curse whoever talked you into it. You will end up happy at the end, but you could lose some friends along the way.

For what it’s worth, I chose to prime with Stewart Systems EkoPrime and I am very happy with the results. Even if I sometimes say bad things about the friend who talked me into priming. :)

It almost seem you are trying to talking him into it :)

I will just share my experience and you can decide on your own. I did not prime on my first build but primed on the second build using the Akzo primer. The process does add some additional effort but it was not a drastic effort. The primer goes on really easy and it is super durable.

If I build again, I will prime again. It does give me that ease of mind that the plane will far less likely be subject to corrosion but it does add a bit of weight to the build.
 
Priming

Feel free to read my Paint page on my blog. I didn't think it was all that much more work to prime. Certainly less work than Alodine. More work than bare aluminum.
Like the ma said. You decide.
 
I'm 609 hours into my build (doing my fuel tanks now), and I have 68 hours of prep / priming time.

So i think you can say 10% more time for priming as an estimate.

My process is using Stewart Systems EkoPoxy - which involves a clean with their cleaner, then an acid etch and mechanical scrub, then drying and 2 part spraying.
 
I have a 68 year old Cessna 195. No interior primer and no corrosion. It has lived most of its life in upstate NY, 15 years in Alaska, 10 years in Tulsa and the last 6 with me. I spray it with ACF-50 every year and fly it often.

If you decide to not prime your aircraft interior parts, it will still out live you. Even if you take it to visit the beach from time to time.
 
EkoPrime

Another +1 for Stewart systems EkoPrme. The only drawback is that it leaves a yellow dust in every nook and cranny in the garage.
 
I'm very early into the build, and spent considerable time pondering and stressing about the decision to prime. I spoke with my EAA chapter members who had previously built without prime, and many years later their aircraft look like new.

Then I contacted a couple of paint shops (aircraft). I explained that I was pondering priming using a 2-part epoxy. As painters, they loved that idea and felt that it would provide the most protection (albeit add time, weight and money).

I initially settled in the middle of the road with the Sherwin Williams wash prime that Van's uses. I figured that if it's good enough for Vans, it's good enough for me. Their test piece that they reference didn't hurt the decision.

After priming the vertical stabilizer and rudder stiffeners/shear clips, I realized a couple of things... I am not a painter. Like, I would have been better off with fingerpaints. While priming did add a bit of extra time, the problem that I had is a lack of a paint booth. I'm sharing the workshop/hangar with a friend who has a beautiful Beech A36 that he's pretty fond of. Chicago weather isn't conducive to painting outside, especially in the winter.

After beginning with the wash prime, I've elected to forgo the primer on my build. If I had a spray booth, I'd probably sling some wash prime on just for the peace of mind. But in my situation/location, I'm confident that the aircraft will outlive at least me, and probably my son.

But as others have said, don't let anyone talk you into or out of priming. It's your own decision. Personally, I don't think you can go wrong with priming if you have the capabilities and facilities to do so. I have neither, and am fine motoring forward without.
 
My "paint booth" setup. I cut down the Van's empennage crate. I figure this is why it's so big. I attached a couple 6" vents to the bottom and have those running to a 6" forced air duct fan. The exhaust passes through a filter box I made using a cheap replaceable furnace filter and it vented to outside the garage door. When it's running, it does a decent job of keeping everything contained. I also spray wearing a respirator.

The tent itself is a portable paint booth from Lee Valley.

https://www.leevalley.com/en-ca/shop/tools/supplies/finishing/76184-portable-spray-shelters

You can pick one up when you buy your Mix Mates:

https://www.leevalley.com/en-ca/shop/tools/supplies/finishing/75038-mixing-mate-for-paint-and-finish
 

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Alcad 2024-T3 is fine without being primed. The biggest advantage to priming internally is resale.
If it's not primed, the prospective purchaser has a bargaining tool.
 
Paint booth

I primed at 7,500' throuh the dead of Winter with no paint booth. Not saying you should or shouldn't prime, but a paint booth is optional. Just offering alternate options.
I set everything up, run parts outside, spray, run back in. On super cold days, like below freezing, I fabricated a temp booth using old shower curtains. 3/4" conduit sections were suspended from the garage frames. Very handy fir all sorts of stuff. Curtain booth sets up in minutes. A 4" wall dryer vent is connected to a hose and bildge blower for exhaust. Wife gets new shower curtains so she's happy!
All my interior and exterior paints were also sprayed this way. Either outside or in the shower curtain booth.

Ask asyone who's seen my airplane if they can tell.
 
My "paint booth" setup. I cut down the Van's empennage crate. I figure this is why it's so big. I attached a couple 6" vents to the bottom and have those running to a 6" forced air duct fan. The exhaust passes through a filter box I made using a cheap replaceable furnace filter and it vented to outside the garage door. When it's running, it does a decent job of keeping everything contained. I also spray wearing a respirator.

The tent itself is a portable paint booth from Lee Valley.

https://www.leevalley.com/en-ca/shop/tools/supplies/finishing/76184-portable-spray-shelters

You can pick one up when you buy your Mix Mates:

https://www.leevalley.com/en-ca/shop/tools/supplies/finishing/75038-mixing-mate-for-paint-and-finish

Would you have a close up picture of your crate showing how you rigged the fan and vents?

Thanks
 
Would you have a close up picture of your crate showing how you rigged the fan and vents?

Thanks

Unfortunately, I took it apart this week in order to do some electrical work in the shop. Here is a photo of the exhaust system though. Basically, I cut out two 4" holes about 18" apart in the bottom of the crate. I cut two pieces of 4" flexible dryer ductwork about 2' long and placed them in the crate holes. On the other end, I connected them to a 4" Tee and then to a 4" to 6" coupler. From the coupler, I go into a homemade filter box (basically, a 8" cardboard box with a slot in the top to accept cut down furnace filters). From this, the duct goes to the 6" booster fan and out through more 6" flexible duct. The booster fan runs on 120V AC, so plug it in and away you go.

It does pull air from the crate, but is not creating too much suction. I have found primer dust in the filter, so I know it's working. I haven't seen a speck of primer outside my "paint booth". I also put a portable heater in the booth to keep things toasty. So far, I'm pleased with this setup.
 

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Here is the booth I have now. It’s 6mil poly strung from metal conduit. I just used document clips to hold it up there as tape won’t really stick (even the tape for poly isn’t that good).

I built a little frame for three box fans that I put $2 furnace filters on and put in the open garage doorway and that blows all the fumes outside and collects a lot of the overspray.

I’m using AKZO, so I don’t want the fumes going inside, and I want to limit dust in the garage as much as possible.

Prior to this I had a 2x4 framed booth. It was awesome, but took up too much room in the third stall.

I eventually just put LED strip lights over the area for lights ($10 at menards)
 

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