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My Choice Regarding Priming

M

milhouse1312

I'm New Here
Despite the risk of reigniting the war, I figured I'd consolidate a few thoughts I've had recently as I'm beginning to (re-)start my RV-14A project.

Prior to my laser cut parts replacement (and even after), I spent a TON of time trying to figure out what process to use to prime. I spent so much time, in fact, that I've actually decided to not prime... at least for now. Here's why:
  1. Priming is extremely time consuming and can add significant costs to the build. I never made it far in my kit before I halted due to the LCP issue, but I'd say between 1/3 and 1/2 the time I spent was on priming or prepping for priming. (i.e. scuffing parts, then rinsing, cleaning and degreasing, drying and finally priming, then waiting a day for the primer to cure.) It's a time sink. I'd estimate it could add 500 hours to the project overall. Between that and avoiding nasty chemicals, any hit to resale value (if any) is counterbalanced by the significant reduction in time, money and potential health consequences. Time is money. Materials cost money. Health is priceless.
  2. Priming will add weight. I plan on flying the plane primarily as a cross country machine. When loading up the airplane including the baggage area, the extra weight might adversely affect weight and balance, especially if that extra weight is way aft in the empennage I plan on restarting soon.
  3. I don't know where life will take me, but I currently don't live in an area with corrision problems. My local flight school has a 182 that's been sitting on their ramp in the elements for decades. Their mechanic has told me that airplane doesn't have any corrosion issues. He does apply ACF50 as a preventatitve measure to their unprimed airplanes every few years. Takes two people an afternoon. I've been there a while and have never seen the 'weeping' people on here complain about. Even if I end up in a corrosion-prone area, I will hangar the plane unlike my local school.
  4. I imagine I'll be done flying 30 or 35 years after this project is completed, and would almost certainly give up any aerobatics long before that. That means that if problems do start occuring in a decade or two, I'll still have an overbuilt airplane for the cross country mission.
  5. If corrosion becomes an issue, Corrosion X or ACF50 are options. There may even be a better product in the future. If it becomes a massive problem... well... I built it once, I suppose I can rebuild or build/replace major assemblies again. After all, I likely saved 500 hours the first time around.
  6. Here's the kicker: many builders who have primed their airplanes say they wouldn't prime their next airplane.
Seriously, this subject has totally stalled my build. I received LCP parts replacement a few months ago and haven't restarted, largely due to this issue. I've commited many hours to trying to figure out how to do this properly and efficiently. Now that I'm sick of being stuck in analysis paralysis, I've decided to build now and solve tomorrow's problems tomorrow. I'll scuff and rattle can the stuff that isn't alcald and leave the rest alone. FIgured I'd share this to help the next builders who get stalled over this issue like I did.
 
Your choice of course but I'm curious why bother to rattle can the non-alclad stuff, given you're not going to prime the alclad? The unprotected edges of the alclad alloy (i.e. every edge and hole) has a higher risk of corrosion than the 6061 alloy.
 
Priming, like most things, can be as hard or as easy as you make it.
Over this side of the Atlantic we have to prime the metal. Some people go to great lengths, others scuff and spray with rattle can chromate.
It’s doesn’t have to take hours and hours. Don’t over think it.
 
milhouse1312 said:
Despite the risk of reigniting the war, I figured I'd consolidate a few thoughts I've had recently as I'm beginning to (re-)start my RV-14A project.

Prior to my laser cut parts replacement (and even after), I spent a TON of time trying to figure out what process to use to prime. I spent so much time, in fact, that I've actually decided to not prime... at least for now. Here's why:
  1. Priming is extremely time consuming and can add significant costs to the build. I never made it far in my kit before I halted due to the LCP issue, but I'd say between 1/3 and 1/2 the time I spent was on priming or prepping for priming. (i.e. scuffing parts, then rinsing, cleaning and degreasing, drying and finally priming, then waiting a day for the primer to cure.) It's a time sink. I'd estimate it could add 500 hours to the project overall. Between that and avoiding nasty chemicals, any hit to resale value (if any) is counterbalanced by the significant reduction in time, money and potential health consequences. Time is money. Materials cost money. Health is priceless.
  2. Priming will add weight. I plan on flying the plane primarily as a cross country machine. When loading up the airplane including the baggage area, the extra weight might adversely affect weight and balance, especially if that extra weight is way aft in the empennage I plan on restarting soon.
  3. I don't know where life will take me, but I currently don't live in an area with corrision problems. My local flight school has a 182 that's been sitting on their ramp in the elements for decades. Their mechanic has told me that airplane doesn't have any corrosion issues. He does apply ACF50 as a preventatitve measure to their unprimed airplanes every few years. Takes two people an afternoon. I've been there a while and have never seen the 'weeping' people on here complain about. Even if I end up in a corrosion-prone area, I will hangar the plane unlike my local school.
  4. I imagine I'll be done flying 30 or 35 years after this project is completed, and would almost certainly give up any aerobatics long before that. That means that if problems do start occuring in a decade or two, I'll still have an overbuilt airplane for the cross country mission.
  5. If corrosion becomes an issue, Corrosion X or ACF50 are options. There may even be a better product in the future. If it becomes a massive problem... well... I built it once, I suppose I can rebuild or build/replace major assemblies again. After all, I likely saved 500 hours the first time around.
  6. Here's the kicker: many builders who have primed their airplanes say they wouldn't prime their next airplane.
Seriously, this subject has totally stalled my build. I received LCP parts replacement a few months ago and haven't restarted, largely due to this issue. I've commited many hours to trying to figure out how to do this properly and efficiently. Now that I'm sick of being stuck in analysis paralysis, I've decided to build now and solve tomorrow's problems tomorrow. I'll scuff and rattle can the stuff that isn't alcald and leave the rest alone. FIgured I'd share this to help the next builders who get stalled over this issue like I did.
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My choice was to alodine everything that could fit into custom trays that were deep enough for ribs, longerons, and pretty much every small part. Since alumaprep takes care of the scuffing and alodine takes care of the priming you end up with mated areas very well protected that otherwise might not have been since the part is submerged. Every dimpled hole, every wrinkled rib. And in theory, zero weight gain since you’ve lost a tiny bit of material during the alumaprep bath and gained only microns thickness during the alodine. Best of all the colour is gorgeous. This wasn’t that expensive and didn’t take much time. The prep included identifying the parts with ss washer coupons wired to the part with part numbers etched on. (On, maybe that took a bit of time, but none of this amounted to 500 hours).

And yes, health is precious, so when I did the actual alodine and alumaprep it looked like an episode of breaking bad. Floor covered with plastic in case of spills. 3m suite, and a dual canister breather and gloves. Did dozens of parts at a time.

AND, if you want to save even more weight then you polish as I did. No paint weight.
But just to clarify, you don’t wait until corrosion becomes a problem. You spray ACF50 when new and reapply every couple years as the flight school does. I bought the sprayer and applicator kit for ACF 50. Do this during one of the annuals when all the panels would have been off regardless and then just minutes to apply the spray.

Sorry to hear how the subject stalled you. I didn’t get hit with the laser cut parts but I can certainly understand the frustration and time lost. For me, like most I’m sure, there were lots of other challenges. 7 years is a long time for any project. Take time to enjoy the quality of your results at every phase and be assured it’s worth it. (Flying since July 2022).

Michael B
 
Another data point although I also alodined a lot of parts. If I could find a shop willing to alodine large stuff, I would have done more.
Anyway, P60G2 weighs almost nothing. I weighed lots of parts before and after to try and estimate weight gain. It was so little, I quit trying. Easy to apply. Dries almost instantly.
 
milhouse1312 said:
1-Priming is extremely time consuming and can add significant costs to the build.
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After priming all the parts in the first three kits, I've come to the opposite conclusion.

When I have a large batch of parts that are trimmed, deburred, dimpled and ready to prime, it generally takes me 60-90 minutes to paint that batch of parts. That includes scuffing the parts with PreKote, rinsing, drying and hanging them in the paint booth, mixing the paint, spraying the parts and clean up. I probably spend 1 hour priming for every 75-100 hours of parts prep. For me, that's pretty insignificant. I guess for others that's extremely time consuming.

Yes, Akzo primer isn't cheap at $400 for 2 gallons but compared to the $300,000 that it will cost to build my airplane, it's pocket change and cheap insurance.

As for weight, if you switch from a lead acid battery to LiFePO4, you'll save more weight than what the primer weighs. I can't speak to other primers but 95% of the Akzo primer I spray on evaporates when dry. It leaves a very thin film that weighs almost nothing.

Just want to show a different perspective from somebody who has actually primed something.
 
When I have a large batch of parts that are trimmed, deburred, dimpled and ready to prime, it generally takes me 60-90 minutes to paint that batch of parts. That includes scuffing the parts with PreKote, rinsing, drying and hanging them in the paint booth, mixing the paint, spraying the parts and clean up. I probably spend 1 hour priming for every 75-100 hours of parts prep. For me, that's pretty insignificant. I guess for others that's extremely time consuming.
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I think it all depends on the method. I do not claim to be an experienced builder. You do make yours sound easy and after years I'm sure your method has gotten quite efficient, but spending 1% of your time priming sounds intriguingly low.

Perhaps you could tell me where I'm wasting time. Here was my method:
  1. Scuff with maroon pads after removing tape and residue. That was scrubbing by hand at first until I discovered the scrubbing wheels that can attach to a die grinder. That sped things up some, but could only be used on certain surfaces.
  2. Rinse with water and then wipe down with alcohol and/or an off the shelf degreaser.
  3. Spray a self-etching rattle can primer on all the parts, usually applying two very light coats
  4. Then wait 24 hours to be sure that cures.
When you add that all up, it ends up being a lot of time. The RV-14 prep work is mostly done prior to shipping the kit. Sure there are some parts that require trimming, etc, but it's mostly a matter of deburring edges as necessary, dimpling and riveting together. I'd imagine its a much smaller percentage of total build time on older kits that require more prep work.
 
milhouse1312 said:
I think it all depends on the method. I do not claim to be an experienced builder. You do make yours sound easy and after years I'm sure your method has gotten quite efficient, but spending 1% of your time priming sounds intriguingly low.

Perhaps you could tell me where I'm wasting time. Here was my method:
  1. Scuff with maroon pads after removing tape and residue. That was scrubbing by hand at first until I discovered the scrubbing wheels that can attach to a die grinder. That sped things up some, but could only be used on certain surfaces.
  2. Rinse with water and then wipe down with alcohol and/or an off the shelf degreaser.
  3. Spray a self-etching rattle can primer on all the parts, usually applying two very light coats
  4. Then wait 24 hours to be sure that cures.
When you add that all up, it ends up being a lot of time. The RV-14 prep work is mostly done prior to shipping the kit. Sure there are some parts that require trimming, etc, but it's mostly a matter of deburring edges as necessary, dimpling and riveting together. I'd imagine it’s a much smaller percentage of total build time on older kits that require more prep work.
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I have a slightly different process—spray with EkoEtch, scrub with red pad, rinse thoroughly, dry for an hour or so, prime with EkoPrime. But the key, as Brian mentioned, is the same. That is to do a large batch of parts at once—basically every part you need for whatever part of the plane you’re working on. If you prime each time you finish working on a few parts then priming will take a lot of time.

I usually finish the day with priming, which means the parts will have cured enough by the time I start working the next day. But if I’m careful, I can work with the parts an hour after priming.
 
Here's a different method. Deburing & dimpling are done first. Those steps have to be done anyway so they don't count against the time clock.
Flat parts like skins and such can be scuffed really fast with a maroon pad on a random orbital. Other parts can be scuffed and washed simultaneously by washing with Bon Ami and a maroon pad. After rinse, they are hydrophillic. Dry and paint.
To be fair, it does take some time to prep, mix, paint and clean. It sounds like that's the issue. A can of SEM rattle can will speed that up.
 
milhouse1312 said:
Perhaps you could tell me where I'm wasting time.
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After scuffing the parts with Scotchbrite pads and PreKote (lightly and by hand), I just rinse them with water. I don't use alcohol and degreaser afterwards. I also don't need to apply two coats with Akzo. A spray gun covers more surface area than a rattle can so that alone saves a little more time during application.

As for the parts prep prior to priming, there is a LOT of work in prepping the parts. Yes, the RV-14 kit is much more complete than the RV-4 was. But, almost every part needs to be trimmed, deburred, dimpled, etc. That takes way, WAY more time than priming.

I will say the first time I primed it took much longer. I had never used a spray gun. Never used a bunny suit and mask. Never mixed a two part epoxy paint. It was very intimidating. Probably took twice or three times as long as it did the second time. Now it's a non-event. I was also really concerned about whether or not I was applying the primer correctly. What I've learned is Akzo is extremely forgiving for poor technique.
 
Ben Ellis said:
...That is to do a large batch of parts at once—basically every part you need for whatever part of the plane you’re working on. If you prime each time you finish working on a few parts then priming will take a lot of time.

I usually finish the day with priming, which means the parts will have cured enough by the time I start working the next day.
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Bingo!
 
It's definitely frustrating when decisions stall progress. I think most people have been there at some point. The priming topic is ripe for a war because each approach can easily be justified if you look at extreme examples, which to me means it's likely that there is no actual "bad" decision. Glad you've made your decision and can move on!

Just as a data point from my experience: I live in a corrosion area, and I've primed virtually everything. Like you've obviously heard from others though, on my next build, that will not be the case. I'll still prime, but just mating surfaces with high quality, self etch rattle can primer. That being said, I haven't found that priming all surfaces has taken nearly the amount of time that you've estimated. Aside from a few remaining pieces, I'm done with everything that needs to be primed on my slow build. I haven't tracked time, but I just went and looked at the number of priming sessions I did, and I'd say it took maybe 75 hours or so to do absolutely everything.

My typical method has been to do a quick scuff with scotchbrite (I use a pad on my random orbit sander for large surfaces), clean with acetone, then spray with Ekoprime. The Ekoprime alone saves time since it is sprayed right out of the can with no catalyst wait time. Clean up is also a breeze. My process evolved over time - when I first started, I'd acid etch along with the manual scuff, rinse, dry, etc. After experimenting to test primer adhesion, I found that it was way more effort and time than I needed to spend. Especially for internal parts that will never get touched again, I even found that a manual scuff was, practically speaking, more than was actually necessary for adequate adhesion (I do still manual scuff, but just pointing out that for parts that will never see the light of day, my tests showed the Ekoprime stuck plenty good even with no etch/scuff step). I have a post somewhere that shows the differences in adhesion between different methods, including no scuff at all. I usually do any dimpling after priming. That makes scuffing way less painful. I've had zero issues dimpling the primer.

I only primed in large batches. I wouldn't prime parts until I had reached a point where I had done the initial fit on as much as I could and absolutely had to rivet things together to move on. In a few hours of prep and spraying, I could finish priming enough parts to last me a long time. I just use rattle can primer for the random small parts I run into that I need when I don't have any other parts to prime. For some pieces, I even primed them before I had touched them for the build, just to include them in a big batch (like skins - primed many of them a year before I touched them, then just did minor touch ups by hand to fix any scratches that occurred during build).

I suppose if you're counting 24 hours of cure time in your estimate, then you could hit many more hours, but I just move on to other things when I'm waiting for primer to dry, so I rarely stopped work just to wait for primer.

This isn't to try to change your mind at all. I just wanted to point out that I think your time savings is probably excessive, if that's a big deciding factor for you.
 
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skelrad said:
I wouldn't prime parts until I had reached a point where I had done the initial fit on as much as I could and absolutely had to rivet things together to move on.
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Exactly.

I'm not trying to change anybody's mind either. I just find a lot of misinformation here regarding priming and worry that new builders might be led down the wrong path. I researched priming for weeks before I started building. It has turned out to be a huge nothing-burger for me. I spend WAAAAAAAAAY more time researching all the things that aren't included in the plans.
 
bertschb said:
Exactly.

I'm not trying to change anybody's mind either. I just find a lot of misinformation here regarding priming and worry that new builders might be led down the wrong path. I researched priming for weeks before I started building. It has turned out to be a huge nothing-burger for me. I spend WAAAAAAAAAY more time researching all the things that aren't included in the plans.
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I'm not sure what people believe about Alclad material, but one thing to keep in mind, is that none of the edges of the material are clad with pure aluminum....only the face of the sheet. If you've drilled it, cut it, scratched it, or even de-burred it...you've removed most, if not all of the cladding.

Since most aluminum corrosion ( galvanic or physical) begins at the edges due to capillary action, I'm not sure it's sound to justify not doing it at all, due to excessive time concerns.

There are numerous manufacturers of Self Etching Primers, in the $12-$20 a can range that will do a very satisfactory job on all seam lines...basically anywhere you drill a hole, or cut an edge...and to apply them takes maybe a minute, inclusive of a light acetone wipe, prior to spray.


It doesn't have to be a fancy job, but it's probably a smart investment of a few hours, over the course of the project.

I am not suggesting that for the actual paint job, to use rattle can product. I am simply saying that for seams with cut edges, drilled holes etc...it's quick, cheap insurance for minimal cost and effort. When you do your paint...time spent to properly prep, prime and paint will be worth every minute.

I have also painted the interiors of many structures with just an acetone wipe and sprayed self etching primer, like inside of fuselage and it saves a lot of time over alodine/etch protocols and have been happy with the results.




Steve
 
+1 for eko-etch/eko-prime from Stewart Systems, very easy to use and little waste as unused primer can be returned to the can. Cleans up with water, and no catalyst. It also dries very durable, I have had no issues with it. Sticks super well with the proper acid etch.

A good peice of advice I was given was to build as much as possible, then when you cant go any farther without riveting, do a batch of primer. I think my record was over 100 peices in batch, about an afternoons work (with two of us).

Don't rule out priming, just dont over think it, and use what is easiest.
 
For what it's worth, possibly my biggest issue with it is the scuffing/cleaning. By far my least favorite part.

I was tempted for a while to not bother with scuffing at all and use a self etching primer. Had an unscuffed test coupon showing nearly as perfect adhesion as the "properly" scuffed, water-break-test-approved side. Mild scuffing had identical results as a 'perfect' sample. And I learned really quick not to wait to prime until after dimpling... Just rips up the pads and creates frustration.

So the other issue: there is no "right" way as far as can tell. Pretty sure you can ask 5 people how to prime an airplane and get 8 different answers. It's a dang, never-ending rabbit hole, and I've learned you just gotta make a decision and go with it. I suppose that's why I found the "Primer" tag listed under the "never ending debates" section. haha.
 
milhouse1312 said:
For what it's worth, possibly my biggest issue with it is the scuffing/cleaning. By far my least favorite part.

I was tempted for a while to not bother with scuffing at all and use a self etching primer. Had an unscuffed test coupon showing nearly as perfect adhesion as the "properly" scuffed, water-break-test-approved side. Mild scuffing had identical results as a 'perfect' sample. And I learned really quick not to wait to prime until after dimpling... Just rips up the pads and creates frustration.

So the other issue: there is no "right" way as far as can tell. Pretty sure you can ask 5 people how to prime an airplane and get 8 different answers. It's a dang, never-ending rabbit hole, and I've learned you just gotta make a decision and go with it. I suppose that's why I found the "Primer" tag listed under the "never ending debates" section. haha.
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One thing I've learned is that people try to adopt a Commercial Paint facility type approach....Anything you do will be better than nothing...My airplanes don't live outside. They go outside to fly and camp and then back in the hangar....I think nothing would probably be fine mostly....with self etch primers, you can just spray after a cleaning wipe. Get a few rattle cans of Self Etching primer and go forward!!!

is it 100%....probably not...but I've flown through rain at 180 mph many times and never yet had paint peel....good enough is probably good enough for everything but the final paint job on the exterior.
 
milhouse1312 said:
For what it's worth, possibly my biggest issue with it is the scuffing/cleaning. By far my least favorite part.

I was tempted for a while to not bother with scuffing at all and use a self etching primer. Had an unscuffed test coupon showing nearly as perfect adhesion as the "properly" scuffed, water-break-test-approved side. Mild scuffing had identical results as a 'perfect' sample. And I learned really quick not to wait to prime until after dimpling... Just rips up the pads and creates frustration.

So the other issue: there is no "right" way as far as can tell. Pretty sure you can ask 5 people how to prime an airplane and get 8 different answers. It's a dang, never-ending rabbit hole, and I've learned you just gotta make a decision and go with it. I suppose that's why I found the "Primer" tag listed under the "never ending debates" section. haha.
Click to expand...

In my opinion you should be ignoring opinions. Primers and paints are applied as part of a system and the manufacturers outline proper preparation and application. As to primers, many should not be applied on their own without a final coat. Some are not at all meant as anti-corrosion coatings so if the intent is to be protecting internal surfaces and mating surfaces choose somethings specifically meant to be used on its own. Alodine is a conversion “coating”. Chromate and phosphate coatings (many if not all) are also meant to protect on their own. SEM makes spray bombs that are pretty good if you want to avoid the bunny suit.
 
milhouse1312 said:
I think it all depends on the method. I do not claim to be an experienced builder. You do make yours sound easy and after years I'm sure your method has gotten quite efficient, but spending 1% of your time priming sounds intriguingly low.

Perhaps you could tell me where I'm wasting time. Here was my method:
  1. Scuff with maroon pads after removing tape and residue. That was scrubbing by hand at first until I discovered the scrubbing wheels that can attach to a die grinder. That sped things up some, but could only be used on certain surfaces.
  2. Rinse with water and then wipe down with alcohol and/or an off the shelf degreaser.
  3. Spray a self-etching rattle can primer on all the parts, usually applying two very light coats
  4. Then wait 24 hours to be sure that cures.
When you add that all up, it ends up being a lot of time. The RV-14 prep work is mostly done prior to shipping the kit. Sure there are some parts that require trimming, etc, but it's mostly a matter of deburring edges as necessary, dimpling and riveting together. I'd imagine its a much smaller percentage of total build time on older kits that require more prep work.
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You are over thinking it. Think of building in a production line. Prep all your parts in one step after you finished your inventory. Instead of doing it piecemeal, do the entire wing kit, or fuselage kit, or etc. If you prime only the few parts before assembly it then will take forever. I alodine and primed my parts before dimpling, fittings, or even know what the parts do. In the end, they all get alodine + prime so why wait. After all the parts are alodine and primed, you don't have to worry about priming for the next few years as you slow build. I am sure the primer has cured by then. For each of my kit, it only take me a few weeks working on the weekends to alodine and to etched prime at the metal joints. Find the most efficient process to build your kit instead of only following the instructions in the page as you get to it.
 
One more thing worth mentioning ( I'm a "prime 100% guy), that we do in heavy aircraft repair, and I did on my -4. Most immediately think of spray equipment, mess , overspray, clean-up associated with spraying. I applied all my skin inner surface primer with a foam cabinet roller, and I challenge anyone to see the difference between sprayed/rolled. I also keep stock of the chip bristle throw away brushes for doing small one off parts or even long stringer extrusions. I also use only Akzo or similar 2 part fluid resistant primers for their robust durability and peel resistance even if subjected to oils and fuel. . Even if mixed, I have a small refrigerator I toss paints and proseal mixes into, and can use it for several days before it cures. It really doesn't slow the build to the level mentioned, and if you "overthin" the product, it adds negligible weight. Dont even think about external prime until final paint , as the primer/paint process needs to be done all at once for best results.
 
fixnflyguy said:
One more thing worth mentioning ( I'm a "prime 100% guy), that we do in heavy aircraft repair, and I did on my -4. Most immediately think of spray equipment, mess , overspray, clean-up associated with spraying. I applied all my skin inner surface primer with a foam cabinet roller, and I challenge anyone to see the difference between sprayed/rolled. I also keep stock of the chip bristle throw away brushes for doing small one off parts or even long stringer extrusions. I also use only Akzo or similar 2 part fluid resistant primers for their robust durability and peel resistance even if subjected to oils and fuel. . Even if mixed, I have a small refrigerator I toss paints and proseal mixes into, and can use it for several days before it cures. It really doesn't slow the build to the level mentioned, and if you "overthin" the product, it adds negligible weight. Dont even think about external prime until final paint , as the primer/paint process needs to be done all at once for best results.
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Interesting point Bill, never considered that Akzo would self-level that well. Do you happen to have any photos of a rolled/brushed surface?
 
1bigdog said:
In my opinion you should be ignoring opinions. Primers and paints are applied as part of a system and the manufacturers outline proper preparation and application. As to primers, many should not be applied on their own without a final coat. Some are not at all meant as anti-corrosion coatings so if the intent is to be protecting internal surfaces and mating surfaces choose somethings specifically meant to be used on its own. Alodine is a conversion “coating”. Chromate and phosphate coatings (many if not all) are also meant to protect on their own. SEM makes spray bombs that are pretty good if you want to avoid the bunny suit.
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I only have a small snippet of my interior with me..the primer you see on the inner skin is rolled. We cant spray in the heavy maintenance environment and rolling is the norm, even topcoat.
 

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I think it's a great idea. Even if there is any texture, and I don't see any, it will reduce glare.
Nice job.
 
fixnflyguy said:
I only have a small snippet of my interior with me..the primer you see on the inner skin is rolled. We cant spray in the heavy maintenance environment and rolling is the norm, even topcoat.
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A finishing "hot dog" sponge type roller?

I wonder which has more waste. Loading up the roller or spray waste. Would assume the lines cross in favor of the roller the larger the area being coated.
 
Freemasm said:
A finishing "hot dog" sponge type roller?

I wonder which has more waste. Loading up the roller or spray waste. Would assume the lines cross in favor of the roller the larger the area being coated.
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Roller in my case. I've fine tuned my spreadsheet and have spray waste down to ml. Very little. I also use syringes to pull pain and measure products. Almost no waste.
That said, sometimes a good application technique is worth a little waste.
 
How much does a gallon of corrosion X weigh? Over the years you’ll probably use twice that trying to coat the internal structure.
 
Freemasm said:
A finishing "hot dog" sponge type roller?

I wonder which has more waste. Loading up the roller or spray waste. Would assume the lines cross in favor of the roller the larger the area being coated.
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Yes..the little hotdog foamy roller, 3". It doesn't hold much to start with, since Akzo is water thin, not latex thick. I prime my fastener holes for bolts with a Q-tip, the skin rivet holes will self fill during roller application for the most part .
 
This turned into a "How to Prime" thread. I won't add to that, but to help the thread author I will say I'm only priming spars, where doublers cover and hide a surface and the non-alclad parts so you are not alone (I also scuff and prime if a part gets scratched up).

There was one comment about using ACF 50 when the plane is new and then every few years (depending on where you live). That is my plan as well, but keep in mind you DO NOT want to do that before your plane is painted.
 
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This is my process, after research and much consideration this is the most efficient process I could come up with. Yes, it adds time to your build, but in the end, IMO, when the plane is sitting completed, you’ll be glad you spent the extra time. Again, just my opinion.

  • Deburr the entire kit. Cut apart any part that is used to create multiple parts.
  • Build every sub-kit (including dimpling) to the point it instructs you to disassemble and prime. If the part is to be spray primed (over 36”) I scuffed the part before dimpling.
  • I then stored that sub-kit. Once every sub-kit had been completed, THEN I began the process of alodine/priming.
  • I alodined every part that would fit in my 36” containers. It took basically 2-3 days to alodine. Lots of tagging, wiring, and hanging parts. I did not prime or topcoat the alodined parts, alodine is all they get.
  • I sprayed any part too big to fit in the alodine containers. I primed both sides of my skins. I used the Akzo Noble product listed below. This product is fantastic!! It dries quickly and is very simple to mix and use, basically 1-1 mix. Like “bertschb” said, very easy to use.
  • After priming I stored every kit back on the shelf and only then, after all was alodined/primed, I began the permanent building.
I have Q.B. Fuse and wings with the factory wash primer.

AkzoNobel 10P4-3NF/EC-117 BAC377 Yellow BMS 10-11 Type I, Class A, Grade A Spec Structural Corrosion & Chemical Resistant Epoxy Primer - Gallon Kit at SkyGeek.com
 
milhouse1312 said:
Despite the risk of reigniting the war, I figured I'd consolidate a few thoughts I've had recently as I'm beginning to (re-)start my RV-14A project.

Prior to my laser cut parts replacement (and even after), I spent a TON of time trying to figure out what process to use to prime. I spent so much time, in fact, that I've actually decided to not prime... at least for now. Here's why:
  1. Priming is extremely time consuming and can add significant costs to the build. I never made it far in my kit before I halted due to the LCP issue, but I'd say between 1/3 and 1/2 the time I spent was on priming or prepping for priming. (i.e. scuffing parts, then rinsing, cleaning and degreasing, drying and finally priming, then waiting a day for the primer to cure.) It's a time sink. I'd estimate it could add 500 hours to the project overall. Between that and avoiding nasty chemicals, any hit to resale value (if any) is counterbalanced by the significant reduction in time, money and potential health consequences. Time is money. Materials cost money. Health is priceless.
  2. Priming will add weight. I plan on flying the plane primarily as a cross country machine. When loading up the airplane including the baggage area, the extra weight might adversely affect weight and balance, especially if that extra weight is way aft in the empennage I plan on restarting soon.
  3. I don't know where life will take me, but I currently don't live in an area with corrision problems. My local flight school has a 182 that's been sitting on their ramp in the elements for decades. Their mechanic has told me that airplane doesn't have any corrosion issues. He does apply ACF50 as a preventatitve measure to their unprimed airplanes every few years. Takes two people an afternoon. I've been there a while and have never seen the 'weeping' people on here complain about. Even if I end up in a corrosion-prone area, I will hangar the plane unlike my local school.
  4. I imagine I'll be done flying 30 or 35 years after this project is completed, and would almost certainly give up any aerobatics long before that. That means that if problems do start occuring in a decade or two, I'll still have an overbuilt airplane for the cross country mission.
  5. If corrosion becomes an issue, Corrosion X or ACF50 are options. There may even be a better product in the future. If it becomes a massive problem... well... I built it once, I suppose I can rebuild or build/replace major assemblies again. After all, I likely saved 500 hours the first time around.
  6. Here's the kicker: many builders who have primed their airplanes say they wouldn't prime their next airplane.
Seriously, this subject has totally stalled my build. I received LCP parts replacement a few months ago and haven't restarted, largely due to this issue. I've commited many hours to trying to figure out how to do this properly and efficiently. Now that I'm sick of being stuck in analysis paralysis, I've decided to build now and solve tomorrow's problems tomorrow. I'll scuff and rattle can the stuff that isn't alcald and leave the rest alone. FIgured I'd share this to help the next builders who get stalled over this issue like I did.
Click to expand...
Thank you for posting this. You just helped me dig out of my own analysis-paralysis on this issue. I'm following your lead! Thanks.
 
milhouse1312 said:
Despite the risk of reigniting the war, I figured I'd consolidate a few thoughts I've had recently as I'm beginning to (re-)start my RV-14A project.

Prior to my laser cut parts replacement (and even after), I spent a TON of time trying to figure out what process to use to prime. I spent so much time, in fact, that I've actually decided to not prime... at least for now. Here's why:
  1. Priming is extremely time consuming and can add significant costs to the build. I never made it far in my kit before I halted due to the LCP issue, but I'd say between 1/3 and 1/2 the time I spent was on priming or prepping for priming. (i.e. scuffing parts, then rinsing, cleaning and degreasing, drying and finally priming, then waiting a day for the primer to cure.) It's a time sink. I'd estimate it could add 500 hours to the project overall. Between that and avoiding nasty chemicals, any hit to resale value (if any) is counterbalanced by the significant reduction in time, money and potential health consequences. Time is money. Materials cost money. Health is priceless.
  2. Priming will add weight. I plan on flying the plane primarily as a cross country machine. When loading up the airplane including the baggage area, the extra weight might adversely affect weight and balance, especially if that extra weight is way aft in the empennage I plan on restarting soon.
  3. I don't know where life will take me, but I currently don't live in an area with corrision problems. My local flight school has a 182 that's been sitting on their ramp in the elements for decades. Their mechanic has told me that airplane doesn't have any corrosion issues. He does apply ACF50 as a preventatitve measure to their unprimed airplanes every few years. Takes two people an afternoon. I've been there a while and have never seen the 'weeping' people on here complain about. Even if I end up in a corrosion-prone area, I will hangar the plane unlike my local school.
  4. I imagine I'll be done flying 30 or 35 years after this project is completed, and would almost certainly give up any aerobatics long before that. That means that if problems do start occuring in a decade or two, I'll still have an overbuilt airplane for the cross country mission.
  5. If corrosion becomes an issue, Corrosion X or ACF50 are options. There may even be a better product in the future. If it becomes a massive problem... well... I built it once, I suppose I can rebuild or build/replace major assemblies again. After all, I likely saved 500 hours the first time around.
  6. Here's the kicker: many builders who have primed their airplanes say they wouldn't prime their next airplane.
Seriously, this subject has totally stalled my build. I received LCP parts replacement a few months ago and haven't restarted, largely due to this issue. I've commited many hours to trying to figure out how to do this properly and efficiently. Now that I'm sick of being stuck in analysis paralysis, I've decided to build now and solve tomorrow's problems tomorrow. I'll scuff and rattle can the stuff that isn't alcald and leave the rest alone. FIgured I'd share this to help the next builders who get stalled over this issue like I did.
Click to expand...
Compromise: degrease, rattle can zinc chromate
 
At the risk of bumping a somewhat aging thread, I just wanted to add one thing. When I initially started prepping with Ekoetch and maroon scothbrite, I was really over doing it. If you just think about “cleaning” the part with acid using a scotchbrite sponge rather than counting on the scotchbrite to physically etch the part, you’ll be fine. Let the acid do its work. You will quickly find the aluminum to be water break free with minimal scrubbing. Don’t sweat it.

Also I’ll say that down here in Texas where most of my priming was done above 80 degrees, the Stewart Ekoprime and Ekopoxy were both cured well enough to take a dimple within a few hours. I often primed and riveted the same day.
 
I found the sherwin willams pg60 g2 would dry in a few minutes. But it contains solids so needs to be mixed well, like shake the can At home depot. Good stuff and happy w results. Sprayd really easily.
 
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