A short explanation/demonstration of preparing bare aluminum using acid and conversion coating techniques in preparation for painting an aircraft skin.
Very helpful thanks. Maybe you can shed some experienced light on method I am thinking of doing. I am painting a very shiny, very smooth 3020 or 3002 1/8" aluminum tool box I had made. My plan is to first use an automotive degreaser and cleaner prep. Rinse. Etch with red scotch Brite pad. Then apply apple cider vinegar, rinse. Wipe dry. Apply 2-3 coats Moeller Zinc Chromate primer. Let dry over night. Sand with 600 grit wet dry sand paper. Then apply automotive ( spray gun application) and 2 coats clear sealer. Doesn't follow video. But it's a small project . From your experience is my method going to achieve adhesion to aluminum. ? Changes ? Thanks
This method is.for real airplane only or any aluminium stuff. I need to paint aluminium aircraft models and I'm wondering how to do it. First need to find rhe way how to take off 40 year old paint from it tham how to paint again. I am reading there are some chemicals which remove easily but I'll try with that. I was thinking air sanding method too😮
Very helpful video. Good product info to use and steps to use them information. Reading comments. I think the word "instructional video" is useful. It was a demonstration of what to use and how to use it. The comments are common sense for anyone who works with chemicals. Sure he could have added three minutes explaining everything about chemicals from drinking to discard clothing (optional) however every product has warning and use instructions on the label. Always read the labels. Again thanks for the instructional video.
Alumiprep isn't necssary. You can use a white scotchbrite pad and water to scrub the aluminum until water doesn't bead on the surface anymore. Then apply the alodine. The key is clean until water sheets not beads on the suface.
Good information. Thank you. And I would agree with another post...hydrofluoric acid is rough on your hands....gets under your finger nails and eats the soft tissue. Pump up sprayer perhaps?
Question, I have an aluminum "Birdcage" if you will that will be INSIDE the aircraft after cover. Could I clean the aluminum and then alodine it as you show and leave it bare as it will be under the covering?
Im not painting an aircraft, but a tailgate made of aluminum on a 2008 ford expedition. Ford improperly prepared these and paint pealed off. In patches. After the alumiprep 33 and alodine 1201, is there any special primer that should be used? Such as a self etching primer? Should i use a sealer, like epoxy primer, after that ?
I am going to use this technique to refinish some designer aluminum patio furniture for a customer. I am a professional floor finisher doing hardwood, decks, garage floors, patio and driveways etc. If you have ever seen steel/iron outdoor furniture that rusts at the feet and constantly leaves rust spots on the ground, I have fixed this by cleaning with splash brand name metal prep (phosphoric acid based) from the home center (home depot paint dept) and then coating not with paint but with a specific commercial epoxy called seal krete HP 9100. Now on a job coming up its designer patio refinishing bit it isn't steel or iron, it's aluminum. I'll make a video and post a link when done.
Scrub the new Ali with Deoxidine and nylon brush or scotchbrite until you have a water wet break free flow, dry the Alocrom 1200 starting from the bottom up, you're after a tea colour on the Ali, test the Alocrom for adhesion if all OK epoxy prime. Top coat within 24 hours or moisture is absorbed. That's what is was taught as a young military aircraft painter 36 years ago.
Hi. Thanks for the info. I’m painting my old Southbend 10L lathe. It’s cast iron and I’m using an epoxy primer before the top coat. But some of the panels are aluminum. So I’m wondering what I need to do prior to the epoxy primer. Should I use both the products you mention? I’ve always heard that you should alodine an aluminum surface prior to painting, but what about the first product? Both are expensive and if I can use something like an acid I already have it would save me some money. Your comments are appreciated. Thanks, Paul
How do you remove the acid from inside of the fuselage? I cringed when I saw you brushing the first solution on as it seeps in to the cracks and crannies including the rudder exit holes and angle on the bottom of the fuselage. That little garden hose action surely did nothing to remove that acid from inside of the fuse.
When I painted airplanes, we would clean the surface with a scotch Brite and lacquer thinner, then apply the acid, rinse, then the alodine.the after dry, prime.
How do you remove great epoxy primer off aluminium , I have used many different kind of paint stripper , the paint comes off no problems but the green primer on my Cessna 172Just barely wants to come off , what is the best way
Have you tried aircraft paint remover (example: Rust-Oleum Part # 255448)? It's very strong so be careful where you apply it as it will eat through plastics too. www.amazon.com/gp/product/B003Z8XUAQ/ref=oh_aui_detailpage_o07_s01?ie=UTF8&psc=1
@@hnacion you can't buy the good stuff anymore. Obama's EPA banned methylene Chloride the active ingredient. You have to have a business license to get it. Benco b15 or b17 will work well
When you are installing the alumiprep and rinsing the area, what do you do about the water and alumiprep that washes into the open areas of the plane and gets inside?
@@evgi2329 well if a battery leaks acid you get corrosion. The acid causes huge problems with adhesion. The way these people soaks the acid on the plane the acid creeps behind the panels and the corrosion begins. This whole this is a supplier sales pitch that does more harm the good. An aluminum primer is a much better choice for good adhesion!
Good video. Two questions: 1. Should this process be done immediately before painting ie the same day? How long can you wait before prime/paint? 2. How safe is this for the immediate environment as the applications drip off the airplane and later hosed off? Should this be performed somewhere where the runoff can be contained like anti ice fluid? Just wondering. thanks for positng
+guintube I believe that once BOTH steps have been performed, there is no rush for painting. Of course, wash aircraft prior to painting if needed. Chemical/environmental issues: contact manufacturer for answers. Thanks
Best practice is to do this prep on the individual parts prior to assembly. That's how Beech, Cessna, Boeing, Lockheed and a host of others do this on their factory assembly lines.
guintube The reason is that Alodined surfaces are hygroscopic. I work for an aircraft manufacturer and we tried some simple tests to see if we could extend the period of time between chem and paint (to try and ease production demands), but ended up with adhesion issues on parts over 3 days old (failed wet tape adhesion and dry impact tests). If you have a humidity-free area, it can be done I would think.
I believe you can acid wash (first step) to clean the aluminum, but do not perform the chrome conversion (2nd step) if you want to polish. That 2nd step chemically alters the surface of the aluminum and am not sure that will shine up... BUT, that would be worth trying as an experiment....!
There is another form of alodine that can and is used for external aluminum surfaces that are not going to be painted as a corrosion inhibitor. It's Alodine 1500-1501. Example is the bright shiny surfaces for instance on American Airlines birds. You get the protective layer without the bronze staining. (Former commercial airlines mechanic)...Also keep that alodine away from steel fasteners...Bad juju. Commercial FBO's dont even bother with the aluma prep acid... Red scotch brite to prep the surface, wash with water until you get a clean sheen...Then alodine 1200 & Neutralize with water...Then green FR primer, then your external paint. Also pay attention to the grain of the material when scotch briting a surface for 1500 prep. Alodine is not necessarily a paint prep. It is a corrosion inhibitor by applying the chromic coating to the alclad. Scotch brite alone while rinsing the surface for a clean sheen without beading will do the trick. The scotch brite roughens the surface just enough to give the paint something to stick to. We are talking microns here. Paint does not apply well to any perfectly slick surface. If the water beads the surface is too slick and/or there are still contaminants on the metal...neither is acceptable.
@@swtnlnly I realize this is 5 year old post but.. Is the Alodine 1500-1501 the final step? Apply and rinse? Or apply with scotchbrite? Then rinse. Thanks. Losing the bronze tint is what I'm after on an aluminum Jeep part.
I paint planes for a living a couple of tips use spray bottles with a fine mist flush all etch and alidine from nozzles with clear water for storage always use red scotchbrite to scrub the etch into the aluminium then rinse thoroughly after about 5 min then completely dry using towels compressed air and if message let air dry the next step will not stick to a wet surface now mist on the alidine keeping it wet for a bit the time will vary depending on how thorough the first step was done so I suggest trying a small test see a first to figure out the time you are looking for a light golden brown color to long well burn. And it will be dark if this happens restart process with etch
@@dawinner777 you are correct if acid is left behind in these areas and that is why it is of the utmost importance to rinse thoroughly the acid is already watered down and what water you add to it pretty much deactivates it but yes take a special care to make sure that the seams are rinsed very well also the answer that is made for aluminum it's sold as aluminum prep it cleans the pores of the aluminum free of sanding or Scotch braiding dust which can also lead to corrosion if left behind under the paint and most definitely will lead to paint blistering
I'd definitely suggest not applying it like it's being shown - Alodine has hydrofluoric and chromic acid in it. Wear gloves on BOTH hands and put some safety glasses on.
totally agree about your comment about PPE including full face respirator if spraying it. Its ridiculously bad for the person and the environment also, dont know where these guys are rinsing the solution, perhaps the environment in America doesnt matter. Any clean water works, but the trick is to get the aluminium oxide coating off, keep it wet and apply when its still wet. I dont see any wheat coloured hue from correct application in this video and i think its only a representation of correct application rather than a really good application. But meh, it might be. From my experience as an AC refinisher it takes a bit more elbow grease than that and you know when youve applied it correctly, but if youre a home enthusiast learning from you tube, you might Alodine an entire AC and not ever know that what youve just done has achieved absolutely nothing.
We have a similar closed system sump for the same types of chemicals. Otherwise if its done away from the hangar we use cut open drums to collect the wash off and pump or tip them into the old stripper containers for re badging for disposal. Works ok. Ive seen it too, where a stone chip on the LE from the prop or a nick in the paint has happened round a rivet and you can get an air duster and huge sheets come off in swages lol then you have to feather it out and do the whole nine yards...real pain If theyre not getting the wheat colored coating tbh, its probably best to just forget a poor alodine application and sand it with 240 and be done with it, AC primer will stick to that no problem. Id rather have paint on a 240 surface than a polished scotchy surface anyday, but thats just me.
This method is.for real airplane only or any aluminium stuff. I need to paint aluminium aircraft models and I'm wondering how to do it. First need to find rhe way how to take off 40 year old paint from it tham how to paint again. I am reading there are some chemicals which remove easily but I'll try with that. I was thinking air sanding method too😮
Yes. It says So on the bottle. You get cancer. And you should take care of the waste. What he is doing is not oké. May suggest you read the product sheet. It’s a henkel product. It’s easy to find.
Need window min/max information for application of next material Then what material can adhere Eg - 4 hours max, 72 hours max Minimum - wait 30min At what temp Before applying primer or topcoat Will an epoxy primer bite into it /adhere , then go with a finishing method from there of our choice
Those old Cessnas were mostly alclad so no Alodine. It is a different method of achieving corrosion resistance. And they will also rot out like swiss cheese.
Acid under the panels and around rivets is horrible and will corrode the panels. Not a fan of acid. Especially when you drench it. Scuff and clean with alcohol and use an aluminum primer to make it adhere. Then paint it.
I disagree, applying alodine to assemblies allows the chemicals to get in between the sheets and the rivets reducing the strength. Alodine does not add, it subtracts. Mechanical prep and acid cleaning is ok, then prime.
