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Painting Aluminum???

Vans101

Well Known Member
I am trying to get geared up to paint some aluminum sheet metal and small aluminum parts. This is not an airplane project however I am practicing on this so as to figure out the basics before I do a real job.

I've only ever used rattle can paint and was very disappointed with the results so now I want to put on my big boy spray hood and learn to do it right so I am a complete newbie on the subject so any and all advice wanted.

Can someone please recommend the following:

-Easy primer to use (self etching/ epoxy/ other)

-Easy paint to use (once step color...not base clear coat)

-Type of thinner for the above

-Paint gun tip for the above

-Type of HPLV gun (make/model/ gravity/ updraft/ needle size/ other)

-Online source to buy the paint/ primer/ thinner

-Paint filters

-Clean up techniques and pro tips

-Website or video on how to paint (I imagine others have already screened through the kazillion websites/ videos out there and found a couple of sources that were better and cut to the chase and not hear the guy's life story before the actual education.

So for those who have just done the research on this topic can you please help me get moving in the right direction?

THANKS!!!
 
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Your list is missing the most important part: prep work. The best paint in the world is no good on a poorly prep’d surface. You should ask:
What cleaning agents, what de-greasers, what mechanical scuffing aids, what etching chemicals are used, and how. After that most paints will stick okay.
 
There's a whole Painting section of the forum. A number of your questions are answered there.

Nearly every paint has manufacturer's instructions regarding prep, priming, drying, mixing, and so on. Some of the instructions are aimed at more experienced painters than others, but all are informative.

Dave
 
Prep

Wash the big obvious stains, dirt etc with Dawn dish soap and water using a rag. Like washing your car. Then use a concentrated solution of dawn dish soap and hot water with a scotch-brite pad and scuff it up. Rinse with water.Then make a alumaprep solution with cold water and do the same with a scotch brite pad. Wear gloves! Rinse with water. When the water drains off in just one big sheet with no splotches, you are ready to prime. If the water hangs up in spots, you need to keep on cleaning it. Start over again with Dawn dish soap and hot water. And hit it with the aluma prep solution and pad. Then, and only then will you be ready to think about priming.
 
Prep and cleanliness are key. I’ll work for days just to paint for 30 minutes. Lol :D

My current paint of choice is Sherwin-Williams Jet Glo conventional. Looks great, lasts long time. For thinner, use what’s listed in the technical data sheet.

For spray guns I recommend the Devilbiss GPG (used to be called the GPI). A 1.4 nozzle is a good all around size. It will spray everything you need. About $260 from spraygunsdirect.co.uk

You can use acetone, MEK, or lacquer thinner for gun clean up. Wear gloves when you clean. Don’t get it on you. Actually, wear gloves any time you are around paint. When doing paint work don’t wear any clothes that you don’t want to get paint on.

Disposable 3M PPS paint cups are worth their weight in gold. Harbor Freight has a clone of the first generation of cups. I’ve never used them so I can’t comment on their quality.

The old school way of surface prep is to wash with soap and water then wash with an acid etch solution, then treat with alodine. Works great but alodine is super expensive and hard to get. The best new school method is to wash with soap and water then wash two times with a product like Meta-Flex SP-1050. It’s an adhesion promoter and makes primer stick very well.

Hope this helps.
 
Wow...as always very grateful for the advice

>Water borne or solvent based...This decision will take your research down a fork in the road to material selection.

The answer is... I do not know. This is kinda like being married...just tell me what to buy an I will buy it.

I always assumed that automotive paints were solvent based and did not think water based was a thing outside of laytex house paint.

>My current paint of choice is Sherwin-Williams Jet Glo conventional

Ohhh...now that sounds good...however I looked at the prices and for this non-aviation project (aluminum sheet metal practice job) perhaps I can find cheaper. Any recommendations?

So my shopping list is now:

-Dawn dish soap
-gloves
-acetone, MEK, or lacquer thinner for gun clean up
-scotch-brite pad
-Meta-Flex SP-1050
-Disposable 3M PPS paint cups
-paint stir sticks
-filters
-What is that stand called that holds the filters
-Primer
-Paint
-Thinner
-???

What is a good source for all of this stuff? It would be good to order from one source and save on shipping.

Thanks again
 
Water based paints

I have been painting things of all sorts for 55 or so years. Cars, trucks, boats, houses, you name it.
I was a hard one to convert to water based in shooting houses ( built houses for 43 years) But the goods have come a long ways. You virtually can't even buy oil based paints for houses anymore.
The crazy thing is I invested over a $1,000.00 in a Hobby Air system right before we switched to water based primers and finish coats.
I interior trim packages for houses now are all shot with water based materials and I have actually found it better than the oil based products.
"""And you are asking ART! WHAT??? does this have to do with airplanes???????
Most painting systems are moving to water based/water borne products.
The Stewart Systems paint is pretty good stuff. Clean up a snap and No nasty stuff left over.
If you haven't painted much in your life, you might as well learn on the water borne products. You will enjoy the trip I guarantee it.
But, your luck may vary Art
 
I am trying to get geared up to paint some aluminum sheet metal and small aluminum parts.

Your tag says San Jose, so you might want to find a friendly auto paint store and ask questions. California tends to have its own rulebook.

Actually that's my standard advice...find a friendly local shop selling one of the major brands (PPG, BASF, SW, etc). Doesn't matter which one. Go with the shop which seems most helpful. Use their products exactly as the manufacturer specifies. And take 'em a six pack from time to time.

Special "airplane paint" is not required. All the major auto refinish systems are good.

Don't reject clear coat out of hand. Clear allows cutting and buffing over metallic and pearl base coats. C&B can turn average work into something real nice.

As others have noted, aluminum prep is generally some combination of detergent and acid. Personally I mix hot water, Dawn, and enough acid to make my skin sting, then glove up and scrub the snot out of it with a new red Scotchbrite pad. As noted, when water sheets everywhere, it's clean. Rinse, blow the seams with compressed air, rinse again, blow, let dry a day or two.
 
I know that you're interested in paint, but it might be worth checking vinyl wrapping. There are a few advantages:

It's lighter,
Less expensive,
Applies faster,
Doable in a workshop,
And more easily taught to beginner.

There are numerous colors available. 3M has a good sample pack. Metro Styling has a good site, good service, and offers small quantities of many manufacturers.

There are many YouTube videos showing how to do it, but be careful... the process differs slightly manufacturer to manufacturer.

As I got closer, I ordered foot square samples of several wraps. That gave me enough to compare. But my current thoughts are to paint the fuselage and wrap most of the rest. That might change, of course, as I get closer.

Dave
 
+1

Our Paint shop recently switched to Prekote for paint prep. Non toxic, biodegradable. And a gallon goes a long way.
https://youtu.be/jO_mbv9Uox8

I was not a PreKote fan, but my paint shop guaranteed it and preferred over etch, alodine prep. Sherwin Williams approved it for adhesion.

Although only an adhesion promoter, it really sticks . . . . inside the cavities, around fasteners and on the skins too.
 
I was not a PreKote fan, but my paint shop guaranteed it and preferred over etch, alodine prep. Sherwin Williams approved it for adhesion.

Although only an adhesion promoter, it really sticks . . . . inside the cavities, around fasteners and on the skins too.

When Meta-Flex SP-1050 (exact same as PreKote) first came out, I was given some to try. I watched their training videos and proceeded to prep and prime a piece of aluminum. The next day I scratched the aluminum with a razor blade and applied a piece of 3M aluminum tape. After letting it sit for awhile I ripped off the tape. All the primer held on. That’s very good. Later on I was talking to a tech rep and he said the one drawback is that it doesn’t like to strip off. When planes that are prepped with Meta-Flex come back around for repainting, I hope that I’m retired.
 
Our Paint shop recently switched to Prekote for paint prep. Non toxic, biodegradable. And a gallon goes a long way.
https://youtu.be/jO_mbv9Uox8

I wonder how well it would it work with Steward Systems EkoPoxy. Etching is the step that I don't particularly like right now.

One issue with Steward Systems EkoEtch is that I need to carefully track which part did I scuff when as leaving it for longer leaves corrosion (I think?) spots on the parts. Makes it inconvenient when working with lots of small parts.
 
I decided to try the Stewart Systems Waterborne paint.

For anyone going this route this is what I ordered:

EkoEtch - Aluminum Etching - Pint 1 Pt $14.37

EkoClean - Heavy Duty Cleaner/Degreaser -Pint $12.52 1

EkoPoxy - Waterborne Epoxy Primer with Catalyst for Aircraft - White - Quart-
1 qt $66.51 (this stuff is more expensive however it was recommended for surfaces that might get gasoline dripped on them)

EkoCrylic Waterborne Paint with Catalyst for Aircraft for metal Insignia White
1 Quart $97.59

I have no idea how it compares price wise to other traditional paints. I am just building a metal box to house a generator however it is good practice before I paint an airplane.

Sooooo...for those who have gone this route...PLEASE give any and ALL ADVICE!!!

THANKS!!!
 
I've used Stewart Systems Ekoprime and Ekoetch. My experience with their product was not good. I sprayed some test pieces and it seemed to go well. Then I spent hours prepping my Horizontal Stab parts and skins. I diluted the primer with about 8% distilled water by weight per the instructions and then sprayed the parts. The results were horrible. The primer was really thin and I was getting no coverage and terrible adhesion. I spent the next bunch of hours removing the primer, which fortunately came off very easy.

I contacted Stewart Systems to see if they would offer a refund or return, but no such luck. I was told that I needed to spray multiple lights coats, very very lights coats, until there was adequate coverage. No thanks...

I've switched to a different priming system.
 
First off, I have no affiliation with Stewarts Systems other than being a very happy customer. I have been using their paint since 2015. I have been painting my RV14 building over the last year or so as I finished the large parts. In the beginning (2015) I did not know how to use their paint. Made a bunch of mistakes and then figured it out with the help of the Stewarts tech support folks. Their paint is fantastic, strong as can be, easy to work with, and if you are shooting paint in your home (basement or garage) this is the only way to go. No smell. No toxic fumes. You still MUST wear protective clothing, a good respirator and goggles but after you shoot your pieces the clean up is done in a slop sink. Never any smell. For me, I get fantastic results with Ekoprime. When I use EkoCrylic top coat if get a really nice finish but I never get a glass-gloss look. I get a really great finish but I have a hard time nailing the gloss.

I use a FUJI HVLP turbine which is an incredible device. I paint up and bought the three stage turbine. I knew hooking up multiple compressors to get the consistent high volume of air that is needed was going to be a pain the arse....that is why I went with the turbine HVLP system. The only downside to the turbine HVLP system is that it generates heat through the air tube and that is probably why I don't get the perfect gloss in the end as the heated air gets in the way of the paint flowing out in the end...but, just to repeat, my results are absolutely amazing for a non-professional.

The process is simple:

1. clean the parts really good. This is easy for new parts. If they are dirty greasy parts its more work.

2. use Stewarts EkoEtch. Put it in a spray bottle and lightly spray your parts and your purple scotchbrite pad. Lightly scrube all surfaces to be paintted. Let sit for a few minutes and wash with the hose.

3. use alcohol or acetone on a rage to wipe everything down afterwards because there is always some residue left behind.

4. prime with ekoprime paint within a 24 hours period so that the aluminum surface does not oxidize. If it does you have to repeat steps 1 through 3 above. Ekoprime is a piece of cake to shoot. I don't event dilute it as I shoot it right out of the can. A few light coasts (let each coat flash almost dry before shooting again) is all you need. If you do it right you will barely have to sand before final paint. Nothing more that a purple scotchbrite pad and your ready for your color coat.

5. Ekocrylic is great. The old instructions were confusing. It is simple. Pour x grams of ekocrylic in a container. Take x times 25% of catalyst and put in the same container. mix and wait five minutes. Then add x time 25% of distilled water, mix and wait five minutes. All measurements are by weight, not volume.

6. Here is where you have to be careful. I screwed this up when I first starting using Stewarts paint. Scuff up the primer, sand or do whatever you must to making it smooth. Wipe it down, blow it off and clean it good (now water, alcohol or acetone). When you are ready to shoot the ekocrylic you must fog it on so slightly that after the first coat you can still see the primer. The first coat is almost like "peppering" the primer with the top coat. Walk away for about 15 minutes. Come back and do it again (cross hatch to the last coast). Second pass your "peppering" a little more. Come back again in 15 minutes and "pepper" it again. By this time the primer should no longer be visible....but the paint should have so gloss at all. It should be flat with no gloss. Next, walk away for at least 45 minutes. Come back and this is where you shoot the gloss coat. Turn up the spray volume and move slowly as you shoot (6 to 8") away from the surface. This is the final gloss coat. Here I get amazing results just short of "glass".

So, anyone who says that Stewarts Systems is bad simply does not know how to use it and/or is using the wrong gun and compressors. I got really good at using this paint and their is nothing better for the amateur painter. I forgot to mention that Ekoprime is amazing strong, one part and excess can be poured back into the container. Any excess Ekocrylic must get disposed of. For Ekocrylic, any extra I have I pour it into a cup and let it sit for a few days. It dries hard and I throw it in the garbage. No smell. No mess. No fuss.

Try it. From na-sayers stay away!
 
Chrissky (just kidding Chris Sky),

Very grateful for your write up!!!

So I settled on Stewart.

Now I need to get ALL of the stuff that is between the compressor and the aluminum panel I will be painting.

This is what I have already bought:

-EkoEtch - Aluminum Etching
-EkoClean - Heavy Duty Cleaner/Degreaser
-EkoPoxy - Waterborne Epoxy Primer with Catalyst for Aircraft White - Quart-
-EkoCrylic Waterborne Paint with Catalyst for Aircraft for metal White
-Paint filters provided by Stewart

Can someone PLEASE recommend ALL of the stuff I need?

-Water/ oil filter make/model???
-Air hose (new)
-Spray gun make/model???
-Dawn dish soap
-gloves
-acetone, MEK, or lacquer thinner for gun clean up
-scotch-brite pad Color
-Disposable 3M PPS paint cups (or equivlent???)
-paint stir sticks
-What is that stand called that holds the filters

Any help writing my shopping list would be greatly appreciated!!!
 
-Water/ oil filter make/model??? https://www.amazon.com/Devilbiss-803643-Filter-Cleaner-Regulator/dp/B00DGTOIEQ

-Air hose (new) https://www.amazon.com/Flexzilla-Fi...r_1_5?keywords=Air+hose&qid=1659563923&sr=8-5

-Spray gun make/model??? https://spraygunsdirect.co.uk/product/devilbiss-gpg-all-purpose-gravity-spraygun/ 1.4 tip for paint, 1.8 for primer.

-Dawn dish soap

-gloves https://www.amazon.com/SAS-Safety-6...refix=sas+safety+latex+gloves,aps,179&sr=8-33

-acetone, MEK, or lacquer thinner for gun clean up *All three will get the job done. MEK is probably the hardest to get. My choice would be acetone.

-scotch-brite pad Color *Red Scotch-brite p/n 7447

-Disposable 3M PPS paint cups (or equivlent???) *original 3m pps cups or these https://www.harborfreight.com/unive...r-kit-17-pc-57508.html?_br_psugg_q=paint+cups

-paint stir sticks *go to your local automotive paint store and buy a bunch of quart mixing cups. They will probably give you a handful of mixing sticks.

-What is that stand called that holds the filters *I just set the filter in the top of the pps cup

Hope this helps
 
Parts

I know nothing about water based paints but I've sprayed quite a bit of solvent based. My tools in red below.

Chrissky (just kidding Chris Sky),

Very grateful for your write up!!!

So I settled on Stewart.

Now I need to get ALL of the stuff that is between the compressor and the aluminum panel I will be painting.

This is what I have already bought:

-EkoEtch - Aluminum Etching
-EkoClean - Heavy Duty Cleaner/Degreaser
-EkoPoxy - Waterborne Epoxy Primer with Catalyst for Aircraft White - Quart-
-EkoCrylic Waterborne Paint with Catalyst for Aircraft for metal White
-Paint filters provided by Stewart

Can someone PLEASE recommend ALL of the stuff I need?

-Water/ oil filter make/model???
above is similar except I run a RTI Micro 1/4" regulator and an HF red disposable separator at the gun. Hose, regulator, fiilter, gun
-Air hose (new)
Above is fine but if you use HVLP, get the biggest diameter hose you can.
-Spray gun make/model???
https://www.harborfreight.com/20-oz-professional-hte-compliant-gravity-feed-air-spray-gun-56153.html It's a copy of a SATA and a heck of a spray gun. Get the adapter for the 3M PPS Cups too.
-Dawn dish soap
Why? I clean and scuff with Bon Ami. Two bird
-gloves
6Mil Nitrile
-acetone, MEK, or lacquer thinner for gun clean up
lacquer thinner but water based can be washed in the sink. I think
-scotch-brite pad Color
Maroon. Scuff while washing with Bon Ami. Rinse well and shoot within two hours
-Disposable 3M PPS paint cups (or equivlent???)
3M PPS 200 Micron
-paint stir sticks
big ones. Label them. Also buy Grainger 60ml Rubberless Syringes for sucking out and measuring paint. Zero waste. Label them.
-What is that stand called that holds the filters
No need. 3M PPS cups each have a 200 micron filter.

Any help writing my shopping list would be greatly appreciated!!!
 
I was told that I needed to spray multiple lights coats, very very lights coats, until there was adequate coverage. No thanks...

Did you not read the instructions? They specifically say to spray some tack coats.

If you follow the instructions, the entire system works great and a joy to use.

Like others have mentioned, you can just cleanup with a water hose or if your wife is out in the kitchen sink :D

Also, it is waterborne, not water based, there is a difference ...
 
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