Aluminum window frames peeling

I think I asked about this before but I can't seem to find the thread.

I have aluminum window frames and some of them are starting to peel. I think maybe they are powder coated? One window has a 2x5" section where the paint completely fell off in a sheet. The aluminum feels powdery underneath.

I'm not a very good painter, so I'm wondering if I should tackle this. If so, how would I scrape the rest of the paint off, and isn't it hard to get the paint to stick to aluminum? Can I do this with the windows still in the boat?

Maybe I could leave the windows bare aluminum after removing the paint and prepping, but that would probably look crappy.

My window with the big bare spot looks like this just FYI. This is not my actual window-- I forgot to take a pic. Are these type window frames easily removable?

Bare the aluminum will still corrode. Sand, use a marine primer for aluminum, lightly sand the primer and paint with final color.
Yes, you can do them in the boat. They will have some sealing/caulking compound that may make them difficult to remove. If they don't leak, I'd leave them in.

Subscribed.

I have similar issues just starting on painted aluminum intake vents on the side of my boat. The builder pointed out to me the very beginnings of some blistering of the paint in spots during the survey. He said they changed how this was done because of the problem. Eventually, I will probably need to do the same thing.

I have the same problem. I think I will ignore it. From more than 10 ft away I don't see it. I have built and painted an aluminum airplane, and it wasn't too major of a chore, but I was dealing with new aluminum. Airplane was a four step process. Alumiprep, alodyne, epoxy primer and Durethane topcoat. On chinese made extruded aluminum, I think that you could make it look better but I don't want to guess how long it will last. Keep the rest of the boat nice and shiny and nobody will notice. I think it would cost near 20k to switch to the windows with the SS frames. Dan

You`ll need to get primer on the bare aluminum asap after you prep sand it. Something happens fast, oxidization I think. If it gets there before the primer you`ll get paint bubbling.

You can sand the frames down but I would still etch them prior to applying the primer coat. Use an epoxy base primer designed for aluminum and then your final coating. You can brush it on but if you're looking for a nice finish nothing beats spraying. You can use an air brush gun on a job like this. If you don't have one, buy one....they're not expensive and way less expensive than a professional painter!

Many posts have mentioned sanding your aluminum frames. A word of caution: the improper use of steel wool, steel brushes or carbon based abrasives can force small (read microscopic) pieces of steel into the surface of the aluminum this will result in dissimilar metal corrosion. This corrosion will develop under your new paint
Try and use non-woven, fiber pads (Scotch-Brite) pads. Chemical stripping would be better but may not be possible/compatible with surrounding surfaces. An aluminum wire brush or aluminum wool will work also.
Just a suggestion.

Capt.Bill11 said:

Surface Preparation and Priming - Aluminum

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Show off!!

I would like to spray these frames if possible so I don't have brush marks. I'm a pretty good rattle can spray painter, but never used an air brush sprayer. Not sure how I would control overspray however. Always some breeze.

cardude01 said:

I would like to spray these frames if possible so I don't have brush marks. I'm a pretty good rattle can spray painter, but never used an air brush sprayer. Not sure how I would control overspray however. Always some breeze.

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Lots of masking off, a HVLP gun and a still day should do it.

cardude01 said:

I would like to spray these frames if possible so I don't have brush marks. I'm a pretty good rattle can spray painter, but never used an air brush sprayer. Not sure how I would control overspray however. Always some breeze.

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The advantage of a small air brush is that you control the flow of paint with a fingertip. Start with just a bare amount of paint being sprayed, and you'll quickly gain confidence to increase the flow to get to the point of "glisten", when you move on. Because the area actually covered by the air brush with paint from three or four inches away is about an inch wide using any other type of sprayer just increases your chances of making a real mess.

If you aren't comfortable using two part paints, find a painter, because anything else won't be much of a solution.

Because the frames are discreet pieces, just mask them off. The airbrush over spray will be easily controllable.

cardude01 said:

I would like to spray these frames if possible so I don't have brush marks. I'm a pretty good rattle can spray painter, but never used an air brush sprayer. Not sure how I would control overspray however. Always some breeze.

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I've tried airbrush and found them tough to get enough paint thru it for even a small area.
I found the Preval sprayers worked well for small to moderate areas...just like a rattle can except you can use specialty primers & paints not available in cans...even 2 part mix paints.
Cheap to try...little lost if you don't like it.
Easy to find in any big box hpme stores and other places.

Bacchus said:

I've tried airbrush and found them tough to get enough paint thru it for even a small area.
I found the Preval sprayers worked well for small to moderate areas...just like a rattle can except you can use specialty primers & paints not available in cans...even 2 part mix paints.
Cheap to try...little lost if you don't like it.
Easy to find in any big box hpme stores and other places.

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Well that looks interesting. Thanks.

cardude01 said:

Well that looks interesting. Thanks.

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Before you invest in Prevals, consider a HVLP touch up gun.

MINI HVLP SPRAY GUN DETAIL TOUCH UP 1.0 TIP

Capt.Bill11 said:

Before you invest in Prevals, consider a HVLP touch up gun.

]

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Preval hardly an "investment" at $5-$6 and air refills $4
If you have a compressor and want a true gun by all means HVLP is the way to go

So the consensus is what kind of paint?

Epoxy based primer and epoxy paint of some kind? Can I kind of color match this paint to what I have ?

cardude01 said:

So the consensus is what kind of paint?

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You guys are scaring me.

I was thinking good surface prep, self-etching primer made for aluminum, and Rustoleum.

I've had good luck with this combination before, but I'm open to hearing why not.

Bacchus said:

Preval hardly an "investment" at $5-$6 and air refills $4
If you have a compressor and want a true gun by all means HVLP is the way to go

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Between priming and final finish you are going to use at least as many Prevals as the cost of a cheap touch up gun. And the gun can give you a better result.

cardude01 said:

So the consensus is what kind of paint?

Epoxy based primer and epoxy paint of some kind? Can I kind of color match this paint to what I have ?

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For best longevity and gloss, 2 part poly.

But a good epoxy will work.

CaptTom said:

You guys are scaring me.

I was thinking good surface prep, self-etching primer made for aluminum, and Rustoleum.

I've had good luck with this combination before, but I'm open to hearing why not.

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You can certainly do it that way.

But if you want the best looking, longest lasting finish there are other ways to go about it.

Just depends on where you want to end up.

CaptTom said:

You guys are scaring me.

I was thinking good surface prep, self-etching primer made for aluminum, and Rustoleum.

I've had good luck with this combination before, but I'm open to hearing why not.

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This is unfortunately a common problem. I know one Nordhavn owner who has reported very good results using Rustoleum Aluminum Primer, followed by Rustoleum finish paint. Both cans (he posted a picture) were labeled "Professional" which maybe is a different line of paints? I'm not sure. Haven't had to face it yet myself.

Actually, here's the primer https://www.rustoleum.com/product-catalog/consumer-brands/professional/aluminum-primer-spray

Followed by this https://www.rustoleum.com/product-catalog/consumer-brands/professional/high-performance-enamel-spray

Sanding off all the oxidation is obviously an important first step.

Not trying to denigrate the great advice you are getting for a fabulous finish, but:

I have an aluminum post supporting my FB helm seat. It was originally powdercoated white, but after 10 yrs or so of service the bubbling paint got to me and I pulled out a can of Gloss White Varathane and a small brush and after cleaning with a bit of sandpaper dabbed on some paint. It looked so much better than the original powdercoat, as that was now dull, that I repainted the whole thing. That paintjob is now 15 or 20 yrs old, and needs redoing, but the varathane adhered to the unprimed aluminum just fine for a very long time. Simple fix.

My NT's doors, windows, screens are all powdercoat aluminum. As the powdercoat fails, I'll sand area smooth, prime with Pettit's EZPrime, then cover with one or 2 coats of 2-part Pettit EZ Poxy. I use Pettit's 2-part because I can get a perfect match of NT's oyster gel coat (not a pure white) with a 3 to 1 ratio of Yacht White and White Sand. A small good quality artists brush will level out quite well.

The best one-part metal paint I've found, and one that has a near perfect leveling quality is POR-15. POR-15 is a system of cleaners, primers, thinners, and paint. At the minimum, you'll need their thinner (solvent), nothing else works. Note that this paint adheres aggressively, and if spilt or splattered, would be near-impossible to clean up.

Rebel112r said:

I have the same problem. I think I will ignore it. From more than 10 ft away I don't see it. I have built and painted an aluminum airplane, and it wasn't too major of a chore, but I was dealing with new aluminum. Airplane was a four step process. Alumiprep, alodyne, epoxy primer and Durethane topcoat. On chinese made extruded aluminum, I think that you could make it look better but I don't want to guess how long it will last. Keep the rest of the boat nice and shiny and nobody will notice. I think it would cost near 20k to switch to the windows with the SS frames. Dan

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This is spot of for the paint steps. I'd add a light sand blasting to properly prep the aluminum vs hand sanding.

A decent tape job along with a light touch on a small blaster will give you excellent, cost effective results.

Conall

Watching this thread with interest, as I may be doing this soon.

So far I've done nothing with my frames. I did take some pictures however.

This is the frame with the worst peeling. Upper part of the frame seems good-- just the lower part on the frames are peeling, bubbling. Would be nice if I could just spot paint but it probably wouldn't match.

Ah, painted aluminum.... Unless you completely encapsulate the Al in paint, you will be wasting your time. If you do not completely remove all corrosion or if the paint membrane is damaged and water gets in (it's a boat, in the water) with the elimination of oxygen the Al will corrode underneath the paint and you get that lumpy, white surface that we all hate. It's only the filthy rich who can afford to build large aluminum boats, then paint them. Almost as bad as a wooden boat for paint issues.