Aluminum window frames peeling

cardude01 · Feb 3, 2016

My boat came with some nice PH windows from American Marine Inc.

American Marine, Inc. | Home Page They are aluminum-framed windows that were painted or powder coated (not sure which), but they are starting to flake off in spots and the underlying AL is oxidized.

Is there a good method to refinish something like this? Looks like it would be a pain to try to scrape/sand the frames while they are in the boat, but it may be more of a pain to remove them and reinstall without making them leak.

A buddy of mine is a carpenter/boat builder and he has a bad a$$ CAD saw system. He is always cutting out intricate shapes for different projects, so I was wondering about cutting out thin Starboard (or similiar) to the exact dimensions of the painted frame, and just attaching that to the peeling aluminum frames somehow (which may be difficult).

cardude01 · Feb 3, 2016

Windows look like this:

ImageUploadedByTrawler Forum1454523964.036505.jpg

Tolly Roger · Feb 3, 2016

I had all new windows made for our boat 4 years ago. They are aluminium and powder coated to match the gel coat. Last Summer I noticed one was peeling as you describe. In just a few months it got considerably worse so I called the manufacturer who said the fix was to remove the window and sent it back to be sandblasted and re powder coated under warranty. The secret is in the wash that they get just prior to powder coating.
I just got it back and re-installed it.
I think once they start to go there is not way to stop the oxidation from peeling the paint off.
I think covering the frame will just hide it and may even accelerate the damage.
For me it was not a big deal to re&re it so it made sense to fix it properly.

Steve · Feb 3, 2016

I had some oxidized blistered patches on the Al.window frames of my previous boat. I scraped off the loose powder coat, cleaned it up the oxidized crud with a stainless "mini brush" lightly sanded to smooth the surface, cleaned it well then applied, per instructions, primer for aluminum. I think it was zinc chromate, then painted with a good enamel marine paint, I sold the boat 2- 3 years later it still looked fine.

RT Firefly · Feb 3, 2016

Greetings,
Mr. 01. I agree with Mr. S. Clean the blistered areas off well, prime and brush on a good color match enamel. Unless you're REALLY anal, removal of the windows and re-coating is WAY too much work and bother.

cardude01 · Feb 3, 2016

Ok. Good news on the painting possibility. I'm not super picky.

Just brush it on-- like maybe a foam brush? I'm not the best painter. ?

Would like to only paint the small areas that are peeling, unless when I start to prep it all starts falling off.

RNL · Feb 3, 2016

I did exactly what #4 and #5 posts suggested about 8 or more years ago on spots on the aluminum trim around my salon windows. There were areas of "bubbling/blistering" oxidation under the paint. I sanded to clean metal and feathered the edges and used a 2 part Interlux product with the etching primer included in the box and just brushed on the enamel to color match my salon and it looks good to date. Haven't had another need to reapply.

RT Firefly · Feb 3, 2016

Greetings,
Mr. 01. "Just brush it on-- like maybe a foam brush?" I'd probably use an artist type brush since you'll hopefully be doing just small areas. Sounds like Mr. RNL has a good product or as suggested, any good enamel should work. Remember, a repair of this type is 90% prep work.

koliver · Feb 3, 2016

I had the same problem with the aluminum supports to my upper helm seat. a little prep, a little white varathane, applied with a 1/4" brush. Years later, still good.

gaston · Feb 3, 2016

Same problem here all I did was rub the spots with 3M green pad wipe with acetone and use single pot epoxy using a air brush .

cardude01 · Feb 3, 2016

My frames are kind of a beige color. Is it possible to find color matching paint?

RT Firefly · Feb 3, 2016

Greetings,
Mr. 01. How about going to a hobby shop and getting some model paint. Use small amounts of the model enamel to custom tint your marine white.

OR...

Just a thought and I am NOT responsible for YOUR color matching, thank you very much!

rwidman · Feb 3, 2016

cardude01 said:
My frames are kind of a beige color. Is it possible to find color matching paint?

Paint stores can usually match a sample if you bring one in.

My painted metal windows are fading and I plan to paint them in place with a brush.

eyschulman · Feb 3, 2016

It is important to do a good prep and use the proper primer meant for aluminum. I had good luck on a boat using foam brushes and one part paints.

cardude01 · Feb 3, 2016

eyschulman said:
It is important to do a good prep and use the proper primer meant for aluminum. I had good luck on a boat using foam brushes and one part paints.

Is the correct primer zinc chromate like someone mentioned earlier?

eyschulman · Feb 3, 2016

cardude01 said:
Is the correct primer zinc chromate like someone mentioned earlier?

I believe it was but check with your paint store to be sure. Sort of a green yellow color.

BruceK · Feb 3, 2016

cardude01 said:
Is the correct primer zinc chromate like someone mentioned earlier?

I think you need an etch primer.
Priming aluminum/aluminium needs to be done immediately sanding prep is finished or large nasty bubbles of non adhesion develop(eg. painted alloy covers on Muir windlasses).
I refinished windscreen aluminium window frames more likely anodized silver than powder coated. Finish was sound but dull, after sanding a one pack epoxy paint not requiring primer brushed straight on, and looked good. Would that the current boat had aluminium frames, not timber

, however much in need of paint.
Zinc chromate primer here is red/brown, etch primer is yellow green and a bitch to apply well.

AusCan · Feb 3, 2016

Make sure the etch primer is completely dry before painting. (>24 hrs)

Here are some good tips.
Etch Primers - what are they?

Gurryman · Feb 3, 2016

Simple & Best answer to refinishing aluminum is "Alodine" Learn how to prep and apply it correctly and you will disregard all the home remedies!

psneeld · Feb 4, 2016

DGR Industrial Products, Inc. :: Specialty Coatings :: Conversion Coatings :: Alodine Chromate Conversion For Aluminum Alloys :: Henkel Alodine 1201 Chromate Conversion Coating

Applications in which temperatures can reach over 120ºF can break down the corrosion resistance

of the coating. In comparison to anodizing, this chemical film is more fragile and

not generally recommended for high-use areas.

Wonder if my black window frames would be a candidate for Alodine as they easily go over 120 deg F in the summer.

http://www.eaa1000.av.org/technicl/corrosion/alodine.htm

Gurryman · Feb 4, 2016

psneeld said:
DGR Industrial Products, Inc. :: Specialty Coatings :: Conversion Coatings :: Alodine Chromate Conversion For Aluminum Alloys :: Henkel Alodine 1201 Chromate Conversion Coating

Applications in which temperatures can reach over 120ºF can break down the corrosion resistance

of the coating. In comparison to anodizing, this chemical film is more fragile and

not generally recommended for high-use areas.

Wonder if my black window frames would be a candidate for Alodine as they easily go over 120 deg F in the summer.

Alodining

The temp limitations refer to Alodine applications that are not top coated, as the Alodine will dehydrate. I have used Alodine in many applications and results have been better than expected.

The temperature restrictions apply to unpainted Alodine®. The powder coating protects the chromate from dehydrating and cracking during the high temperature cure.

Adhesion problems due to improper chromating could be due to:
1) Poor aluminum pretreatment (e.g., over-etching, wrong deoxidizer for castings, dirty rinses),
2) Dirty post-chromate rinses; final rinsing in DI water is best (if not using a Deoxylyte® final rinse),
3) Excessively thick chromate; try Type II per ASTM B449-93 [link by ed. to spec at TechStreet] (twixt Classes 1A & 3 of Mil-DTL-5541 [link is to free spec at Defense Logistics Agency, dla.mil]).
4) Under-cured chromate (soft gel, lacking strength),
5) Over-cured chromate (powdered & cracked. Metal temperature shouldn't exceed 150 °F).

See the appropriate Alodine product bulletin or Mil-HNDBK-509 [link by ed. to spec at TechStreet] CLEANING AND TREATMENT OF ALUMINUM PARTS PRIOR TO PAINTING for more info. Final rinsing in Deoxylyte® (rather than DI water) is given. Most Deoxylyte versions are dilute chromic acid solutions; Henkel likely has a non-hex. chromium version by now.

What adhesion & corrosion testing is currently performed? In letter 45803, Sheldon Taylor describes D-I-Y testing of X-scribed painted samples in boiling water, similar to ASTM D870 [link by ed. to spec at TechStreet]. Another quick test is adhesive tape testing of crosshatched samples, see ASTM D3359 [link by ed. to spec at TechStreet] or search this site. If successful with these, then do the more rigorous tests. E.g., have scribed samples tested by a lab per ASTM D2803 [link by ed. to spec at TechStreet], 'Standard Guide for Testing Filiform Corrosion Resistance of Organic Coatings on Metal,' either Procedure A or C (both are salt-fog followed by humidity). Letter 38976 "Specifications for Powder Coated Aluminum -- AAMA 2603, 2604, 2605" gives additional tests.

psneeld · Feb 4, 2016

Thanks...the second link I placed seemed to indicate issues about no top coating but wasn't exactly clear about it.

cardude01 · Feb 4, 2016

This Adoline stuff is great info, but I'm not sure how I will etch my frames on the boat without it dripping all over my nice shiny gelcoat under the windows.

Guess I could try to tape off the gelcoat with plastic maybe.

caltexflanc · Feb 4, 2016

Are the frames fastened to the boat with stainless steel screws and is some of the peeling adjacent to the screws? If so, make sure you re-bed those with something like TefGel or you will have peeling all over again.

KneeDeep · Feb 4, 2016

CarDude- come on over about 4 slips for plenty of spots for you to practice on while you perfect the technique.

Seems this task keeps slipping down the to-do list.

cardude01 · Feb 4, 2016

KneeDeep said:
CarDude- come on over about 4 slips for plenty of spots for you to practice on while you perfect the technique.

Seems this task keeps slipping down the to-do list.

Ha! You don't me working on your boat!

Aluminum window frames peeling

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