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Rum_Pirate
04-28-2019, 02:25 PM
What is the best way to clean and put a shine on the older anodised aluminum tubes of a T-top?

Breakaway
04-28-2019, 03:43 PM
I have never had good luck returning shine to dull anodized aluminum. You need abrasives to cut through to bright metal--but the anodized layer is quite thin. So, you cut through and end up with the grey self-protecting finish of aluminum.

Try some rubbing compound and see how it goes. That is as aggressive as I would go.

Kevin

Rum_Pirate
04-28-2019, 03:46 PM
I was going to try Flitz
https://specbilt.com/wp-content/uploads/2016/01/flitz-logo-1.png

https://www.flitz.com/boat-cleaners-polishes-waxes-protectants-and-supplies

Anyone recommend it?

Todd Bradshaw
04-28-2019, 04:10 PM
This is an old anodized aluminum boat cover support that was pretty nasty looking. I rubbed a section down with Flitz and it came out pretty clean and shiny. What I don't know is the status of the anodizing after polishing. I just used a piece of flannel by hand and wasn't trying to scrub down to bare metal, but time will tell. Considering its original condition, the stuff made a drastic improvement without a horrible amount of labor.

36241

ahp
04-28-2019, 04:19 PM
Ordinary anodize doesn't weather very well. For small parts there is "Hard Coat" anodize, which is sort of pearl gray. It is used on weather instruments. It costs a bit more than the ordinary anodize. The aluminum should be cleaned up before that is done.

Rum_Pirate
04-29-2019, 09:04 AM
I have bought some 'Flitz' and will report back once my son (currently at Uni) has finished cleaning it.

MN Dave
04-29-2019, 11:12 AM
It sounds like a mild polish that might do the job without damaging the anodized coating. If the coating is already damaged, There isn't much you can do other than some kind of wax or lacquer. (http://www.corrotherm.com/coating-non-ferrous-metals/)

The coating is formed by oxidizing the metal in an electroplating like bath. It is a very hard coating, but usually only 0.0001-0.0002 inch thick. These links describe the coating and processes in more detail than most of us would care to read here:
https://www.anoplate.com/finishes/anodizing/
https://www.3erp.com/everything-about-anodizing-aluminum/

Thread drift...
Brush anodizing can be done (https://www.sifcoasc.com/selective-anodizing/) to repair or replace an anodized coating, but it is an expensive science project that I only mention because it bothers me to say that something can't be done when it can, technically. Never mind that it is utterly impractical, it is still possible. Since some metals can be colored by varying the coating thickness, brush anodizing has been used to 'paint' colored pictures on titanium.

Rum_Pirate
04-29-2019, 12:17 PM
It sounds like a mild polish that might do the job without damaging the anodized coating. If the coating is already damaged, There isn't much you can do other than some kind of wax or lacquer.

The coating is formed by oxidizing the metal in an electroplating like bath. It is a very hard coating, but usually only 0.0001-0.0002 inch thick. These links describe the coating and processes in more detail than most of us would care to read here:
https://www.anoplate.com/finishes/anodizing/
https://www.3erp.com/everything-about-anodizing-aluminum/

Thread drift...
Brush anodizing can be done (https://www.sifcoasc.com/selective-anodizing/) to repair or replace an anodized coating, but it is an expensive science project that I only mention because it bothers me to say that something can't be done when it can, technically. Never mind that it is utterly impractical, it is still possible. Since some metals can be colored by varying the coating thickness, brush anodizing has been used to 'paint' colored pictures on titanium.

Like your comment "Never mind that it is utterly impractical, it is still possible."

The 'brush anodizing' sounds interesting.

Pity that one couldn't EASILY and SIMPLY enclose a section (e.g. on a T-top) by taping (Duct tape?) on plastic film to the aluminum to be 'anodised', fill with an enriched liquid medium and add two wires from a power source (12v is too much to hope for?) thus electroplating the aluminum.

Sounds like a business opportunity to explore. :ycool:

Doswell
04-29-2019, 02:46 PM
This is an old anodized aluminum boat cover support that was pretty nasty looking. I rubbed a section down with Flitz and it came out pretty clean and shiny. What I don't know is the status of the anodizing after polishing. I just used a piece of flannel by hand and wasn't trying to scrub down to bare metal, but time will tell. Considering its original condition, the stuff made a drastic improvement without a horrible amount of labor.

36241
Todd: Once you have gone through the anodize coating, you are looking at raw aluminum. Raw aluminum will oxidize almost immediately upon exposure to air. The aluminum oxide will provide some corrosion protection but not much. If you decide to move forward, in my experience, the best way to polish aluminum is with aluminum polish. You can buy it at an auto parts store. I have used it on bikes and they come out great. After polishing, us a good car wax and the polish will last for a while. Without the anodizing, the surface of the aluminum will become dull over time and the car wax breaks down, and a new layer of aluminum oxide is created. It's probably not a very good idea in marine conditions. I do a lot of things like this but I wouldn't take this on. Good luck.

Todd Bradshaw
04-29-2019, 04:57 PM
This was just an experiment to see what Flitz would do, since I had some on hand and a few old bits of aluminum. The only "refinishing" I've ever had to do on aluminum was on the mast and boom of my iceboat, which came bare and non-anodized. About 20 years ago I rubbed them down to clean metal with Scotchbrite pads and immediately spray painted them with epoxy appliance enamel. I had a friend who had done the same to the stick on his Luders 16 and it was holding up OK, so I figured I didn't have much to lose. Granted, my spars don't get exposed to salt or liquid water and not even much UV, but they still look quite good and they no longer get black oxidation all over anything that touches them. If needed, it is also pretty easy to touch up.

JimConlin
04-29-2019, 09:25 PM
Then there’s powder coating.
One local shop can coat up to 20’ x 10’ X 10’ Or thereabouts.

Woxbox
04-29-2019, 09:37 PM
I've attacked old aluminum with steel wool, then sprayed on a primer made for aluminum, followed by good 'ol Rust-Oleum. It holds up well enough.

MN Dave
04-29-2019, 10:04 PM
Then there’s powder coating.
One local shop can coat up to 20’ x 10’ X 10’ Or thereabouts.Powder coating is baked to cure the powder. You have to be careful with the powder coat cure temperature and the aluminum heat treatment. Many powder coats are cured at a temperature that will soften the aluminum.

Rum_Pirate
04-30-2019, 08:32 AM
Beginning to sound better, time and expense wise, to buy a new T-top.

Breakaway
04-30-2019, 08:45 AM
The grey surface may not look spiffy, but does not affect the integrity of the top. Like teak kept clean, but left to go grey instead of oiled brown, it's an aesthetic. So, you may WANT a new top ( About $4,500 here) but you probably don't need one.

How bad is it? Post a pic.

Kevin

Rum_Pirate
04-30-2019, 09:03 AM
That US$4500 sounds high.

Mind you I would have to add sea freight to that cost then insurance and add 59% duty etc to the total figure. Ouch! :o

Final cost would more likely r be higher than your 'ballpark figure. :D

36408 36409 36410 36411



Will get some pics.

MN Dave
04-30-2019, 10:56 AM
The grey surface may not look spiffy, but does not affect the integrity of the top. Like teak kept clean, but left to go grey instead of oiled brown, it's an aesthetic. So, you may WANT a new top ( About $4,500 here) but you probably don't need one.

How bad is it? Post a pic.

KevinOnly $4500? Well, it might be a nuisance, but frequent polishing and waxing shouldn't be any more trouble than keeping brass nice and shiny. Kevin has a point, you could always learn to embrace the gray, like old teak, but...

If the aluminum isn't making black marks on things, the anodize must be intact.

I did drop in a link to a lacquer that would do the job, but at $211.46 (https://www.eis-inc.com/metal-sealant/p-gly1700g?cid=paidsearch_shopping_google_brand_glyp tal&gclid=EAIaIQobChMIqO3S5o344QIVEtNkCh2TsAJgEAkYASAB EgIAQfD_BwE) per gallon, it isn't exactly inexpensive, and by the time you get it shipped, who knows. There are some old mentions of a 12oz aerosol in forums, but nothing recently. The datasheet (https://www.eis-inc.com/medias/sys_master/h79/hde/8796754837534.pdf) says that it covers 3000 square feet per gallon, so what with the coating lost to the brush, you will have 127 ounces more than needed. At least it will work on the brass too. PA is too far from the OP to have it applied by the manufacturer (http://www.corrotherm.com/about-us/). An automotive clear coat might be worth a shot. OEM coatings are great, if you are an OEM.

Another coating that like powder coating may have a cure temperature that screws up the heat treatment (or not, you have to talk to the applicator) is the Cerakote (https://www.cerakotehightemp.com/news/article/cerakote-vs-jet-hot/) polished aluminum ceramic exhaust header coating. It looks like polished aluminum, is very hard, can be applied to aluminum and will take quite a beating. There are a number of brands that sound very similar, and according to an applicator in VA, all ceramic header coatings are all exactly the same, so any place that applies bright shiny ceramic exhaust coatings differs in name only. If the cure temperature is over 350F (it's been 13 years and I can't remember) don't use it here. If you have a heat management problem in your engine compartment, it will cut the radiant heat from the exhaust system considerably.

Breakaway
04-30-2019, 11:07 AM
Often, these towers and tops in saltwater see pitting, rather than total anodization failure.

https://uploads.tapatalk-cdn.com/20190430/642ce1e202e88055e61f32c8528e9b42.jpg


Looks bad up close and if you are looking, but from the dock, if rinsed and kept clean, it looks fine.

My estimate for a top was based on pipework featuring post anodized welds, a radio box, rocket launchers, a fiberglass lid and built to fit me and my boat.

We need Pipefitter on this thread.

Kevin


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