Powder coat, Paint, both or leave it bare??

[kanuckle head]

Making some Aluminum stuff for my boat just would like some input on the best way to finish a custom made Alum. accessories for my boat

I have tried powder coating, but that shiz is porous & not a true protective coating. I know, for a project I did before looked like crap after a year in the salt environment, all that work for nothing!!!!

Have tried painting also, using a good etching primer as a first coat. But one nick & the cancer can start
My buddy saw that my outboard pod started to pit corrosion after one year of use. He powder coated his pod but added a quality epoxy over top the powder coating & looked great after a few years till he sold his Grady, may still look great but I'll never know

I know if the right alloy the corrosion will be minimized as a bare finish, but I don't know if I like the faded dull Alum. look............I know one thing, oxidized alum. is bearable compared to coated alum. with Cancer spots!!

Pls give me the your input
Thanx

Kh

 

[Sculpin]

Hey Len,
Have you looked into anodizing?
Cheers,
John

 

[Finished Business]

suprised that powder coating didn't hold up in the salt...not sure about the porousness of it, I always thought powder coating layed on pretty smooth.

keep that welder warm! I'm hoping to be back on track sooner than later

Not sure if Aluminum acts like Stainless but a fine polish keeps stainless from corroding. Probably be pretty expensive I'm thinking...

 

[Sculpin]

suprised that powder coating didn't hold up in the salt...not sure about the porousness of it, I always thought powder coating layed on pretty smooth.

keep that welder warm! I'm hoping to be back on track sooner than later

Not sure if Aluminum acts like Stainless but a fine polish keeps stainless from corroding. Probably be pretty expensive I'm thinking...

I think this falls under the lines of what Kevin on AAB keeps talking about with getting the factory mill scale off. I sanded my rear deck pedestal seat platform before I put the non skid on it and the outer edges that did not receive paint look like the day I sanded them (almost a year ago).

 

[kanuckle head]

Hey Len,
Have you looked into anodizing?
Cheers,
John

My biggest problem on anodizing is the all welded items have to be the same alloys including the weld wire or rod, or else the anodized finish will have different shades
Plus can't find a local facility with large enough tanks that can accommodate my project footprint @ 40"x 50"x 8'6"

 

[kanuckle head]

suprised that powder coating didn't hold up in the salt...not sure about the porousness of it, I always thought powder coating layed on pretty smooth.

keep that welder warm! I'm hoping to be back on track sooner than later

Not sure if Aluminum acts like Stainless but a fine polish keeps stainless from corroding. Probably be pretty expensive I'm thinking...

SS would B the shiz but must B 316 cuz 304 will eventually rust
But the price of $30.00 per ft compared to alum. @ $2.50 per ft in the same 1.9 OD except the alloy is sced. 40 & the ss is light gauge @ .060

Powder coating is quite porous, the powder adheres to the material electronically then is baked on. Too hot & the melted powder will run, too cold & the micron powder beads barley stick together, under the microscope looks like marbles stuck together

 

[Sculpin]

My biggest problem on anodizing is the all welded items have to be the same alloys including the weld wire or rod, or else the anodized finish will have different shades
Plus can't find a local facility with large enough tanks that can accommodate my project footprint @ 40"x 50"x 8'6"

What are you building?

 

[kanuckle head]

What are you building?

Radar tower/over head support for my 2ft x 8ft extended FG roof

 

[wolf]

There is this acid wash stuff that the guy who did my radararch/rocket launchers when he was all done put it on and then washed it off and still looks good today i dont know what it is but cool stuff...

 

[gunnerlove]

There is this acid wash stuff that the guy who did my radararch/rocket launchers when he was all done put it on and then washed it off and still looks good today i dont know what it is but cool stuff...

Alodine, which is a surface chromate conversion. It usually has a gold/ green tint to it.

 

[tykkyt e blue]

Ooops - Try the folks at Huson Powder coating - they acid wash, then primer and top coat with polyster... It has worked well for me many times

 

[Canso]

a friend polished his jet boat then used Sharkhide.
its only been a year of fresh water use but still looks good.

anyone use this for boats in the chuck?
http://www.sharkhide.com/

 

[wolf]

Alodine, which is a surface chromate conversion. It usually has a gold/ green tint to it.

No it made it look like shiney new alum cleaned it up and was a and looked like BRAND new alum I dont know what it was but the guy who did the work for me and others is ward bohn of bohns sheet metal he does a lot of work in sooke here and and is a wizard and figuring angles out thats for sure.

 

[Drewski Canuck]

Corrosion is the gift of the sea. Only real thing to do to slow it down is to ensure that you have really good annode protection. I am guessing you have a fibreglass hull, so you cannot get protection for your tower from the an aluminum hull with annodes. An Aluminum pod though should have some annodes on it. Painting with a zinc rich primer raises the concern that you would in fact inhance the corrosion by introducing a dis similar metal for the electrolisis, so really, it is a great question to ask, but one that there is no easy solution. Only thing I can think of is a baked on finish of a Plastic Paint, or a 2 part epoxy paint system that will be very scratch resistant.

goota love that ocean!!!

Drewski

 

[KV1]

Only Option

The best thing to do without argument is 1.Chemical Acid Etch 2.Alodine 3.Zinc Chromate or Now Chromate Free Primer 4.A good quality epoxy paint (Endura). The finish will last for years and corrosion has no way of penetrating unless gouged with a rock or something right to the bare alluminum.

Follow all instructions on products and never mix metals IE stainless and alluminum this all comes from aircraft maintenance procedures and I can assure you they still look good after 50 years. It sounds harder than it is and all supplies can be obtained locally. FOLLOW THE MANUALS AND LABELS.

 

[Ish]

I am in the auto body business and have to second what KV1 suggests. Not enough people follow the manufacters instructions and this is what most often causes problems.