I would appreciate help with my Aluminum hull prep and refinish steps

[halas]

Re: I would appreciate help with my Aluminum hull prep and refinish steps

I always thought that the best finish for aluminum in terms of corrosion protection is the natural oxides that form on bare aluminum. Its when saltwater gets under paint through chips or scratches that saltwater gets trapped, and with the lack of oxygen, starts eating the aluminum away. I do not boat in saltwater now, but when I was in the Coast Guard, I boated on both the Great Lakes and the Gulf of Mexico. The 41' UTB that has been the standard workhorse in the Coast Guard for 30 some years is aluminum hulled. Here in the Great lakes, they are painted white. In saltwater environments (and they sit in saltwater as opposed to being trailered), the aluminum is left bare. Also, all of the newer CG boats that are aluminum, i.e. the 25' and the 45', etc are left bare. So, if your primary reason for painting is corrosion protection, IMHO- skip it. If you desire paint for its appearance, then others can help you, as I am no expert.

I agree with that 100%. Also would like to add that the oxidation formed on the aluminum can be good base for paints. Lots of time the old chalky paint is confused with aluminum oxidation. The old chalky paint should be removed before painting but not necessary the actual aluminum oxide.
Shiny new aluminum should be etched because it is too smooth for paint to adhere. Oxidized dull aluminum surface will however take paints without etching due to the porous surface already existing.

 

[halas]

Re: I would appreciate help with my Aluminum hull prep and refinish steps

Don't get me wrong guys, I appreciate the "do it cheap" methods, but this boat will be used primarily for the intracoastal and flats, so I'm worried about long-term corrosion protection more-so than "Wow, that boat looks good."

And I'm sure a lot of guys got good looking finishes done cheaply, that lasted, on freshwater lakes. It seems like I read about them a lot here on iBoats, but unless people specify that theirs is used 100% in the salt water, and has been for years, I really don't think I should take the "done it cheap" advice.

I'm calling around paint supply stores, and they're giving me the "never heard of roll and tip method - our paints are spray on only" deal that has me wondering if I should avoid their paints altogether, or if this is common with roll & Tip usage?

I would stay away from high gloss paint because it will make the inherently uneven aluminum hull look cheap. While high gloss will look awesome on fiberglass or steel it will show the thin aluminum boat for what it is.

 

[sschefer]

Re: I would appreciate help with my Aluminum hull prep and refinish steps

I'm going to give you the best advice you'll ever get on this subject. No, actually Yacht Dr. already did that... O.K. I'll throw my .02 in anyway... LOL..

Aluminum is such a great material for boats because it will form it's own naturally protective oxidation. None, I repeat None, of the custom Aluminum boat manufacturers paint except possibly to add a shear line band for customer appeal. Most all of your production Aluminum boats are painted but it's not because they need it, its strictly to help generate sales.

Since the sides of yours are already painted, just scuff sand it and shoot it the same or a similar color. You can use Rustoleum since your base is already bonded to the Al below it.

On the bottom, just leave it bare Aluminum but you can polish it out if you want to make it look like new.

If you need to get rid of those stripes, get a rubber pin stripe eraser for your electric 3/8 drill motor at your local paint store. It'll remove them faster than any chemical you can legally buy.

Will this all hold up in Salt Water?????? Darn straight it will..

 

[fisherguy123]

Re: I would appreciate help with my Aluminum hull prep and refinish steps

I'm going to give you the best advice you'll ever get on this subject. No, actually Yacht Dr. already did that... O.K. I'll throw my .02 in anyway... LOL..

Aluminum is such a great material for boats because it will form it's own naturally protective oxidation. None, I repeat None, of the custom Aluminum boat manufacturers paint except possibly to add a shear line band for customer appeal. Most all of your production Aluminum boats are painted but it's not because they need it, its strictly to help generate sales.

Since the sides of yours are already painted, just scuff sand it and shoot it the same or a similar color. You can use Rustoleum since your base is already bonded to the Al below it.

On the bottom, just leave it bare Aluminum but you can polish it out if you want to make it look like new.

If you need to get rid of those stripes, get a rubber pin stripe eraser for your electric 3/8 drill motor at your local paint store. It'll remove them faster than any chemical you can legally buy.

Will this all hold up in Salt Water?????? Darn straight it will..

I beg to differ with you sschefer......this was taken today at a marina of a boat that this guy bought from Florida at a good price. It was in the water there for about 5 years not used . As you can see even marine grade aluminum does corrode without treatment.

 

[halas]

Re: I would appreciate help with my Aluminum hull prep and refinish steps

I beg to differ with you sschefer......this was taken today at a marina of a boat that this guy bought from Florida at a good price. It was in the water there for about 5 years not used . As you can see even marine grade aluminum does corrode without treatment.

Not to change the subject but do you have picture of the whole boat. Just curious it seems like an interesting vessel. What make is it?

 

[fisherguy123]

Re: I would appreciate help with my Aluminum hull prep and refinish steps

don`t have a full picture ....but a guy at the marina said it`s a "MARINETTE" about 32 ` and about 30 years old, 2 big gas engines in it. The shipping cost more that the price of the boat. Owner apparently is going to sell for parts and scrapmetal if restoration is too costly. Props alone should be worth something...about 20'' bronze. Would have been nice to see this new and running....a real screamer I bet!!!

 

[sschefer]

Re: I would appreciate help with my Aluminum hull prep and refinish steps

Fisherguy 123 --- What I said is true. The natural oxidation seal that forms on Aluminum provides far more resistance to corrosion than any paint will ever provide. Can you imagine what that boat would look like if it was steel or fiberglass and hadn't been maintained for 5 years.

What needs to be brought to light is that boats need to be maintained properly if you want them to last. Your post brings that fact out clearly by showing what happens to a boat that is neglected.

 

[Starman8]

Re: I would appreciate help with my Aluminum hull prep and refinish steps

For stickers, decals, and the residue on aluminum, all it takes is a blow dryer set on high, then use orange Goo-gone, then wash it all with a diluted vinegar solution..............works all the time.

Not going to comment on below salt water applications, BUT

I used an orbital palm starting with 40g thru 120g, and guess what, RUSTO clean metal Primer, 4 coats, then 3 coats Rusto oil-based enamel, roll and tip, and she looks great, and as time progresses, durable.

 

[fisherguy123]

Re: I would appreciate help with my Aluminum hull prep and refinish steps

http://forums.iboats.com/showthread.php?t=455022 saw this thread today......this is Alodine treated aluminum ..the stuff is used widely in aircraft refinishing you might contact the poster to see how well it held up...here is more info on it http://www.chemical-supermarket.com/product.php?productid=364

 

[sschefer]

Re: I would appreciate help with my Aluminum hull prep and refinish steps

The product is Alodine 1201, I use it often. The application process is not as simple as it sounds but manageable if you're willing to take the time. It completely eliminates the need for a primer.It's a chromatic conversion process similar to that which occurs when Zinc Chromate primer is applied but without the Zinc to act as an annode. The difficulty lies in getting the surface prepped properly. It must be thoroughly etched with all mill slag removed then cleaned followed by a detailed scrub with deionized water or you will get streaks and splotches where the conversion does not occur rendering it a wasted effort. It's not uncommon for it to take more than one attempt to achieve a useful level of conversion. I've done a few outboards that were destined for Salt Water using Alodine. Merc does it at the factory.

 

[Yacht Dr.]

Re: I would appreciate help with my Aluminum hull prep and refinish steps

Not to change the subject but do you have picture of the whole boat. Just curious it seems like an interesting vessel. What make is it?

I agree..There is alot of bronze skegs/props and rudders on that thing..Its alum ?..

Trim tabs dont look worked up..under the bottom paint looks goodish.

Im sure thats a sea slug..not a raped ape ..

I as well would like pics of the whole boat..

YD.