well,we're gonna cover some old ground here,so work with me guys...

aluminum parts-outboard brackets specifically,that's what we're gonna cover.
friday,i went to look at a job,it was a boat,owner was complaining the bracket was under water,and his engine was sitting very low as well.he wanted to see what i thought.i inspected it,it was clear the bracket was leaking water into itself,around the perimiter area.the inside of the boat told the story.the hold down washers,these were "sunk" into the transom,a good bit too.the bracket told another story-same bottom paint as the boat.the surface of the bracket was filled with erosions from the galvanic reaction that's been taking place,even better was the drain plug at the bottom of the bracket,the original aluminum plug was replaced with a bronze garboard plug...nice...transom failed a moisture test-meter was "pegged",the bracket,it appeared to be pourous from the galvanic corrosion that had been taking place.i'm writing an estimate for the boat now...

bottom line here is,do not paint aluminum products with copper based antifouling paint.these products require a tin based anitfouling paint,i use trilux.trilux is specifically for aluminum.painting that outboard bracket with the same paint you use on the boat is asking for trouble.it's gonna cause a huge problem down the road.there's more,if your rig is equipped with an outboard bracket,you need to have at least a 1" gap around the perimiter of the bracket and the copper based antifouling paint-this gap will not be painted-you need this,it matters...
if your boat is equipped with a bracket,and it's painted with the same paint on the boat,here's your chance to correct this,before it turns into a huge problem-do it now...

more on brackets:
if they're leaking at the perimiter flange area,the only way to repair this leak is to pull the engine(s) and pull the bracket-this will cure the problem.usually what happens is the bolts holding the bracket on,these sink into the transom,over time,causing the bolts to actully"back off",due to the core compressing-get what i'm saying water finds it's way in there.now,sea water,when it evaporates,salt is left behind,right.this salt,it wicks moisture,it actually prys the parts apart-result of the wicking.only way to cure this is to bite the bullet and do the job the right way-pull it all off.addign foam to the bracket will not increase the bouyancy of the bracket-sorry...the foam will only take up space.again,there's only one way to repair things,right
effects of corrosion-if the aluminum is eroded away,clearly it's been weakend,right,common sense huh.there's no way to repair this condition,besides,cutting it apart and welding in replacement pieces-pretty costly huh.
all this agrivation can be saved by using the correct antifouling paint...
remember this...

jawz, I believe you'll find that "ALL" TBT (tributyltin) based paints have been banned. Totally agree that copper based paints cannot be used on or touching aluminum running gear. I tried to buy some of the old Tempo clear spray that contained TBT. As I had contacts just about all over the world I tried many different countries w/o success. That was the best a/f paint for running gear regardless of what metal was under the boat. I used it on all 3 of my boats that had inboard propulsion. Nothing is as good as that stuff that I have found.

certain paints have been banned,trilux is not one of them...

Trilux is not banned but I think you'll find that Trilux does not contain TBT. From the International Paint web site:
The ideal Aluminum Bottom Paint, Trilux 33 a new tin-free antifouling formulated to provide safe, effective protection for aluminum boats, outdrives & outboards, or where a bright color or bright white is required. It is based on the latest Biolux® Technology, for improved control of slime and algae growth. It replaces Trilux and Micron 33. Trilux 33 is for use below the waterline on underwater boat hulls and parts in fresh, salt and brackish water and can be brush or roller applied.
Re the spray Trilux; the following was taken from the spec sheet:
Biocide: Cuprous Thiocyanate
Additives: Biolux (anti-slime technology)
"NO" TBT.

you're missing the point i'm making,let's try again here...

copper based antifouling paint is not to be used on underwater gear,or aluminum parts-it's a copper base...

now,i'm fully aware of the fact some paints are banned.trilux is not a paint that is banned.it's what i use and reccomend,for alumin and underwater gear...

Since we are on the topic...Jim do you use the spray for outdrives or brush them? It could be me and I will take the blame but it seems that one can of paint does not put nearly enough paint on the drive to last a season, or at least what I call a season. I applied in multiple thin coats the last two seasons but end up with horrible growth by July. I am typically in the water from mid/late February through the week of Christmas and put up a little over 200 hours. The boat gets used typically once or twice a week unless the weather doesn't permit us to even go for a boat ride down the bay. To me it seems that the paint wears off and I am left unprotected. It is not flaking or anything, there is no electrolysis or pitting anywhere on the drive.

jawz, I may be missing the point but you're not hearing what I am saying. Above, I said Trilux is "NOT" banned ! All I'm trying to convey is two things: 1) Trilux does "NOT" contain TBT. 2) TBT has been banned !
Agree ?

i like the trilux to be brushed on...seems to hold up better...
a small amount of slime does grow,but,it will easily brush off...

jim what would you use on the aluminum electronics boxes, and the helm box (i think thats what its called ) up on the tower ? couple sections peeled off right down to the bare aluminum. i wanna repaint them. i figure if i say rustoleum you'd cuzz me out.......lol

same as any other aluminum surface...chemical etch prime,epoxy prime,followed by awlgrip

That's what I figured, going that route this year. Growth as far as worms and barnacles on my running gear was awful last year...the one stretch i didn't sail for two weeks I couldn't get on plane in the bay. Didn't feel like diving in so had it short hauled and power washed.