common problem with outboard brackets !!

[jawz12]

i posted this on another site...

this is a common problem with the aluminum outboard brackets.the powder coating will get scratched or nicked from every day use,these surface defects will fill with water.the salt water will evaporate,the salt is left behind.this salt build up will wick moisture,actually prying the powder coat off the aluminum,leaving behind the bare aluminum.this bare aluminum will corrode.if the bracket has been painted with a copper based antifoulant paint,the problem is worse,it will cause a galvanic corrosion,due to the dissimilar metals-the aluminum will sacrifice itself to protect the copper-what you have done is create a battery !!!
if the powder coat has been damaged it needs to be repaired NOW !!! the way i reccomend to do this is by sand blasting the bracket,followed by "etch priming" the bare aluminum surface,followed by epoxy coating the surface,then finally painting the surface using a 2 part paint....
these brackets have water drains,these drains need to be pulled at the end of the season.water will collect into the bracket,due to condensation,etc...
there should only be a very small amount.if when removing the drains a large amount of water is present,you have a problem,and it needs to be repaired NOW !!! the problem will not get better it will get worse.water can and will enter the bracket from the inspection ports,as well as the edges where the bracket seats against the hull. these areas deserve close inspection !!
the bottom paint should never be against the aluminum surface,there should be a 1" gap between the bracket and the surrounding copper based bottom paint.the bolts securing the bracket to the transom should be seperated from the aluminum surface by using a plastic or nylon bushing washer.
check out the posted pics and you will see the end result.....
as you can see the bracket was pretty well filled with water-not a good thing !! the problem with the water is the weight and it's leverage-we've all used a pipe to turn something,to gain leverage,the water in the extended bracket acts as leverage.it can cause the scuppers to allow water to enter the boat,and eventually sink the boat-due to the boat sitting lower in the water...
if you've never removed the drains in your bracket-i highly reccomend you do so....
the bracket was sand blasted in a few spots,to determine the extent of the damage-the result of those spots being blasted are in the next post....

[jawz12]

this is the result of sand blasting the spots-it was discovered to be pourous,a hole actually blew thru when it was hit with the sand blast-the surrounding area was found to be pourous.there are a few cracks that were apparent after the blasting above the bracket zinc and the opposite corner of the bracket was found to be pourous.
in my opinion,these problems can't be repaired,the only repair is to remove the engines and remove the bracket-fill the holes with epoxy and matt over them with cloth,followed by installing a replacement outboard bracket...
again,if your boat is equipped with an aluminum outboard bracket,you need to check these things and correct them before they become a much larger problem down the line....

[jawz12]

the engine were not removed before blasting a few spots,the surrounding areas appeared to be questionable....the blasting was done to check a little further,as i've ran into this problem before....normally the engines are removed and the surrounding areas are masked off....take close note-the bracket was painted previously-the red primer is a tell tale
also note the bottom paint is against the bracket....

[jawz12]

here's the update on this rig.....
this is the boat that had it's bottom blasted-the other thread i started regarding sand blasting...this boat has had in total,water pumps in the engines as well as thermostats,the engines along with the boat have been winterized...the cockpit deck hatches have been recored-a very common problem with the grady white boats-they use cut off pieces of ply wood they're "laminated into the skin of the deck hatches with a mix of polyester resin and cabosil...these pieces of wood are not even marine grade plywood-the end grain has voids-no voids in marine grade plywood....that's why the gradys have a soft deck....the grady whites also use 3/4 ply wood on it's side to support the deck hatches-this wood isn't marine grade either-sad very sad
anyway....the owner wanted to get the bottom blasted and done up the smart way....
the new bracket for the engines has arrived...with the amount of hurricane damage in florida-everything has taken a hit !!!
the bracket is made entirely of fiberglass-a very high quality piece...there are no corrosion issues to worry about with the use of these brackets....
now remember,it's spring...time to paint the bottom,right??? DO NOT PUT COPPER BASED ANTIFOULING PAINT ON ANY ALUMINUM SURFACE_EVER !!!!!!!!!!
here's a few pictures of the replacement bracket....this boat will also have the thru hull transducer removed along with the 'ducer on the starboard side....i'll post up some pics of repairing the hole in the hull too !!!

[jawz12]

here's the rest of the pictures....

[Proheat]

Jawz- I have a bracket question-
First, I have a 1999 proline with a single aluminum (STAINLESS MARINE) bracket.
I was thinking of repowering and buying twin outboards. I know that I'd need a twin bracket, but my question is: have you had any experience with this brand and do the holes line up through the transom, or do you have to put new holes in and then fill the old ones?

Thanks
Barry

[matey1]

Jawz, wow on the bracket going away like that. my boat is a 2001 sportcraft w/ a bracket and i have checked it a couple of times and no water has ever been present inside it. this info here will keep me looking at it regularly though. glad i haven't had problems like that.

proheat, my guess would be if the new bracket for twins has holes init already it might be tought to have them match up. ifit comes without holes and you have to drill them perhaps you can align it with the existing holes to save having to drill new and plug the old ones.

[flatbottom]

pro that boat will move really well with twins

[Finesse]

That looks to be a SeaMark / Potter Bracket !!!
Nice stuff !!

[jawz12]

That looks to be a SeaMark / Potter Bracket !!!
Nice stuff !!

good eye !! i only use quality supplies-NO JUNK EVER!!!!!
for the record...i hate outboard brackets...