Antifoul paint on Suzuki DF300

[rib850]

Hi
New forum member, boating on River Medway.
I would be grateful for anyone has any thoughts or experience applying International Trilux 33 to the engine saddle bracket and bottom of skeg on an outboard.

I have a Ribcraft 850 sports fitted with Suzuki DF300hp. Both supplied new in January 2011. I applied 2 coats of Trilux 33 to the engine saddle bracket and skeg in March 2011 (underwater parts only and lightly sanded with 240 W&D before application) The boat was supplied with a coat of International Interpeed Ultra on the hull. In July of the same year I applied 2 fresh coats of Ultra to the hull and within 12 days the bar anode on the engine bracket was half eaten away and white deposits formed on all underwater engine stainless bolts. After replacing the anode the anode appeared to corode at the normal rate. The same has happened again in May of this year following a fresh coat of Ultra antifouling to the hull only. The 2 trim rams also corroded enough to cause oil to leak from the cylinders.
The boat has been returned to Ribcraft. Suzuki have authorised replacements under the warranty for these rams and seals and Suzuki technical department have looked at the boat and say that it is the Trilux33 antifouling paint on the saddle bracket that is causing the problem.
Trilux33 is the recommended paint by Internation for aluminium outboard / outdrive engines. Has anyone experienced this problem before? or can suggest a reason / solution
Many thanks

[behavin]

interesting

i have just had a complete engine rebuild of a df250 after the swivel bracket and lower leg unit have corroded away.

2 years ago i had the main tilt ram corrode through like someone had drilled a hole in the barrel.
my ideas were that i had a stainless skeg guard on the bottom as the skeg was damaged from a previous owner so by me putting it on it gave the skeg the shape again.
after i changed the trim ram the new one came with a bonding wire that connects to the main lower anode, and whilst doing this i did also use black trilux antifouling on yellow etching primer as all recommended by international.

my engine is now back together this summer with a new alloy skeg welded on and primed and painted with black enamel but the trilux remains on the trim units.

its had all anodes replaced and looks good but now you have me worried about the remaining antifouling

as to your problem...is there a gap between the interspeed and the engine mounts ? i think a 2 inch band is the normal

sorry i cant help any more

[rib850]

Thanks for your input on this.
Like yourself I applied the Trilux as recommended by International Paints. I have applied this to a previous Mercruiser outdrive and a Marina outboard without any problems over several seasons.

My boat was supplied with antifouling painted up against the engine saddle bracket, when i first experienced the problem last year I cut this back to create a 40mm gap and thought I had cured the problem until the hull was antifouled again this year.

First sign I get of the problem re occuring is the stainless steel bolts on the engine start to get a white oxide covering, I know then that the anode has been eaten away. Keep an eye out for the white stuff and if you dont see it you may be ok.

My corrosion problem may turn out not to be the paint but a leaking current in the wiring!.

[behavin]

yes agree that there could well be a bad earth somewhere within the engine loom.

i switch all off with only 2 bilge pumps and the fuel flow meter remaining live,.......

how do you find a bad earth ??

[chewy]

Bell the earths out.