paint and corrosion problems

[g.stewart]

Hey guys,
I need some advice.My 2 year old 5.4 metre savage OSPREY alluminium is starting to get some small corrossion bubbles around most of the penetrations (rod holders, ladder mount, storm cover clips, running light, some welds etc) It looks like small rust bubbles but we know it cant be that.There seems to be a yellow primer under the white paint.All fittings were factory fitted.Th eboat is covered and extremly well washed down after each trip.
I am currently getting savage to have a look at but being a bit of a novice, i dont want to be snowed by the answer i may get.

Are any of you more seasoned boat owners have any idea what this might be? thanks Greggo :-?

[banshee]

Prety much par for the course with painted alloy hulls unfortunately,mostly it's the salt water corroding the raw alloy where the rod holder holes etc were cut,this then causes the bubling around the fixtures,the other alternative would be electrolisis,this is serious and is caused by dissimilar metals reacting with each other,not much you can do about the first one but the second one would need to have all dissimilar metals insulated from the hull.

[g.stewart]

Thanks for that advice banshee. Really appreciate the help. I am running dual batteries and must admit i have left the power cutoff switch on a few times and has sat for up to 6 weeks. If wired in properly , i dont see a problem with this but you never know.It will be interesting with what Savage come back with.The dealer who is handling the warranty claim says he has seen it in alloy boats but savage has never had a problem with it.
Will let you know what happens

GREGGO

[Seahorse]

see what paint was used. there was a paint company that had some etch primer problem. i saw a boat that paint was lifting. i had spoken to a painter who was painting tinnies, and he said that there was a problem. it was about 6-9 months ago

[ribbit]

I have just been thru this with my 5 year old stacer. Dissimillar metals is mostly cause so I found out. Stainless screws, nickel plated press studs etc all react against alloy, add salt water and you have corrison bubbles around all holes.
I have just resprayed boat in 2pack. When putting back together I have done the following to stop/ slow it in future.
1: Marine silicone in every screw hole before screwing in s/s screws
2: purchased plastic washers and put under all press studs and under washers on bolts going thru transom.Quinny and other now doing also so I am told.
3: cut spacers out of clears material for under rod holders etc
4: Used a product called Duralac on a lots of other holes. Meant to be great but is yellow and stands out a bit so I finished rest with silicone.

Make sure you buy proper marine silicone as it is Non acid based. Normal silicon will eat into alloy until it cures and this will lift paint badly.

End result is boat looks better than a new one.
Now just waiting on new 115 etec to arrive to finsih it.

peter

[lippa]

all said well, just make sure ya turn ya battery off

[btsah]

Thanks for the great info everyone, my mate has similar problems.

Cheers
btsah

[g.stewart]

Thanks guys for all your feed back.Appreciate your ideas what caused problem.I had call from savage late yesterday and they were terribly concerned about the issue and want it fixed pronto.
They told my dealer that they wanted 2 quotes from local reputable panel beaters to completely strip the boat back and respray in 2 pak.If they werent happy with quotes the boat is to be sent back to savage in Melbourne and the strip back and respray will be done in factory.
You cant ask for much more than that and i commend savage for not walking away from problem.
once again thanks everyone for imput.
greggo