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Corrosion resistance products

Posted: Sun Jun 21, 2020 3:27 am
by Boxboy
Hi all, been working ( well researching) on what path to take in the boat remodel I am working on ( well I have a guy doing the work) . I have the fuel tank out, acid washed the inside hull, burred out the pitting and tig filled them up. And now need to decided on if I should spray the inside hull / bilge with a coating, before we install the 2 new fuel tanks.
Anyways doing all this research and came across this comparison /study.

https://corrosion-doctors.org/Inhibitor ... -Spray.htm

It seems to mention all the ones that keep popping up here like boeshield t9, atf50 etc.


Other improvements I am doing to make the hull less prone to corrosion is adding bilge fans and ventilation as the prior design had zero air circulation. Also considering putting in a small anode (aluminum) in the inside of the wet area of the bilge to a frame member.

Re: Corrosion resistance products

Posted: Sun Jun 21, 2020 9:29 am
by Chaps
"Also considering putting in a small anode (aluminum) in the inside of the wet area of the bilge to a frame member."

Good idea

Re: Corrosion resistance products

Posted: Sun Jun 21, 2020 11:25 am
by Boxboy
Thanks Chaps.

On the subject of anodes can you have too much aluminium anode on your hull or is it more robust than being over zinced?

According to boatzinc webpage xcal you need 3 times as much zinc anode in weight than you do for aluminum.
https://www.boatzincs.com/anode_weight_calculation.html

I have these canard performance fins with long zinc anodes 3"x40" which I am replacing with aluminum but didn't want to get over aluminum anodes...


As for spraying the hulls interior seems a non water displacing film is best if you have a dry hull to spray like I do. But my best defense and prevention is forced air flow through the bulges and keep it dry...

Happy father's day to all.

Re: Corrosion resistance products

Posted: Sun Jun 21, 2020 7:11 pm
by Chaps
You can't overprotect with aluminum anodes, put on as many as you want with no harm done but putting on more than you need is pointless. Overprotection occurs when there is a major difference in galvanic potential between the anode and what you want to protect keeping in mind that the conductivity of the water is the wildcard. An example of that would be installing magnesium anodes on an aluminum boat that will be used in salt or brackish water, the anodes would go into hyperdrive waste mode (overprotecting). In clean fresh (low conductivity) water the magnesium anodes would be fine.