Hi again, just wanted to know if their was anything I can do apart from turn the battery off after use, to try and stop corrosion from happening around the screws (rear seat cushioning) which are on the back of my Quinnie.
Hi again, just wanted to know if their was anything I can do apart from turn the battery off after use, to try and stop corrosion from happening around the screws (rear seat cushioning) which are on the back of my Quinnie.
Turning your battery off is probably not going to do anything. Isolate the dissimilar metals using duralac or similar, and post some photos if you want some more details. Be warned though, there is a million experts here who know corrosion!!Originally Posted by sunnycoast62
yep. i'm a corrosion expert. you name it, i've had it corrode... andy is right tho. your corrosion is from the reaction between your stainless screws and the ally. remove the screws, duralac and replace.
fishing's as simple as 3 P's - patience, perserverance and PLASTIC!
Thanks for the info, so what your saying is to unscrew the screws that are holding the cushioning in place and coat screws in duralac and this will stop further corrosion?
Thanks very much for your help, do you know if BCF sells this product? how often should this be done.
yes. bcf sell it. about $35 per tube. you should only need to apply once. unscrew the screws and apply duralac wherever dissimilar metals are in contact. this should be done everywhere on your boat where stainless meets ally.
fishing's as simple as 3 P's - patience, perserverance and PLASTIC!
Hey thanks very much for your help, my boat is getting a new floor at the moment as the timber that was installed was the wrong type. Quintrex are replacing it, boat only 3 years old.
Thanks again for your help.
Warren
Would also be asking what "type" (316/304/?? and exactly where it was manufactured) of stainless fittings are installed.
For clarity, Duralec cannot stop the corrosion once it has stated.
It can only help prevent galvanic corrosion starting.
Once started the chemical reaction going on in between the paint and the aluminum (bubbling the paint and rapidly growing away from the screw) will continue unless the area is sanded and repainted.
Then look at the prevention methods.
Darren
Yep - what Darren said. - You will have to deal with the existing corrosion as well - or it will keep growing. Additional to using duralac around the screws- try and fit nylon washers as a barrier between the dissimilar metals.
Grinding, sanding, wirebrushing will all help - but it will come back. The only way to deal with the corroded areas completely is to sandblast the affected spots prior to repainting.
However, as a short term fix remove the paint covering the area that is corroding, wire brush using a stainless steel hand brush, then use aluminium cleaner or (acid wash). Do not repaint. You could brush some penetrol over the area as well - which will retard further corrosion. If you re-applied the penetrol every 6 months - it would stop the corrosion spreading further.
- This will do a reasonable job of slowing down the corrosion until you can have it fixed properly.
Also - check to make sure that there are no electrics earthed to the hull. By that I mean make sure there are no wires connected to anything - such as a screw or rivet that contacts any aluminium on the boat. Any such wires that are not isolated will form a circuit throw your hull which will greatly accelerate the corrosion process.
Mark
When I look at galvanic corrosion I see a tiny short circuited battery, remove the short circuit or the battery electrolyte (or both) and the galvanic corrosion will stop dead in its tracks.
I was out in a Quintrex bow rider the other day and it had nylon washers under the s/s press stud clips and no corrosion.
Also, as a fellow Quintrex owner I note that they put they earth the o/b -ve lead, -ve battery cable and main accessory neg to the hull with a bolt. I previously read on this forum that this practice may also have something to do with accelerating the corrosion issues the Quinnies have too....as Mark has also mentioned above.
http://www.ausfish.com.au/vforum/sho...-for-problems&
In any case, I recently removed the negs from the hull put them on a common -ve bus bar.
When I look at electrolytic corrosion I see a tiny electroplating plant, remove the external power supply and the electrolytic corrosion will stop dead in its tracks.
Fed, when you refer to the "external power supply", are you referring to a "stray" current?
No mate, I'm referring to the boat battery.
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