Underwater Screw Corrosion

[plewis]

While preparing the bottom my 2013 R29 Volvo D4 for painting I noticed that the 2 screws below the waterline of the 4 screws holding the exhaust thru-hull to in place were severely corroded - the entire head was missing on one and the other was 50% gone. The thru-hull was not bonded to the ground system, should it be and if not any ideas what is going on?

I'm probably not alone with this problem so a might be a good idea for all to have a look at those screws.

 

[Kevin Lamont]

While preparing the bottom my 2013 R29 Volvo D4 for painting I noticed that the 2 screws below the waterline of the 4 screws holding the exhaust thru-hull to in place were severely corroded - the entire head was missing on one and the other was 50% gone. The thru-hull was not bonded to the ground system, should it be and if not any ideas what is going on?

I'm probably not alone with this problem so a might be a good idea for all to have a look at those screws.

Hello,

We are currently bonding all of our exhaust thru-hulls even for the generator, I would recommend that you replace the damaged bolts and supply a bonding to the thru-hull. You can tie it into the port side bonding or any bonding buss on the transom. Hope this helps.

Thanks,
Kevin Lamont