Trim tabs

[Jrando305]

Have some damage to my port side trim tab, possibly electrolysis. Checking to see if the tabs are bonded or can I just remove the screws from the transom and replace the bad tab

 

[sgeary]

The trim tabs are not bonded to the boat. The round zinc that is attached to each of the trim tabs is the only protection they have from electrolysis.

 

[scross]

Are you using, and regularly changing, these zinks on your trim tabs? We use the R3 size.
https://www.boatzincs.com/rudder-sizes.html
Our trim tabs, rudder and prop are painted with Pettit zinc barnacle barnacle barrier as needed.
After eleven years, six of those in salt water full time, we have had no electrolysis issues even without the trim tabs being bonded.

 

[YukonRon]

I just had my boat hauled and did the zincs for the first time. (It spent a lot of time on the trailer or in fresh water lakes in Yukon) My trim tab zincs were almost gone. The dealership sent me R3 zincs for the trim tabs, but I could tell from the residual circles that they are smaller than what was on there before. The factory or previous owner must have used R4s in the past. I will be keeping a close eye on them and probably switch back to R4s next time.
As an aside, keep those trim tabs stored in the up position and keep the actuators clean. I forgot to raise mine on returning to the marina once, and had considerable growth on the rams. I went for a swim on our next anchor out and thought I got them really clean. As soon as I retracted them, there was hydraulic oil sheen on the water. I had to replace both actuators. The installation instructions said NOT to bond them to the rest of the boat's bonding system.

 

[Jrando305]

Thanks for the answers, I did not have zincs on my tabs so I have some minor damage, might change out to a longer blade

 

[BB marine]

Thanks for the answers, I did not have zincs on my tabs so I have some minor damage, might change out to a longer blade

Bennett does not recommend bonding the trim Tabs. Bennett does not require anodes to be installed to the planes if used in fresh water. Bennett does recommend the use of anodes for protection in salt water or brackish. What ever anode material you use make sure they are all the same material. The factory uses zinc material for prop and Divers dream, Side power uses aluminum alloy anodes. The prop and Divers dream are bonded. The thruster is not. The question is what material anode should you use on the non-bonded trim plane? Does it matter? I have always used the boat in fresh water and choose to use Aluminum alloy. I am now in salt water and will continue to use aluminum alloy. Using all the same material anodes.

The C26 and C28 have the same size trim tab Planes. The installation is the same also. The next size tabs 18 X 12 will fit and will add additional stern lift. I installed the 18 X 12 planes without modification other than epoxying the old screw holes and drilling new. If you are changing the planes I believe you will be happy with the larger 18 X 12.

 

[Jrando305]

Thanks for your helpful insight. I will most likely replace the tabs with the larger ones that you recommended

 

[Eric R]

Thanks for your helpful insight. I will most likely replace the tabs with the larger ones that you recommended

I did this last summer and would absolutely do it again. I upgraded to the Bennett Auto Trim Pro system at the same time. Something I would also absolutely do again.