Trim Tab install questions

[Boatdrinks]

I started putting my tabs on my boat last night...got a set of standard Bennett 18x9's with the joystick control. The boat is a 21' 1986 Regal Majestic Cuddy 210XL powered by a 5.7L Mercruiser Alpha One. I got the port tab on last night (lots of finagling with swim platform brackets, transducers etc) and was just wondering about something. Due to my boat being on a bunk trailer, I did not put my tab on the very bottom of the hull. I spaced it up almost 1/8". Will this have an adverse affect on the tabs? Maybe I should have asked this before I did it...but I couldn't see any problem with it last night. Also...what is the best way to seal holes in the transom? It seems as though everybody swears by something different! I want these holes (gulp) for all the screws to be sealed good. Really good. The boat is 19 years old...and all the holes I drilled last night had nice dry wood shavings coming out of them. I really want to keep the old girl dry, you know what I mean? What is the best thing for this? Another thing...my transducer. I have heard of people mounting them to the back of trim tabs...but have never heard of the results. Do you know of anybody that has had any success doing this with a transducer? Hmmm...it might just end up being a trial and error thing but it never hurts to ask. Thanks in advance!

 

[Dhadley]

Re: Trim Tab install questions

Spacing them up 1/8" is too close to the bottom. Wont really hurt anything but they should be higher. How far up do the instructions say?

 

[Boatdrinks]

Re: Trim Tab install questions

The instructions say to: "Attach the mounting plates and trim tab with #10 x 1-1/4" stainless steel screws along the bottom of the transom." I am talking about where you screw the leading edge of the trim tabs on the transom. There is a part where you set negative incidence on the trailing edge of the tabs to 1/2" using a straight edge along the bottom of the hull. This step determines where you mount your trim cylinder.

 

[Solittle]

Re: Trim Tab install questions

Mine is about 1/8" up like you are doing.<br /><br />3M 5200 for the sealer.<br /><br />I have never seen a transducer mounted on a trim tab and think it would be a real problem - - rooster tail.

 

[rwidman]

Re: Trim Tab install questions

First, follow the instructions. If you are not clear, contact Bennett's customer service, they are probably the best in the business.<br /><br />Second, I never heard of installing a transducer on a trim tab and I don't think it's a good idea. Follow the instructions for the transducer.<br /><br />Third, there is no good reason why the trailer bunks should extend beyond the transom. See if you can adjust the bunks or the position of the boat on the trailer (while keeping tongue weight at the recommended percentage of total weight).<br /><br />For sealing the holes, 3M 5200 is considered a "permanent" sealer, it will be very hard to get the screws out if you ever need to. 3M 4200 may be a better choice. For either, drill the holes, then drive the screws in (without the tabs). This will cut the threads in the transom. Remove the screws. Then, put your choice of sealant in the holes and work it in with a small wire or tooth pick. Put additional sealant in the holes and on the screws and reinstall them (with the tabs this time). Remember, some of these products take seven days to fully cure.

 

[Boatist]

Re: Trim Tab install questions

My trim tabs are Bennett 24" by 12" cord each side. I mounted them up about 1/16 of an inch but 1/8 should be fine. I agree with 3M 5200 now but I used Silicone Seal on mine back in 1980. I did not trust the stainless steel screws so I used Stainless steel bolts with a big backing washer and Nylon lock nuts with a lock washer. Silicone seal on both side but mine is also a Aluminum hull. A little work to take the floor up on mine but I know It will last forever.<br /><br />When you mount your HPU make sure you get it level even with the bow up a little. Mine I had to reshim so fluid would not leak out when I raise the bow to drain water when cleaning the bilge.<br /><br />If you put your transducer on the tabs they will not work very well. First to close to the chims so not good for high speed. Second that 1/8 inch offset is going to create air bubbles and turblance at high speed.<br /><br />Mount your transducers on a transducer mounting plate.

 

[Boatdrinks]

Re: Trim Tab install questions

Thanks for the replies guys... Things are going well...the worst part about it all is the huge hole in my transom from where the transducer plug was passed through. Will have to patch that up with something...ideas there? As for the transducer...I am thinking of trying it out as a shoot through the hull application. I have nothing to lose there. I have read some strings about that subject and have a few ideas. I will let you guys know how it goes.

 

[Bondo]

Re: Trim Tab install questions

Thickened Epoxy would No Doubt be the Best Answer to Both,.... <br />Filling the Old Hole,+ Bedding the transducer to the Hull...........