Trim tab backer plate??

[sheboyganjohn]

On the Sea Ray I removed the very old and butchered trim tabs from the boat and picked up a used set of Bennetts. When I looked at the install procedure, it showed a backer plate. Since mine did not come with a backer plate I decided the easiest thing to do would be to fab some up with stainless flat stock. When I test fitted it, the tabs bind on the backer plate. Can someone shoot a picture of the actual alignment of the backer plate and the hinge? Or are these backer plates more then just flat stock?

 

[Scott Danforth]

backer plate is simply a flat piece of stainless. it is more of a shim. its about 1/8" shy of the knuckles on the continuous hinge

Tabman , can you help?

 

[sheboyganjohn]

That may be my problem. I was running it down even with the continuous hinge since I did not have anything to go off of. Does the backer need to help secure the hinge on tab in place or does it just hold the entire tab away from the hull? Just trying to figure out how critical the alignment is between the two. I can wait and see if Tabman chimes in.

 

[Scott Danforth]

I can take a pic tonight of the hinge on my boat if it helps

 

[dingbat]

Does the backer need to help secure the hinge on tab in place or does it just hold the entire tab away from the hull? Just trying to figure out how critical the alignment is between the two. I can wait and see if Tabman chimes in.

The backer simply takes up the gap between the offset of the hinge and the transom. Measure the offset of the hinge and go up a gage

Don't remember the exact thickness but I'm guessing 0.08" to 0.10" range.

 

[sheboyganjohn]

I can take a pic tonight of the hinge on my boat if it helps

That would be helpful. Thanks.

 

[sheboyganjohn]

The backer simply takes up the gap between the offset of the hinge and the transom. Measure the offset of the hinge and go up a gage

Don't remember the exact thickness but I'm guessing 0.08" to 0.10" range.

So, with the backer plate there should only be a small gap between the hinge and the hull, with no plate behind the hinge? I thought the backer plate was there to keep the hinge from rubbing on the boat? Just to be clear, the tabs I am dealing with are two piece and the tab just hooks onto the mounting plate to make a hinge. There is no, what I would call, traditional hinge involved.

 

[Tabman]

The backing plate is actually a little larger in height and extends below the hinge plate by about 1/8" or so. This provides a "bearing" for the curved part of the Tab to lock into. I would really recommend you replace it with an original Bennett Backing plate.

 

[dingbat]

In that case the tab is sandwiched (retained) between the backer and the hinge plate. Looks to extend just a tad lower than the hinge flange

 

[Tabman]

[No message]

 

[Tabman]

Yes, the backing plate has to extend below the hinge plate so the "knuckle" of the Tab can bear on it.

 

[Tabman]

Without the backing plate extending past the hinge plate the Tab will rub against the fiberglass as it moves, chafing it and will bind.

 

[sheboyganjohn]

Thanks Tabman and Dingbat. I now know how the backer plate should work. I was running the backer plate completely even with the tab bottom. Looks like it needs to run a tad higher but still act as the bearing surface. I will give it a shot with my backing plates one more time, if I cannot get the alignment correct, I will order some new ones. Unfortunately I have bigger fish to fry right now. Found a milkshake in one of the engines.