Transom Plate/Bracket Mount

[BigNiner19]

Does anyone have some good pics of a transom plate/bracket that they made or had made to slip over their transom to add extra strength support for that heavy motor hanging off? Below is a picture of what I came up with for my little boat, but I now have a 171 Mako Angler that I would like to do something similar to. The transom is really strong, so putting a plate to add strength sounds like a great preventative maintenence idea. However, this time I think I want to get a plate that hangs over the front, and over top the transom, and over the back for the mounting holes. If anyone has a picture of their's that would GREAT.

My only concern here, is that on the Mako, I can only access the TOP two mounting holes from the inside of the transom, so the plate would hang a little over the front/top of the transom and then down the back of it for the mounts. Any thoughts and pictures would be AWESOME.

 

[ondarvr]

Re: Transom Plate/Bracket Mount

What makes you think it's needed? If the motor is within the recommended range for the boat, then it's not needed, if it's not in the recommended range, then your on your own. If the transom is in bad shape, then it needs to be fixed.

If you want to do it because it looks cool, then a metal fab shop (or you) can bend one up easily.

 

[BigNiner19]

Re: Transom Plate/Bracket Mount

Whether a transom is strong or not. Adding some extra strength to an already strong transom is ONLY a good idea. I agree that if a transom is weak, doing something like this is NOT a fix. But mine is strong. Like I said...its something I've seen on other boats, and something I think would be a great thing to do to an already strong transom.

The motor I would be powering with is within the HP range the boat is designed for, but is also 116 lbs heavier than the motor previously on it. I'm sure someone on here has fabbed something up, or has more input on something related to this.

Cory

 

[ondarvr]

Re: Transom Plate/Bracket Mount

I actually have one on my jet boat, but it's there for a reason, the boat has been heavily modified and the plate is structural, plus it's aluminum.

The plate pictured does nothing, four slightly oversized washers would do the same thing. For the plate to add any strength it would need to be much larger and be bolted to the transom at the outer edges, not just with the motor mount bolts.

If your transom is already really strong like you said, then adding aluminum will do nothing, there is no preventative maintenance aspect to it. In fact you may run into problems by drilling numerous unneeded holes in it, each hole is an opportunity for water to get in and rot the wood.

People add plates like these to already rotten transoms in hopes of making it last another year or so.

Making one is easy, make a template or take accurate measurments, lay it out on the aluminum and cut it out. You can bend it yourself, or take it to a metal fab shop.

 

[tashasdaddy]

Re: Transom Plate/Bracket Mount

it also hides the early detection of problems.

 

[BigNiner19]

Re: Transom Plate/Bracket Mount

The bracket pictured is there for looks as much as it is there so that no washer "indents" from the torque and weight of the motor on the transom show up.

I'm talking about a bracket/plate thats goes from the front....over top...and over the back of the transom. This seemingly could ONLY add extra strength.

No extra holes would be added to the transom for this...simply the existing holes for the motor are used.

 

[tashasdaddy]

Re: Transom Plate/Bracket Mount

then do it. i just think they are extremely tacky, to me they say, my transom is weak, and i'm did want to fix it.

for strength, i have patched boats with 2 pieces of L shaped metal, one fits inside the transom and the lip, not quite all the way over the transom, the the larger, longer piece on the outside,with the lip over the transom. you then have the double "L" for strength, and the ability to tighten the motor completely flat to the hull, your design can not be fabricated to the exact dimensions, and allow for the compression of tighten. also use 3m4200 around the plate to seal it.

 

[ondarvr]

Re: Transom Plate/Bracket Mount

I know what you're talking about and what you're trying to do.

It would only add strength if the current transom was flexing, meaning that if the transom doesn't flex the aluminum will just be sitting there.

What you want to do is create an aluminum skin with a plywood and fiberglass core. Aluminum skinned cores can be very strong, but the aluminum needs to be bonded to the core for it to be of much value. This means glued (bonded) or bolted, more bolts (screws) will make it stiffer. This aluminum skin needs to be as large as possible covering as much of the transom as possible inside and out for maximum benifits. A plate just held in place by the current bolts will do very little, the transom clamps are very ridged already, so that area can't move. Whatever aluminum is used outside of the bolt pattern will do very little unless the metal you use is extremely stiff. If it is stiff, it will still only resist flex in one direction.
I know you want to incorporate a cap (U shaped), this will help, but again only if the current transom is flexing and only the actual cap portion will help, any aluminum extending down and out to the side will do nothing unless it's through bolted at the outside edges so that both sheets inside and out are tied together.

TD's method would add the same or more strength and be very easy.

 

[BigNiner19]

Re: Transom Plate/Bracket Mount

then do it. i just think they are extremely tacky, to me they say, my transom is weak, and i'm did want to fix it.

for strength, i have patched boats with 2 pieces of L shaped metal, one fits inside the transom and the lip, not quite all the way over the transom, the the larger, longer piece on the outside,with the lip over the transom. you then have the double "L" for strength, and the ability to tighten the motor completely flat to the hull, your design can not be fabricated to the exact dimensions, and allow for the compression of tighten. also use 3m4200 around the plate to seal it.

TD,

Could you please post up some pictures of this when you get a chance, so I can get an image. Thanks for the reply


Thanks for your input as well ondarvr..

 

[tashasdaddy]

Re: Transom Plate/Bracket Mount

i have a place here that fabricates these when ever i need them. 3/16 aluminum, or stainless.