Do I need to have 3/4 ply on the back of the transom where the motor meets the hull??

[NAVY LIFE]

I am going to be putting my boat back together an have seen a lot of pictures with
plywood in between the motor and the hull. Is the necessary or added support??
What are your thoughts and if needed how to connect to back of transom?

 

[Georgesalmon]

Re: Do I need to have 3/4 ply on the back of the transom where the motor meets the hu

That extra plywood is usually the result of someone trying to reinforce the transom because it is rotted inside. You should not need it on a good solid transom.

 

[boatnut74]

Re: Do I need to have 3/4 ply on the back of the transom where the motor meets the hu

Is your boat a tinny (aluminum) If it is alot of them came with that plywood piece. Some of the guys here will leave it off since it is always in contact with the water and can lead to water intrusion into the transom. It's your call on what you want to do.

 

[robert graham]

Re: Do I need to have 3/4 ply on the back of the transom where the motor meets the hu

If you're wanting to reinforce or spread the load across more of your transom. then maybe about a 3/8" or 1/2" aluminum plate mounted on back of transom....plate to be several inches wider and deeper than your motor bracket. But if your transom is O.K. as is, maybe don't really need a plate?

 

[waterrat828]

Re: Do I need to have 3/4 ply on the back of the transom where the motor meets the hu

I thought the main reason for having a plywood board, is to reduce vibration and engine noise transmitted to the hull, and possible unwanted loosening of the motor mount clamps, from engine vibration.

 

[Bob_VT]

Re: Do I need to have 3/4 ply on the back of the transom where the motor meets the hu

It is normally fairly thin and bolted with the engine bolts. I have used a heavily coated piece of plywood. Yes it does cut back on vibration and prevents the thinning or wearing of the aluminum hull which is thin and soft.

I have in the past seen transoms that appeared as if the metal was hammered paper thin and worn. I would suggest using it. 3/8" would be fine since it is a protection/wear surface.

 

[jb93]

Re: Do I need to have 3/4 ply on the back of the transom where the motor meets the hu

What about a sheet of 1/4-3/8" UHMW plastic? UHMW is often used as a wear/vibration plate in heavy equipment. It has very good abrasion resistance, impact strength and no moisture absorption. Perhaps a better no-rot option if it is just for dampening and protecting the aluminum hull from wear? You can pick up a 12" x 12" sheet that is 3/8" thick for $15-25. It comes in black and white as standard colors. I think the white could get dingy over time and black would probably stay looking clean.