What wood to use for motor mount?

[FeelinMorgan22]

The boat is a Morgan 22. Motor is 6hp Tohatsu. See the photo of how the motor mount is set up.

The block of wood is attached to the mount by 2 screws which go all the way through the wood. Then the motor clamps on the block of wood. I bought the boat in this configuration and it seems to work well. I've noticed some splintering/rot on the wood block so I want to replace it.

What kind of wood would you recommend for this use case? Can I use "Southern Pine", which is readily available at my local Home Depot? Also, not sure if I should use "pressure treated" or not. Thanks.

 

[dlochner]

No to pine, too soft. White Oak or Ash would be good choices. Seal the wood with epoxy and paint or varnish to protect from UV.

 

[thinwater]

I used to worry about rot and would look to fiberglass and plastics for motor mounts. But I've had a few motors vibrate loose, and now the idea of an easily replaced, sacrificial layer that the motor can bite into is starting to seem like a good idea. For that set up, I'm thinking pressure treated deck wood might be perfect. It's not a heavy motor.

People laugh at this one because they are young girls, but I bet 50:1 that dad mounted the motor and they did nothing wrong. I feel for them. That could have been my daughter, and it would have been my fault.
Motor comes off

 

[FeelinMorgan22]

I used to worry about rot and would look to fiberglass and plastics for motor mounts. But I've had a few motors vibrate loose, and now the idea of an easily replaced, sacrificial layer that the motor can bite into is starting to seem like a good idea. For that set up, I'm thinking pressure treated deck wood might be perfect. It's not a heavy motor.

People laugh at this one because they are young girls, but I bet 50:1 that dad mounted the motor and they did nothing wrong. I feel for them. That could have been my daughter, and it would have been my fault.
Motor comes off

That's sort of what I was leaning towards... I can buy an 8ft board 2in thick 10in wide of pressure treated Southern Pine for $16. I could make a bunch of these identical blocks out of that. I understand it's not the ideal wood for the job but it would be easily replaceable and like you said I can really clamp into it.

 

[kappykaplan]

I can buy an 8ft board 2in thick 10in wide of pressure treated Southern Pine for $16.

Sacrificial or not, southern pine is still too soft, in my opinion. Doesn't matter how many coats of epoxy, etc., you put on it.

 

[FeelinMorgan22]

Sacrificial or not, southern pine is still too soft, in my opinion. Doesn't matter how many coats of epoxy, etc., you put on it.

I will try to find something harder in stock near me. I appreciate the input from everyone.

 

[jssailem]

Easily found at a box store is stair Tread. They can be soft or hard wood. It will be boards glued together to form a 12 by 36" board. $10 here in Pacific NW. Yo can get several pieces out of a 3 ft piece.
You can use for plywood. Get the B/C piece for the better glue. Or Exterior plywood. Most of the box stores will have small cut pieces they call "Project Cut".

@thinwater struck truth, that that wood provides a better group for the motor mount and that is serves like a zinc as sacrificial. It may outlast your ownership of the boat.

 

[Project_Mayhem]

I picked up a green 2x12 about eight years ago and have been cutting it down little by little for every boat. No issues so far. Much better than plastic. They do see water as the stern squats at WOT. Be sure to check the clamps of the motor every few minutes when you first install it. Then every 30 minutes, hour, etc. By the second or third outing, it should be secured. I had a motor go for a swim once because I forgot to do this.

 

[dLj]

An excellent choice is black locust. Should be available in the Erie area.

dj

 

[jibes138]

Why not use plywood? Just epoxy glue pieces together to get the thickness you want. It will be stronger than a pine board yet still some softness to let the clamps bite into it. Always attach a safety cable to your motor to prevent it going swimming.
Look at the transom of an inflatable boat, the industry has already perfected this solution.

 

[SFS]

StarBoard won't rot, or suffer from water incursion. Buy it once and never worry about it.