Transom material questions

[Mmmjuice]

Hi all,

I am new to the boat community and just got my first aluminum boat (I believe it is a 1974 StarCraft marine 12’ sea scamp).

The boat looks like it is in great shape and my only questions relate to the transom. It looks like the last owners used HDPE to replace the transom wood and it looks like the aluminum plate out the outside wasn’t put back on.

My hope is to put an outboard on it in the 6-9.9 HP range, with that said, would you recommend replacing the transom material and and adding an aluminum plate? Is there anything else I need to consider?

 

[Mmmjuice]

I cleaned the boat today and gave it a more thorough once over. Wondering what the best way to proceed is.

I’d like to remove the HDPE and replace it with plywood or coosa and have it extend a bit below where it does now.

I’d like to replaced all the nuts and bolts. Then I am thinking perhaps I can drill the end of the crack to stop it from expanding, chemically bond it, and then put a piece of plywood or coosa on the outside. Then for extra supper perhaps one of those aluminum brackets/plates that protected the outside from the outboard clamp.

I can do basic maintenance and DIY - I am hopefully those crack discovery hasn’t ruining my dreams of getting on the water this summer. Any suggestions / materials / experiences would be appreciated, I don’t really have anyone locally to learn from at the moment.

 

[airshot]

If you have access to an aluminum welder, that would be best for the cracks. I would not trust any type of epoxy. I would recommend a wood piece on the outside of the transom, I don't like clamping to metal, most small outboards have little teeth or nubs that bite into wood to help keep the motor in position unless the motor is bolted on, which most small out boards are not.

 

[Mmmjuice]

If you have access to an aluminum welder, that would be best for the cracks. I would not trust any type of epoxy. I would recommend a wood piece on the outside of the transom, I don't like clamping to metal, most small outboards have little teeth or nubs that bite into wood to help keep the motor in position unless the motor is bolted on, which most small out boards are not.

 

[Mmmjuice]

If you have access to an aluminum welder, that would be best for the cracks. I would not trust any type of epoxy. I would recommend a wood piece on the outside of the transom, I don't like clamping to metal, most small outboards have little teeth or nubs that bite into wood to help keep the motor in position unless the motor is bolted on, which most small out boards are not.

I appreciate the suggestions, I’ll definitely do the wood piece on the outside - I should be able to measure the outline of where they used to have one.

I have a friend in the area that welds, I’ll reach out to him and see if he or anyone he knows would be able to help me with the weld.

 

[mbullen]

I agree with adding a pad to the outside. I would suggest being aware of total thickness of the two combined pieces, too.
The total depth shouldn't exceed the width of your transom clamps.
Usually around 1.5in.
The thickness of the inner yoke is usually dictated by the thickness of the top cap and/or corner braces.
Subtract that from 1.5-ish and one can get the required thickness of the outer pad.

 

[Mmmjuice]

I agree with adding a pad to the outside. I would suggest being aware of total thickness of the two combined pieces, too.
The total depth shouldn't exceed the width of your transom clamps.
Usually around 1.5in.
The thickness of the inner yoke is usually dictated by the thickness of the top cap and/or corner braces.
Subtract that from 1.5-ish and one can get the required thickness of the outer pad.

I’m glad you commented - I never would have thought of this, thank you for your insight!

 

[Mmmjuice]

Would you recommend replacing the transom first or getting the crack welded first? I’m just thinking maybe the welding will scorch the board underneath if I replace the transom first.

 

[thill]

I'm just curious... Is there actually a problem with the transom, besides the missing outer pad? Does it flex or bend or have any actual running issues at all?

The torn-out/cracked screw holes no doubt came from the rotten transom that was there before flexing. Welding them isn't a bad idea, but they shouldn't crack any further UNLESS the transom is still flexing with the current core.

That core might be tough stuff. You might have a great solution already, and not realize it. If it's strong enough, and it won't rot or change, that's a permanent fix. What drives you to want to replace it?

If it didn't have any structural issues, I would add an outer pad and run it like I stole it!

 

[MattA]

Im curious as well does the HDPE plastics flex with the outboard on or is it really stiff? I'm looking at replacing my transom with the HDPE plastics.