Transom questions

[C Suskowicz]

Hey guys I am going to give it a go at replacing the transom on my Aluminum Starcraft.

I picked up 3/4 in marine grade plywood. What type of adhesive should I used to glue together and what kind of fiberglass epoxy to seal? Looking for product that will be easy for me to find if possible. I live in Maryland north of Baltimore

 

[Huntindave McCann]

"C",

I did this a few years back on my Starcraft. After removing what was there this is what I had. The new wood will need to fit between the outer skin and the center gusset, as well as the sidewall brackets.

The original thickness was designed to carry a two stroke motor and I was wanting to increase the thickness. I laminated three layers of 18mm Okume together for a total thickness of 2.125 inches. I laminated these by painting the mating surfaces with epoxy and clamping overnight.

Before installing it, I had to mill down the areas of the new wood where it had to fit to original thickness. (for the center support gusset and the side and lower brackets) Here you can see one of the areas I have marked which needs milled to fit between/behind a bracket. I've trimmed the outer edge to size and getting ready to mill with my router. I clamped a guide to the inside and left the scrap for router support on the outside edge. The edge of the transom facing you (which will be where the motor sits), has not been cut to size yet.

I also had to mill in counter-bores for the transom eyes as the threads were not long enough to accommodate the increased thickness and I was too cheap to buy longer ones. :>) All along the top edge was milled thinner to allow the top cap to be reinstalled as well.

Here is a shot of it all installed and ready to go except for installing the splash well.

Again, I used regular epoxy (NOT polyester epoxy) as my adhesive for the laminating process.

 

[Scott Farris]

I suspect that you will find two schools of thought. The guys who recommend encapsulating the wood in epoxy and those who recommend sealer/primer followed by a good enamel paint job. For a tin boat transom I'm in the non-encapsulated group because the wood is never going to be submerged for significant periods of time. The drain plug is below the wood as is any bilge pump arrangement if your leaving her in the water. This arrangement gives the wood plenty of opportunity to dry out after it gets wet. In more detail what Ive done is mount the wood to the aluminum with a silicone sealer (I stayed away from the 5200 in case the wood needed to be replaced in another 25 to 40 years). Do make sure the sealer is rated for aluminum as not all are and those that are not will attack the aluminum. This sealer layer was used because my old wolverine had lots of screws attaching the wood to the transom and I believe as the bolts are tightened the sealer is squeezed into all the fastener holes minimizing any water penetration at the fastener holes. It will also help prevent water from getting between the wood and transom when you drill the motor mounting holes. As far as gluing two sheets of marine ply together, like Dave I would recommend epoxy although I suspect any of the Titebond or Resourcinol waterproof glues would work well.

Have fun,

Scott