Time to rebuild the transom. Questions

[Suzn]

Hi guys!

So I'm at the point of rebuilding the transom on this rebuild and after scanning the site for more info I have a few questions. The old one is pretty rotten, the bolts had sunk in well past where they should be.

Looks like the old transom is 2 in thick. Is it best to use layers of my leftover 1/2 in marine ply or buy something thicker to sandwich together? I hate the thought of having to buy a full sheet of marine ply just to cut out a few triangles.

Next, the boat mechanic that I found suggests thin pieces of aluminum on the front and back of the transom. I can get this where I work so no problem there. I just wondered if it would hold the moisture if it had it on both sides? I could be overthinking that.
Do I have to glass it or can I simply coat it with some resin? I wouldn't go thick on resin here because I don't want it to crack. I'd really like something other than resin to make it waterproof here but I dont know what. Honestly, I wish I could use some sort of thick plastic instead of wood all together. I just thought of that and haven't researched it at all but what do you think?

Oh and I bought a new used motor..75h Evinrude to replace the 70h Johnson. There are some problems with it that likely would have left me stranded on the lake. It's a 24ft Lowe pontoon. And when I can figure out how to shrink the photos from my phone I'll post pictures.

 

[Scott Danforth]

4 layers of 1/2" glued together with tite-bond III or 2 layers of 3/4" and a 1/2" layer glued together with tite-bond III, or 2 layers of 1" glued together with tite-bond III

then seal with old-timers wood sealant.

plastic doesnt have any structural capability

 

[Suzn]

Thanks Scott! I just found this thread so I see that plastic is a no go.
http://forums.iboats.com/forum/boat-...om-replacement

I just measured my half inch Marine ply to see if it was a true half inch and it is so I'll be using that. And it looks like people have suggested in the thread above to Glass it. The bottom of this transom is going to be below the waterline and I'm a bit concerned about the polyester resin that I have used for the floor being used in a below the water situation. Is it good enough? I cannot get epoxy resin here where I live, I'd have to order that most evil expensive stuff. Lol
But seriously, do I need to order it for this?

Wait.. I see that you suggested the old timers solution. Is that stuff going to be better for below the waterline?

 

[sanity1676]

Bondo polyester resin is what I used on my jonboat. Found it at home depot. Like 12 bucks. Layered regular 1/2 inch untreated plywood, glued 3 layers together, let sit 48 hours under some weights, then slathered it THICK in polyester resin. I used gorrilla glue instead of tite bond. Make sure your wood is clean+dry. Also keep water AWAY while you work with resin. If it turns cloudy from water exposure, you gotta scrape down and resin spread again usually.

 

[ahicks]

Susn, I just replaced the transom on the '99 boat I did. I used cut outs/leftover ply from the flooring project as you are considering.

Also, would like to note no preservatives of any kind were used on the original transom, which was still in pretty decent shape when I removed it. Point being, if it can last nearly 20 years with no preservative, failing to see why I would want to bother trying to make it last even longer. There's a good chance anything I did do would not work as well as nothing!

 

[Suzn]

Susn, I just replaced the transom on the '99 boat I did. I used cut outs/leftover ply from the flooring project as you are considering.

Also, would like to note no preservatives of any kind were used on the original transom, which was still in pretty decent shape when I removed it. Point being, if it can last nearly 20 years with no preservative, failing to see why I would want to bother trying to make it last even longer. There's a good chance anything I did do would not work as well as nothing!

Thanks ahicks! I'm afraid using this resin and glassing it would potentially hold water in if it gets cracks in it. The old one is pretty rotted out but it doesn't look like it had anything on it either. I'm not going to worry too much if it rots out again I guess because it's not that difficult to replace.

 

[Suzn]

Bondo polyester resin is what I used on my jonboat. Found it at home depot. Like 12 bucks. Layered regular 1/2 inch untreated plywood, glued 3 layers together, let sit 48 hours under some weights, then slathered it THICK in polyester resin. I used gorrilla glue instead of tite bond. Make sure your wood is clean+dry. Also keep water AWAY while you work with resin. If it turns cloudy from water exposure, you gotta scrape down and resin spread again usually.

The resin I bought had better be a few steps above Bondi resin. For the floor boards I paid 150.00 bucks for a 5 gallon bucket and am on my second bucket. I got it from a company that specializes in aircraft builds. I did see some resin at Lowe's that was specific to marine resin applications but I couldn't find a reference to epoxy anywhere on it and it only came in one gallon containers, 40 bucks. I knew I was going to need a hell of a lot more than a gallon to get underway. Thanks for your response.

 

[Suzn]

Oh hey.. I have pictures! I created a Facebook page to kind of document my rebuild. It's here..

https://www.facebook.com/Pontoon-Rebuild-323899054729502/

 

[EchoNovember]

You can use Coosa board if you don't ever want to deal with rot again. However, it's about 3-4 times more expensive than marine ply with a couple coats of epoxy. It's stronger than the ply, though, and will last pretty much forever, but make sure you cut it right or order a custom cut piece that you are 120% is correct. It's really pricey stuff.