Does anyone know how to redo the transom on a 77 Venture bass boat

[Cgranado]

Hello I'm new to boat ownership cause a couple of weeks ago i got a wild hair up my butt and decided to buy a boat to fix up so that i could take my boys out fishing. Now as i have been cleaning it out and redone the wheel bearings and seals I'm ready to attack the boat it self. Now I'm not fooling myself this baby needs some work. From what I've read so far it's gonna a be a bumpy ride but i was hoping you all could help. I took a look at the transom yesterday and i am going to need to replace it, it is completely rotted out, does anyone know about how to go about it????????? . Any help would be great.

[hookahawg]

My buddy and I rebuilt the transom on a 1985 tidecraft a few years back. It was a 16 ft boat with a 70 hp on the back. I don't know if I would tackle anything bigger than about a 150hp simply because of the increased demands on the transom as engine weight goes up.
We carefully cut out and removed the outer layer of fiberglass on the transom so as not to compromise the inside structure, and it's just plain easier to work from the outside than the inside ( believe me, we've done both..!! ). Take your time when cutting out the back section as you will want to 're-laminate' it back in once you replace your plywood. You can then paint or gel-coat 'pinstripes' over the joints for a clean finish that will keep evidence of a repair to a minimum.
Make sure you get ALL the rot out and clean ALL surfaces properly before you try and re-glass, as you'll have problems with your new resin and/or cloth adhering to your existing structure.
Figure out the thickness of marine plywood needed and rather than using 1 thick piece, laminate 2 or more thinner sections together using a sheet of resin soaked cloth in between each layer. After each coat, lay a sheet of plastic on wet fiberglass and using a flat edged spatula or paint roller, remove air bubbles. Remove plastic sheet once resin has cured. Fiberglass resin will not bond to plastic. Then coat the whole assembly in resin to waterproof. Remember to consider the original thickness of the transom so that when you reinstall your outer skin, it's not sitting higher than the surrounding outside surface. Let cure, then 'rough up' the face that will be placed against the inside surface of your transom. Mix up some more resin and coat both the 'roughed up' surface of your new transom core as well as the inside mating surface of the hull structure. Have a cordless drill and some 1-1/2" flooring or other screws ready. Stick 'em together and then RIGHT AWAY drive some screws from the inside of the transom thru into your new core to 'clamp' in place while it cures. You do not want any air pockets in between the 2 surfaces!!! Air bubble = weakness and potential cracking.....cracking not good on transom. Remove screws once cured and fill holes with a mixture of resin and chopped fiber...that's fiberglass fiber, not All Bran

Now all you have to do is re-glass in your outer skin. To do this, you'll want to "step de-laminate" both the edges of the removed outer section as well as the existing adjacent outer surface. If you've done this correctly, you will have removed about 1/8" of fiberglass from all 'mating' edges so that you can then 'weld' everything back together by overlapping both sections with some thin strips of cloth and resin. Woven cloth is much stronger than splinter cloth.
Sand and prep joints and fill motor mount holes ( on outside surface only) with resin and chopped fiber, and you're ready to 'pinstripe'.
***IMPORTANT***: Back-drill motor mounting holes from INSIDE of transom thru new core and outer skin, they are original position.
Don't trust mounting hole location on outside skin as the position of outside skin may have shifted slightly after removal and re-installation.
Reinstall motor and you're good to go. Once you get those 4 motor mounting bolts
thru everything and tightened up, it will be as solid as new.

hope this helps.
good luck

[Cgranado]

Thanks that sounds like a pretty good idea. Also as i was crawling around i also noticed that the floor in the engine compartment is also really soft so i might need to gut it all from what if seen so far on other postings. Is it a huge thing to undertake?

[hookahawg]

never needed to do stringers, but if you can somehow remove the rot without cutting into your floor, you may be able to use this product
transomrepair.com (seacast)

used it on a transom once and it worked quite well.

good luck....

[Cgranado]

thanks alot for all the help and the info