Filling Large transom hole - options

[stevebrownell]

Any suggestions as to how to fill a large circular hole in the transom? My boat has an exisiting cutout about 4" round, half of which is below the waterline. Currently, there is a standard screw in deck plate holding back the sea....

Was thinking epoxy w. high strength filler, double up on a beveled piece of marine ply, wetted out, glassed, etc. It'll look like crap, but anything is better than the plastic that is there now. I do not plan on doing a transom replacement at this time, just want to plug the existing hole.

[JW-Tex]

If you have inside access to the hole you could remove the deck plate clean up the area wet out the edge with epoxy put the deck plate back in and fill the whole with epoxy and plywood from the inside. The outside will look the same (all you will see is the deck plate) and no gaping hole in the event the deck plate fails.

[FELLOW-SHIP]

I would do it the right way. Just like all holes to be fill in, the size is not a issue unless it effects the strength of the transom. I would first enlarge the hole on a taper of 30 degrees towards the outside of the boat meaning that your 4” hole will open up to a approx 8” hole on the outside skin of your transom maybe even bigger. Then I would cut a round approx 8” by ¼” thick piece of fiberglass sheeting and epoxy it in the inside of the hole where it still is approx 4” diameter let epoxy get hard then if you have room I would place one or two layers 16”x16” again in the inside over the 8” fiberglass disk for additional strength. Then I would start building the transom back by using ½” thick plywood then two or three layers of glass then another ½” plywood and then more glass cutting the plywood again on a angle to best represent the angle of the bigger part of the hole using filler around the edges of the plywood to help fill in the gap. I would use approx ½ fiberglass and approx ½ plywood for filling in the hole then faring material, sanding, and lots of beer. Then gel coat or paint
FellowShip [img]/images/graemlins/smirk.gif[/img]

[stevebrownell]

Looks like a project...thanks for the replies. Will most likely end up beveling and building it up, glass and plywood.
going to look like crap from the outside, but it beats a hull breach or failure of the deck plate.

I promise to start sending pics of before and after as soon as possible.

[FELLOW-SHIP]

Steve
I had 153 holes in my transom when I re did my boat and none of them are visible and none look like crap. Your gel coat or paint job (maybe the entire transom) will fix that.
FellowShip [img]/images/graemlins/wink.gif[/img]

[Capt Chuck]

Ken

I had 153 holes in my transom

What did you do before refurbishing that boat, take up squirrel guns [img]/images/graemlins/grin.gif[/img]

[stevebrownell]

Thanks Fellow-Ship, I'm going to charge ahead this weekend. 153 holes....whew.

[FELLOW-SHIP]

Ya 153 holes at least I didn’t have to think much about needing to do a transom job kind a like a no brainer.
Let’s see 8 large holes for twins, 16 large holes for a aluminum transom support type for the transom, 21 holes for 3 transducers most plugged up with 5200, 20 holes for trim tabs, 7 large holes for drainage holes through the transom, 12 small holes for screws on those drain holes, 12 holes for a transom ladder, 4 large holes for the eye cleats on the transom, 5 smaller holes for a 90 degree step on the transom, there were about 8 larger holes that were plugged up with wood and some epoxy, and the rest I am not sure why Oh Yeah I did drill a few myself just to confirm that the water that came out was not good enough to drink. I used most of the holes any way on the glue and screw method of tying the plywood to the transom. I did use 2 layers of glass on the inside first in the rebuilding process of the transom and then filled in all the holes faired it out and painted.
FellowShip [img]/images/graemlins/tongue.gif[/img]

[Capt Chuck]

Oh Yeah I did drill a few myself just to confirm that the water that came out was not good enough to drink