Screw hole repairs in transom

Hi fellas, looking a bit of info and guidance as to what is the best way to repair screw holes in the transom of my boat? Also does anyone know where I could get a thick piece of plastic or something that I can sikaflex over the top so I don't need to put any more holes in my boat for transducer adjustments? Cheers in advance 

Swompa's picture

Posts: 2456

Date Joined: 14/10/12

I have just filled a heap in

Mon, 2018-10-29 07:19

I have just filled a heap in the back of my boat. Drilled it out slightly with the next size bit, then drilled around 5-9mm into the face with a 10mm bit then filled up the hole into the hull with sikaflex then topped it off with bog. Sand and re-apply flow coat.

I am doing a major job on my boat so there may be better ways but that's what I am doing

pelagicyachts's picture

Posts: 879

Date Joined: 23/02/11

sika will end up leaking -

Mon, 2018-10-29 08:16

sika will end up leaking - ideally you should use epoxy resin-

Swompa's picture

Posts: 2456

Date Joined: 14/10/12

Hence filling the 10mm hole

Mon, 2018-10-29 12:01

Hence filling the 10mm hole with bog prior to flow coat.

quest's picture

Posts: 240

Date Joined: 03/08/15

 To flood weld the hole, sand

Mon, 2018-10-29 10:02

 To flood weld the hole, sand and paint would be best.


What you can do is drill, tap and fit a grub screw with sealer. If your transom is at least 5mm it shouldn’t be problem to tap thread into it. 

Posts: 359

Date Joined: 19/06/14


Mon, 2018-10-29 12:09

Drill out the hole with a countersink bit , fill with epoxy thickened with micro balloons. Let dry sand back , skim coat with more epoxy if needed . Prime and sand then add two coats of topcoat colour. Swompa do yourself a favour and drill out the sika and start again !!! . It will bite you in the bum sooner or later 


 My wife understands why I clean my rods n reels in the shower....


IncognitOh's picture

Posts: 103

Date Joined: 29/04/17

Cutting boards

Mon, 2018-10-29 13:16

Jadeo, am pretty sure I have seen those thick white plastic kitchen cutting boards on trailer boats used for transducer mounts.

I couldn't comment on their suitability but am sure others could. 

Posts: 243

Date Joined: 08/06/15

Cheers lads

Mon, 2018-10-29 13:37

 Went to my local Chandleryshop in the Mandurah mariner and got a product called Epifill. Got a good size off cut of thick plastic from Cut Out Plastics. Got home and took out the screws from the previous owner and f$&@ me a little bit of water came of the bottom ones. Thankfully it would not have been anymore than than about 30mls. Glad I decided to it bit the bullet and do it properly. Some people just have no bloody clue at all.