patching transducer holes in transom

[Mistermojo]

I just picked up a humminbird 587 and will be removing an older lowrance. There is currently the transducer itself and the speed sensor attached directly to the transom via screws or bolts. I am going to remove both of these and will need to patch the holes. What is going to be the best way to patch and make sure they are good and sealed for the long term?

Also, should I invest in one of those transducer mounting plates for the new transducer?

Thanks,

Mojo

[20lbSloughShark]

I'm not sure how yours is mounted, but the best thing to do, is use one of the existing (or both if you can) to mount the new one. Any extra hole just put the screw back in. If you can't put the screw back in (transducer in the way) simply calking or JB weld works for me.

[Jim Almquist]

I put a stainless nut,bolt and lock washer in with a good shot of silicon. I then mounted one of those plates on so I would not put any more holes in my boat. Works great!!

[Gus]

I didn't have access to the back of the hull in that area, so I just used a good shot of silicone and a pop rivet. Re siliconed the outside and then mounted a transducer board over the holes. Slightly bored some indents for the rivets to sit in so the board mounted perfectly flush. Silicone under the board and around it. Maybe overkill, but it seems to work.

[BartmanMN]

This is what I did.

1. Removed old transducer and speed sensor

2. Scraped off old gunk from transom.

3. Filled the holes with 3M 5200 and put some 5200 on the threads of the existing stainless screws, then I screwed them back in. Figured this would seal the holes the best.

4. Purchased mounting plate

5. Counter sunk the mounting plate so it would mount flat on transom over the existing screws (if mounting in same location).

6. Drilled holes for mounting plate, filled holes with 3M 5200, and put some on threads of screws. Placed bead of 3M 5200 around the entire mounting plate and then installed plate to transom.

7. Let dry for a couple days.

8. Mount new transducer to mounting plate.

I think the mounting plate is worth it. I much prefer drilling into that rather than my transom, especially if you need to fiddle with the mounting location of the ducer after the fact.

[Mistermojo]

Thanks guys for the info - will pick up a transducer plate and some sealant for sure. Now - anyone have a lakemaster or navionics chip they want to sell cheap?

[amateurfishing]

I'm not sure how yours is mounted, but the best thing to do, is use one of the existing (or both if you can) to mount the new one. Any extra hole just put the screw back in. If you can't put the screw back in (transducer in the way) simply calking or JB weld works for me.

+1 on using existing hardware/bracket mounts if possible, why go thru the rest of the mess if it is unncessary? may have been dumb but jb weld my new puck to hull, no holes needed

[fishnowworknever]

BartmanMN is spot on. Get some 3M 4200 or 5200 like he mentioned. Make sure you don't use regular silicone - Life caulk works great below the waterline as well.

[Comit 2]

+2 with the JB weld (epoxy) and screws.

[SpecialK]

I had to cut my screws off so I just used the JB Weld Stick. No leaks at all.