Proper sealant for transom hole (transducer)?

[ricohman]

I am going to be drilling a hole in my transom and the top of my dash this weekend and I want to have the correct sealant before I start.
I have a tube of 4200. And I've heard the 5200 is very difficult to remove.
How about the 4000? This would be above the water line and for the screw holes on the dash.

 

[Cowthief]

Re: Proper sealant for transom hole (transducer)?

I am going to be drilling a hole in my transom and the top of my dash this weekend and I want to have the correct sealant before I start.
I have a tube of 4200. And I've heard the 5200 is very difficult to remove.
How about the 4000? This would be above the water line and for the screw holes on the dash.

I always fill OLD transducer holes with marine tex. I take a syringe and squeeze marine tex deep in the hole so its not just a 1/4 inch on the top. 5200 for new holes drilled in my opinion, you will be able to get the screws out. Above the water line and dash 4200.

 

[NSBCraig]

Re: Proper sealant for transom hole (transducer)?

use the 4200

 

[Georgesalmon]

Re: Proper sealant for transom hole (transducer)?

Use your 4200. It will be fine for this use.

 

[ozenine]

Re: Proper sealant for transom hole (transducer)?

I have used both 4200 and 5200 - similar result, both hold fine. The first time I have used 5200 to fill in 1 screw hole from the transducer I did not read the manual that said to wait for 48 hours for it to harden and wait 7 days for it to fully cure . long story short, I have never realized how much water can enter the boat through the tiny screw hole. My bilge pump was running almost all the time.
So when i got home I have resealed it and put a screw in there just in case. lesson learned. Need to add this to "Stupid Tricks forum".

 

[spoilsofwar]

Re: Proper sealant for transom hole (transducer)?

4200 and 5200 both come in fast cure variants... A few hours to tack and 24/48 hours to full cure, and they will cure underwater.

For your application, 4200 is the one to use.

 

[fishrdan]

Re: Proper sealant for transom hole (transducer)?

Richo, I'd 5200/4200 a piece of Starboard or HDPE (cutting board) to the transom, then screw the ducer to the plastic board. Use 2 screws to attach the board to the boat and seal the carp of it, then you don't have to worry about your ducer screws leaking. AND, when you want to replace that fish finder in 5 years, you don't have to worry about drilling different holes in your transom.

I used a chunk of Starboard on my 18'er, and a chunk of cutting board on my jon boat, both seem to work well. (Sanded the carp out of the back side of the plastic with 40 or 50 grit sand paper so the sealant had something to bit into)

If I had a tube of 4200, I wouldn't buy 5200 just to seal up some ducer mounting holes. I've used 5200 on ducers and haven't had problems removing them, but 5200 can and will remove paint if it gets a really good bond...

 

[ricohman]

Re: Proper sealant for transom hole (transducer)?

Thanks for the info.
I am going to use the 4200 and I have a Sternmate so I won't have any holes under water.
I will need to start a thread about the transducer location and my hull/trailer with bunks.

 

[ricohman]

Re: Proper sealant for transom hole (transducer)?

I have filled the hole for the cable with 4200 and filled the screw holes for the clamshell with 4200.
Do I need to run a bead around this fitting?

 

[Cowthief]

Re: Proper sealant for transom hole (transducer)?

Just make sure around the wire is sealed, it looks good. I always over do it though just to be sure, just my style lol.