Sealing Holes In Hull Below The Waterline Which Were Used to Mount a SONAR Transducer

  ContinuousWave
  Whaler
  Moderated Discussion Areas
  ContinuousWave: Whaler Repairs/Mods
  Sealing Holes In Hull Below The Waterline Which Were Used to Mount a SONAR Transducer

search | FAQ | profile | register | author help

Author Topic:   Sealing Holes In Hull Below The Waterline Which Were Used to Mount a SONAR Transducer

fishtales posted 04-14-2009 05:41 PM ET (US)
I am changing my [SONAR] transducer and I want to install the new one on a piece of King StarBoard. How do I make sure I am not sealing water into the hull if I seal over the old screw holes? I removed the old transducer screws and it seems like there is moisture seeping out. Not soft or soggy at all. Or would it be best to move the block I am installing the transducer on to the side of the existing holes?
Thanks,
John
HAPPYJIM posted 04-14-2009 05:50 PM ET (US)
When I re-installed mine, all I did was squirt a little 5200 in the old holes and then had a beer. I wouldn't worry about any moisture in there.
20dauntless posted 04-14-2009 06:17 PM ET (US)
The best method is to drill out the hole until you find dry core and then fill with epoxy. You can use an allen wrench in a drill to remove excess core or use a dremel. Fill it with something like MarineTex (you can put a piece of tape over this so it will cure smoothly) then redrill into the epoxy. This way you won't have to worry about future water intrusion.
Mumbo Jumbo posted 04-14-2009 06:52 PM ET (US)
20Dauntless is correct in his approach. After drilling to remove all moisture-laden wood, seal with MarineTex. I have used stainless lag screws and 3M 4200 (fast cure) to secure the Starboard –or other flat stock– to the transom. If the lags are well sealed, one can move a transducer to different points on the pad without compromising the integrity of the transom. Just remember to use screws no longer than the thickness of the pad.
L H G posted 04-14-2009 07:02 PM ET (US)
The correct, and purist way to do it is to make it look like there never were any holes there to begin with.
Assuming these were drilled into the plywood core of the transom, first countersink bore the surface edges of the old holes, cleaning them up and providing a beveled, rough surface for bonding new gelcoat. Then pack Evercaot #27 polyester resin into the holes (Gelcoat does not bond well to epoxies like MarineTex or Wests), rough sanding flush. Then grind out a small relief for a top coat of gelcoat. Sand, buff, etc and you will never know the holes were there. It's really an easy process, and will look like this when done. This transom had 2 tranducers, and twin engines installed (the engine bolt holes were filled with wood pegs also)
http://smg.photobucket.com/albums/v429/lgoltz/Outrage%2019/?action=view& current=Scan0002.jpg
JOHN W MAYO posted 04-14-2009 07:04 PM ET (US)
I used Marine Tex also the repair the holes for the previous transducer mounting. Then used 3M 4200 to coat the screws and holes for the mounting of the new king starboard board. Be sure to use shorter screws that do not penetrate the king starboard into the transom mounting the new transducer to.
JOHN W MAYO posted 04-14-2009 07:13 PM ET (US)
LHR
Great repair job, boat looks great.
Which Whaler is that one?
It looks almost identical to my 1976 Revenge 19 except for the side had rails.
fishtales posted 04-14-2009 07:13 PM ET (US)

I went to the local plastic shop to buy a scrap of King Starboard and ended up with a similar plastic material 3/4" thick. But the guy who worked there said I would need to epoxy it to the hull with a resin epoxy because the 5,200 would not hold it without screws. Sounds a little too perminant for me. He also said the King Starboard would not stay with the 5,200 either. Any thoughts?
I am wondering now if i should just marine tex the existing holes and drill two new ones for the new transducer and bag the backing plate idea.
John
20dauntless posted 04-14-2009 07:25 PM ET (US)
Just screw the backing plate into the holes you just filled with MarineTex. This ensures that you won't have any water intrusion.
jimh posted 04-14-2009 07:35 PM ET (US)
[Moved to REPAIRS/MODS.]
L H G posted 04-14-2009 09:15 PM ET (US)
I agree, scrap the King Starboard idea. MarineTex works very well for resetting stripped out screws, such as rail bases, where the fittings will completely cover the non-matching white MarineTex and fit the same hole pattern. If you are going to use the same holes, drill out TWICE the original screw diameter and into the wood transom core, fill with MarineTex, sand and buff smooth. Then no gelcoat is needed.
John, the boat is a 1975 Outrage 19. The side rails are a custom design, using original Whaler components and hull fittings.
JOHN W MAYO posted 04-15-2009 12:00 AM ET (US)
LHG
Great looking rails.Great repairs. What motor are you going to install?
L H G posted 04-15-2009 12:31 AM ET (US)
http://smg.photobucket.com/albums/v429/lgoltz/Outrage%2019/?action=view& current=Scan0006.jpg
You can arrow forward and backward and see all photos I have posted so far.

Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.

Author	Topic: Sealing Holes In Hull Below The Waterline Which Were Used to Mount a SONAR Transducer
fishtales	posted 04-14-2009 05:41 PM ET (US) I am changing my [SONAR] transducer and I want to install the new one on a piece of King StarBoard. How do I make sure I am not sealing water into the hull if I seal over the old screw holes? I removed the old transducer screws and it seems like there is moisture seeping out. Not soft or soggy at all. Or would it be best to move the block I am installing the transducer on to the side of the existing holes? Thanks, John
HAPPYJIM	posted 04-14-2009 05:50 PM ET (US) When I re-installed mine, all I did was squirt a little 5200 in the old holes and then had a beer. I wouldn't worry about any moisture in there.
20dauntless	posted 04-14-2009 06:17 PM ET (US) The best method is to drill out the hole until you find dry core and then fill with epoxy. You can use an allen wrench in a drill to remove excess core or use a dremel. Fill it with something like MarineTex (you can put a piece of tape over this so it will cure smoothly) then redrill into the epoxy. This way you won't have to worry about future water intrusion.
Mumbo Jumbo	posted 04-14-2009 06:52 PM ET (US) 20Dauntless is correct in his approach. After drilling to remove all moisture-laden wood, seal with MarineTex. I have used stainless lag screws and 3M 4200 (fast cure) to secure the Starboard –or other flat stock– to the transom. If the lags are well sealed, one can move a transducer to different points on the pad without compromising the integrity of the transom. Just remember to use screws no longer than the thickness of the pad.
L H G	posted 04-14-2009 07:02 PM ET (US) The correct, and purist way to do it is to make it look like there never were any holes there to begin with. Assuming these were drilled into the plywood core of the transom, first countersink bore the surface edges of the old holes, cleaning them up and providing a beveled, rough surface for bonding new gelcoat. Then pack Evercaot #27 polyester resin into the holes (Gelcoat does not bond well to epoxies like MarineTex or Wests), rough sanding flush. Then grind out a small relief for a top coat of gelcoat. Sand, buff, etc and you will never know the holes were there. It's really an easy process, and will look like this when done. This transom had 2 tranducers, and twin engines installed (the engine bolt holes were filled with wood pegs also) http://smg.photobucket.com/albums/v429/lgoltz/Outrage%2019/?action=view& current=Scan0002.jpg
JOHN W MAYO	posted 04-14-2009 07:04 PM ET (US) I used Marine Tex also the repair the holes for the previous transducer mounting. Then used 3M 4200 to coat the screws and holes for the mounting of the new king starboard board. Be sure to use shorter screws that do not penetrate the king starboard into the transom mounting the new transducer to.
JOHN W MAYO	posted 04-14-2009 07:13 PM ET (US) LHR Great repair job, boat looks great. Which Whaler is that one? It looks almost identical to my 1976 Revenge 19 except for the side had rails.
fishtales	posted 04-14-2009 07:13 PM ET (US) I went to the local plastic shop to buy a scrap of King Starboard and ended up with a similar plastic material 3/4" thick. But the guy who worked there said I would need to epoxy it to the hull with a resin epoxy because the 5,200 would not hold it without screws. Sounds a little too perminant for me. He also said the King Starboard would not stay with the 5,200 either. Any thoughts? I am wondering now if i should just marine tex the existing holes and drill two new ones for the new transducer and bag the backing plate idea. John
20dauntless	posted 04-14-2009 07:25 PM ET (US) Just screw the backing plate into the holes you just filled with MarineTex. This ensures that you won't have any water intrusion.
jimh	posted 04-14-2009 07:35 PM ET (US) [Moved to REPAIRS/MODS.]
L H G	posted 04-14-2009 09:15 PM ET (US) I agree, scrap the King Starboard idea. MarineTex works very well for resetting stripped out screws, such as rail bases, where the fittings will completely cover the non-matching white MarineTex and fit the same hole pattern. If you are going to use the same holes, drill out TWICE the original screw diameter and into the wood transom core, fill with MarineTex, sand and buff smooth. Then no gelcoat is needed. John, the boat is a 1975 Outrage 19. The side rails are a custom design, using original Whaler components and hull fittings.
JOHN W MAYO	posted 04-15-2009 12:00 AM ET (US) LHG Great looking rails.Great repairs. What motor are you going to install?
L H G	posted 04-15-2009 12:31 AM ET (US) http://smg.photobucket.com/albums/v429/lgoltz/Outrage%2019/?action=view& current=Scan0006.jpg You can arrow forward and backward and see all photos I have posted so far.