Mounting a transducer without drilling holes

mtorts

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Apr 14, 2011
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Hello all the fishing season has arrived and it's time to mount my new humminbird. I have read several threads where people are attaching starboard to the transom with 5200 then screwing the transducer to it so it eliminates drilling holes into the hull. My question is can I just use a white poly cutting board or does it have to be starboard. It seems to be much cheaper this way but I'm not sure how it would hold up agains years of UV from the sun??
 

ezmobee

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Re: Mounting a transducer without drilling holes

5200 won't stick to Starboard so that solution is right out.

I know some of the solutions I've seen have involved still mechanically fastening the board to the transom but the idea is that if you have multiple transducers or have to make adjustments, you still only have two holes in your hull.
 

Pez Vela

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Re: Mounting a transducer without drilling holes

You're missing the main point, which is whether the cutting board will adhere to the transom. UV degradation of either the cutting board or the adhesive would seem less of an issue. Maybe someone on here will mail you a scrap piece of starboard for free, or you could get real spendy and buy a SternSaver kit.
 

mtorts

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Re: Mounting a transducer without drilling holes

If 5200 won't stick to starboard is there anything else I could use?? Or could I use 5200 to attach the mounting bracket right to the transom. My boat is aluminum
 

ezmobee

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Re: Mounting a transducer without drilling holes

The only thing that technically sticks to Starboard is this crazy expensive 3M stuff called ScotchWeld. Not sure if the ScotchWeld then sticks to other stuff.
 

mtorts

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Re: Mounting a transducer without drilling holes

I will do some research on other materials other than starboard that 5200 will stick to
 

JASinIL2006

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Re: Mounting a transducer without drilling holes

Ricohman documented his install using a Sternmate, which allows you to mount the transducer without drilling holes in the transom. I tried to fashion a poor-man's Sternmate using a piece of poly cutting board that I adhered to the hull with 5200. I wasn't thrilled with the setup -- the 5200 took forever to set up, so I ended up modifying it a bit.

I used two thicknesses of poly cutting board. The first was attached to the hull with two screws thru the center of the board into the transom. The screwholes and the whole back of the poly board were coated with 5200. The second board was the same size as the first. I attached it right on top of the first, with four screws that only penetrated into the first board, and I slathered it with 5200 as well. This way, there was no direct route for the water to intrude. The poly board was large enough (about 4" x 4") that I had options to move the transducer around a bit to find the best spot. Since the transducer screws were only penetrating the poly board, I didn't have to worry if I needed to move the 'ducer and re-drill.

It seemed to work OK, although it wasn't the prettiest thing in the world (but hey, when it's on the water, who sees it?). I ended up pulling off a month and half later when I discovered my transom needed to be replaced. I was surprised to find that the 5200 in the center of the boards was not yet cured! It was still soft. It really made me question how well it would work as the only adhesion between the board and the hull.

Sorry to get long and rambly, but I thought this might be helpful.

Jim
 

mtorts

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Re: Mounting a transducer without drilling holes

I'm still wondering if just a cheap white cutting board at Walmart would work. They just say poly cutting boards. If anyone has the answer please let me know.
 

JASinIL2006

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Re: Mounting a transducer without drilling holes

That's what I used. I bought a larger one - and the thickest I could find - and cut it on a table saw.

Jim
 

mtorts

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Re: Mounting a transducer without drilling holes

Thanks for the info guys gives me another idea to consider. Thanks
 

Home Cookin'

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Re: Mounting a transducer without drilling holes

I have used cheap white cutting boards on my boats (as cutting boards) and found they degraded after several years of use. But your case, so what? You could even use marine plywood or better, cypress or other marine hardwood (not red oak!). If it lasts 15 years, great; if it lasts 7 years, replace it. No big deal.
 

mtorts

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Re: Mounting a transducer without drilling holes

When I googled 5200 wood is actually one of the materials that it bonds really good with so that might not be a bad idea. It mentioned fibreglass but nothing about aluminum which makes me a little nervous. I think I might try the wood idea and zip tie the transducer cord to something solid incase it falls off. Maybe to the other transducer which is screwed into the transom. They will most likely be side by side.
 

fishrdan

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Re: Mounting a transducer without drilling holes

I wouldn't just glue the board to the transom, though I know a few have said it worked from them. I'd atleast hold it on with 2 screws, then screw the ducer in to the board. I have a "Starboard" ducer plate on my 18'er and a cutting board ducer plater on my 14' jon, both work well, though they are not stored in direct sun light. With both of them I scratched the 'ell out of the back side of the plate with 50 grit sand paper, to give the 5200 something to bit into, seems to have worked well.

I ended up pulling off a month and half later when I discovered my transom needed to be replaced. I was surprised to find that the 5200 in the center of the boards was not yet cured! It was still soft. It really made me question how well it would work as the only adhesion between the board and the hull.

5200 is moisture cure, so I always mist the area being bonded with a very light coating of water, if it's a wide area. This would have solved the uncured 5200 problem.
 

Don S

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Re: Mounting a transducer without drilling holes

5200 isn't water cured, it's air cured.. Spraying water will only surface cure it, but it's still going to take a week to fully cure,
 

64osby

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Re: Mounting a transducer without drilling holes

It's hard to tell from the picture but there is a 3" wide alum plate that is mounted above the water line to the left of the ladder. A piece of wood is mounted to it down low. The transducers are mounted to the wood.

http://forums.iboats.com/attachment.php?attachmentid=112533&d=1315444588



On my small tinny I used a piece of alum using an existing hole at the top to mount the transducer.http://i1158.photobucket.com/albums...erman 1963/LSTransducerMount.jpg?t=1342311914


So no holes below the water line.
 

reelmess

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Re: Mounting a transducer without drilling holes

If you use wood, I'd look for something that don't rot, black locust comes to mind off hand.
On my one aluminum boat, it came with a factory plastic block bolted to the transom with all three transducers attached to it. The plastic block attaches with two screws threaded into threaded, blind hole rivets. (Nutserts).
 

mtorts

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Re: Mounting a transducer without drilling holes

So many ideas still no idea which method to use lol. There is a fast cure 5200 which only takes 24hrs to dry so that might be useful for which ever method I use. Thanks a lot guys great info out there. I will post a pic hopefully next week when it is all set and done.
 

Texasmark

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Re: Mounting a transducer without drilling holes

Mount it inside with epoxy. Then you won't have to worry about the mounting, or getting damaged in normal boating nor trailering.

Mark
 

Yacht Dr.

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Re: Mounting a transducer without drilling holes

So many ideas still no idea which method to use lol. There is a fast cure 5200 which only takes 24hrs to dry so that might be useful for which ever method I use. Thanks a lot guys great info out there. I will post a pic hopefully next week when it is all set and done.

I have done what your wanting to do before. You dont want to put holes in your transom for a transducer. Ok no problem.

Find a chunk of fiberglass 1/2" thick. ( or make one yourself ).
Template the fiberglass to your ducer mounting plate.
Mark were the Mount will be on your transom.
Grind the gelcoat off the transom were the mount will be.
Epoxy the Fiberglass mount plate to the transom.
Sand and 5200 fast cure + screws your ducer bracket to the mount plate.

One thing to keep in mind about Bonding .. your only Bonding to the surface. So lets say you found a way to 5200 some wood or cutting board solid enough to hold. .. your gelcoat is the bonding profile. In Any way you decide to do this you should still remove the gelcoat to raw glass.

Hope this helps :)

YD.
 
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mtorts

Seaman
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Apr 14, 2011
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Re: Mounting a transducer without drilling holes

My boat is aluminum not fibreglass so would finding a 1/2" piece of aluminum be better?? Will 5200 work on aluminum. When I researched it, it mentioned fibreglass wood plastic a few others but not aluminum?? I'm sure it would be fine sounds like quite a few people on here used it before.
 
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