Location of transducer airmar tm 260 on tomcat255

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joechiro30

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C Dory Year
2006
C Dory Model
255 Tomcat
I want to properly install an airmar tm 260 transducer on out Tomcat and I wanted to know where the best place to mount it.

Thanks

Joe
 
Generally you will want to put the transom mount transducer clear of any turbulence or prop wash. The bracket on the TC pretty well takes care of that. I put transducers on the outboard part of the Starboard hull and the port hull (two depth sounders). I have put two transducers next to each other. I prefer use of Starboard or similar material--on the transom, and then the transducer mount screwed to the Starboard. That way if you have to move or replace a transducer there are not further holes in the hull. (transom)
 
thataway":1tvftodz said:
Generally you will want to put the transom mount transducer clear of any turbulence or prop wash. The bracket on the TC pretty well takes care of that. I put transducers on the outboard part of the Starboard hull and the port hull (two depth sounders). I have put two transducers next to each other. I prefer use of Starboard or similar material--on the transom, and then the transducer mount screwed to the Starboard. That way if you have to move or replace a transducer there are not further holes in the hull. (transom)
Click to expand...

Do you have a photo of that? I don't know what you mean about the outboard part of the starboard hull. Right next to where the outboard is attached? Does it matter which side?
 
joechiro30":34hifv05 said:
thataway":34hifv05 said:
Generally you will want to put the transom mount transducer clear of any turbulence or prop wash. The bracket on the TC pretty well takes care of that. I put transducers on the outboard part of the Starboard hull and the port hull (two depth sounders). I have put two transducers next to each other. I prefer use of Starboard or similar material--on the transom, and then the transducer mount screwed to the Starboard. That way if you have to move or replace a transducer there are not further holes in the hull. (transom)
Click to expand...

Do you have a photo of that? I don't know what you mean about the outboard part of the starboard hull. Right next to where the outboard is attached? Does it matter which side?
Click to expand...

I don't have any pictures in the album and the boat is currently in the water but I did the same as Bob. Since the out board is attached to the hull, the location Bob refers to is not adjacent to the engine but rather in front of it. In brief, the cat hull has drain plugs in each side. Locate the plastic (AKA "StarBoard) mounting plates outside of the drain holes on either (or both) of the hull ends. Make the mounting plates large enough so that you can raise or lower the transducer as needed to get it running a little below the hull in the "clean" water flow. I think my mounting plates are about 3/4" x 5-6"w x maybe 8" tall. They are mounted into holes in the hull that were previously epoxy filled. The transducer is mounted to the plates. I also have one transducer on both sides of the hull (one on each sponson). I visually adjusted the transducer to run just a little below the bottom edge of the hull. I pick up bottom well up to about 20-25kts.
 
Thanks Bob and Roger for the help. Is there any way I can text you pictures of where we had it and where we are going to place it? Please PM you number if I can. I don't want to mess this up.

Joe
 
Not to speak for Thataway, but oftentimes on boats, the phrase "outboard of" (or inboard of) refers to the direction athwartships. So if say I have a galley counter and I want to refer to the part of it that is against the hull, I might say "the outboard edge of the galley counter." If I'm talking about the part that is near where I stand, I might say "the inboard edge of the galley counter."

So I think that's what was meant and nothing to do in this case with the outboard motor (meaning the Honda or Suzuki or etc. "outboard").
 
I have placed the transducer on the lowest part of the boat on the hull. Not on the bracket but on the lowest part of the boat forward from the engines. I don't seem to be getting accurate readings at the moment. We placed it on the starboard side
 
The aft transom, attached to the hull on the starboard side is correct. However, I off set the transducer to the outside of the hull, about 3" in from the chine.(outer edge) The bottom of the transducer needs to be parallel to the surface of the water, (pointing straight down, not following the contour of the hull.). You want the transducer about 1/8" below a straight edge along the bottom of the hull. I did not find a photo, in my album, and currently am not at home. Generally I hold bottom up to over 500 feet at 25 mph.
 
DSCN0138.sized.jpg
Here's where mine was mounted, on starboard hull. Shown during installation of bilge drain plugs. A worthwhile addition!
 
Dreamer":1lskennm said:
DSCN0138.sized.jpg
Here's where mine was mounted, on starboard hull. Shown during installation of bilge drain plugs. A worthwhile addition!
Click to expand...

Thanks Roger!! I bought the starboard you recommended 3/4". You install that first right? Use epoxy?
 
Does it matter where we mount the transducer on the hull? In other words is there an optimal place to put it. Do I place it on the most lowest part of the hull?
 
The reason I don't put the transducer at the lowest part of the hull, is that incase of grounding---for example stern to beach at Lake Powell, would be a potential semi intentional grounding--there would be more likely damage to the transducer, although in most cases it will flip up. If it does flip up, it is harder to put down, on the Tom Cat, because of the outboard bracket.

My feeling is that the water is a little less disturbed on the outer part (again I use the common term "outboard" of the drain plug.

I drilled two holes thru the Starboard for screws to attach it to the hull's transom.

I counter sunk the heads, so that you can mount the transducer screws at any place.

Put the block of Starboard, about 1/8" above the bottom of the hull and parallel to it. Drill two pilot holes into the transom, thru the Starboard block. Then over drill, these holes, fill with thickened epoxy, and then drill pilot holes for the screws to hold the Starboard in place. This way, there is no way for water intrusion into the transom.

There are very few materials which will stick to Starboard reliably. Various methods have been used to seal the Starboard to the transom: I cut groves into the starboard (best with a small dovetail bit in a Dremel tool, but cutting about 1/8" cuts with a saw are also adequate. You also want the back (hull) surface of the Starboard to be rough. (I use a rasp). Then apply either 5200, or G Flex epoxy to the hull side of the Starboard, and then secure the Starboard to the transom with SS or bronze Screws. I put a dab of the 5200 or G Flex onto the point of the screw (after it its thru the Starboard) before putting into the pilot hole,.

There are those who don't over drill and put epoxy plugs in, and those who don't grove the back of the Starboard. But the technique I outlined is least likely to allow any water intrusion into the transom. (The Transom of the Tom Cat 255 is foam--but you still don't want water in it.)
 
You have a very high quality, expensive, and heavy transducer and should exercise care when installing it. I don't know if the usual starboard mount will withstand the weight and forces generated on a transducer of this size and weight. As for location, the Tomcat owners are better qualified than the rest of us.

This link may help you with installation: https://www.youtube.com/watch?v=ZgUNGNb34ik
 
We are using a marine slow set 24 hr cure epoxy.

Can we use a quick epoxy set 50/50 instead?
 
Starboard mounts are more than capable of retaining this transducer--They are used for both this type, and a large downscan and side scan transducers on the same piece of starboard.

I wonder what makes one fell that Starboard would not work?

Joe, are you asking if just Kwick Set JB weld will work for the drilled out plug in the transom? If so, not alone, and I don't think it is the best material for the job, but it probably can be used, if you undercut the sides of the hole, as suggested, then paint the sides of all of this area, with some normal setting liquid epoxy, and then put in the JB weld before this has fully set up. My problem is that with the foam core, it may be difficult to get the entire hole and undercutting area filled 100% by stuffing in thick Kwick Set J B weld. I feel that there is significant risk of leaving a void and poor adherence to the underside of the glass and foam.

If you are asking if a standard slow cure epoxy would do for the underside of the Starboard (between the hull and starboard)--It is possible, but I would prefer 5200. If you had to use epoxy, then a standard cure would probably be better--
 
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