98 Sundancer 270DA in hull sensor placement

[koresample]

Does anyone have any experience installing a Norcross (Hawkeye) 'in-hull' (epoxy to the inside of your hull) depth sensor? I have confirmed that I have a solid 'glass hull, no coring and I am having a heck of a time finding a spot where it will read. I have tried the vaseline to the base of the sensor tip but not the baggie of water one yet. I hang it over the side and it reads fine and one spot in the hull (just outside the starboard stringer, in front of the thru-hull pick up) read for about 5 seconds then all I get is " - - - " on the display. There is a spot directly on the keel in front of the motor that is perfectly smooth (just in front of the bilge pumps) and I have tried it there as well with no luck. I have searched the forum and there are a lot of posts on this but I can't locate one for my year/model but don't know if that is what is making this unique, or if I just need to try more things.

thanks!

 

[koresample]

bump

 

[Lazy Daze]

I think you might be getting suspended air in the vaseline.

The bag idea is interesting, never heard of that one before. My only concern would be whether or not the bag really sits flush against the hull surface, since it's bumpy/uneven. But, you'll know if you try. Sounds like it's worth a try, though.

Another way would be to build a "dam" out of rope caulking and fill it.

 

[worsty]

On that size boat you are better off going to a transom mounted transducer. First, it is simple to install and run the cable. Second, an in hull or shoot thru hull transducer loses 50% of its effective power from penetrating the hull. Yes, you might find a good flat area, but any air pockets, voids, or resin defects in the fiberglass will give you the dreaded "---". The Hawkeye depth gauge has an in hull or transom mount option, so exchanging it should not be a problem. You might even have the transom mount transducer and were just going to "glue" it to the inside of the hull.
The bag of water with the transducer inside is the best method for placement. When or if you go to glue it in place, use a good epoxy with no air voids in your application. If there are, then the same problem will arise with "---".
If going the transom mount direction, please use 3M 4200, NOT the 3M 5200 quick dry, to secure your cable holders. The 4200 will stay slightly flexable and is good for above the waterline, as long it is not in direct sunlight (under the swim platform is fine). Also, counter sink your mounting clip holes and transducer mounting holes (this will prevent the spider web cracking of the gel-coat, days-years from now). Good Luck.

 

[koresample]

it came with both mounting options but I want to put it in the hull as I don't have a simple way (i.e a trailer) to haul it out on to hang it from the transom. I have had it read once in the hull but then it blanked out. I am currently moored in the Fraser river which is pretty mucky at the best of time and has large tidal shifts (4-6 feet) but am moving to my new slip tomorrow. I will try the baggie next week once it is out of the murky water (it has read '- - -' even when hung off the side a couple of times, more than likely due to all the muck in the water) and see if there is any difference. Thanks for the feedback!

 

[Lazy Daze]

Yeah, soft bottoms can definitely screw up a reading. That's a good thought of trying it somewhere else. Good luck!