I recently bought a Garmin 740S chartplotter…and purchased an inhull mount 200/50 KHZ transducer…
anyone have any experience with this?..I have a 1979 Freedom 40 it does not appear to work through the hull…
Garmin says it can’t handle more than 5/8" hull thickness…
does my boat have a balsam core?..how thick is it?
the unit has sonar capability and I would like to use it…right now it is not even showing the depth…
Capt. Herman …tampa
any help appreciated…
I have an 1996 F35, Pedrick design. I added a thru hull about 2 ft to one side of keel and when the core was removed it was a good 2 inches thick ( and dry!).
Gotta find out how thick your core is manually dont beleive any thing you read. Small hole through the inner skin then press by hand an awl slowly till you hit the inside of outer skin. Measure depth and then get proper hole saw to break inner skin to core, remove inner skin and pick out core. Major pucker factor if boat is in water. Insurance policy up to date? Numbknots
It’s almost certainly balsa core. Our’s is hull number 7 1976 and the hull thickness is over 2 inches thick. There is about 3/4 of an inch of fiberglass layup, then about an inch of end grain balsa, then about a 1/4 inch of inner hull. My recommendation would be to purchase a thru-hull with a long enough neck to be properly installed. Check with http://airmartechnology.com/ Keep in mind that the “normal” thru-hull transducer’s will not have a long enough threaded neck to accommodate a fairing block. Having said that, they do now make transducers that can be installed at an angle, and still shoot straight down. Again, airmar will be able to guide you to a proper product.
George