Hull thickness

[Colin Mac]

Hi from Australia. I'm a new member and have just bought a 2001 Maxum 4100 SCA and want to fit an in hull transducer, either an Airmar P79 or an M260. Can anyone tell me how thick the hull is just forward of the engines. Thanks in advance.

[jparsons121]

Hull thickness varies slightly based upon the location and the layup. Usually between 3/4-1+ in. Since you are looking at in-hull/shoot thru transducers, may I ask why the thickness is a consideration?

[Colin Mac]

Thanks for your respone, much appreciated. The P79 transducer is not recommended on thicknesses of more than 5/8" where as the M260 will be ok up to 1" thick.

[jparsons121]

Not sure where that info comes from, I’ve used the technical info in the link below as my guide for years. They state that there is no max thickness in fiberglass. They do share info of the combination of thickness vs frequency where there are certain combinations where you can have up to 10% degradation in the max depth (note degradation is not linear-thicker doesn’t mean more loss)
Once I saw the graphic that showed the max depth@50hz to vary from 3333ft with 0 glass and 2850 (worst case @1/2”) it really became a moot point for me as I’m not usually in waters any deeper than a few hundred feet.

I have the P79 in my 3000 and it works flawlessly.

https://vdocument.in/performance-of-...rformance.html

[Colin Mac]

Thanks jparsons121, appreciate the link.

[PJHoffnet]

Replaced my fathometer transducer a few months back - 1999 4100 SCA.

Hull is 3/4 of an inch thick at my 'ducer's location - about four inches outboard of the half bulkhead seperating the centerline area of the engine room and the port engine, and about two feet forward fo the engine.

[Colin Mac]

Thanks Paul much appreciate. Is the hull solid glass or is it cored?

[jparsons121]

All maxum’s are solid.

Edit: non cored with the exception of the transom which has marine plywood.

[Colin Mac]

Thanks for that.