Adding transducer to transom on a 370 Dancer

[TheWolfTC]

Can anyone share what the best drill bit is to use when drilling through the transom of a 1996, 370 Sundancer? I need to drill a 1" hole through the transom for the transducer connection....How thick is the hull if anyone knows..
Also; type of bit
Spade?
Auger Type?
Hole saw?

I have drilled smaller holes before but not this large into the transom.
Thanks

 

[Bt Doctur]

depends on exactly where your drilling the hole.Most holes are WELL ABOVE the water line. The way to do a hole that goes thru the transom is:
drill the hole
place duct tape inside of boat
place duct tape outside of boat leaving a "pour area"
warm some resin first, add hardener and fill the hole and let cure
re-drill hole to size
What this tries to do is coat the exposed dry wood with a sealing agent to help prevent transom rot. This should be done to ALL holes that go thru any area that has a wood core.A alternate method is to install a hardwood dowel in the hole first coated in resin, drill to size and then recoat the hole.This leaves a dowel for sacrificing instead of the transom.

 

[TheWolfTC]

depends on exactly where your drilling the hole.Most holes are WELL ABOVE the water line. The way to do a hole that goes thru the transom is:
drill the hole
place duct tape inside of boat
place duct tape outside of boat leaving a "pour area"
warm some resin first, add hardener and fill the hole and let cure
re-drill hole to size
What this tries to do is coat the exposed dry wood with a sealing agent to help prevent transom rot. This should be done to ALL holes that go thru any area that has a wood core.A alternate method is to install a hardwood dowel in the hole first coated in resin, drill to size and then recoat the hole.This leaves a dowel for sacrificing instead of the transom.

Thanks...
Ok, so above the water line...no problem. I was going to drill it on the Stbd side above the trim tab piston where the swim platform actually has an upward notched area.
I get the filling with a resin as well but I am thinking that I would need to drill a "larger" hole than necessary by your description so as to drill it a 2nd time and still have the resin protect the transom core...is that correct?
Same with the wood dowel...get an 1-1/4" wood dowel for the actual 1" hole I need?

What type of bit do you generally drill a hole of that size with? I am thinking NOT a hole saw in case the transom is actually thicker in that area than the hole saw depth can handle?

 

[Redneck]

Have you thought of just epoxying your transducer on to the inside of the hull, say in the engine bay. All transducers will penitrate through fibreglass hulls with no issues. the only loss is water temp, that is, if your transducer has this option.
I have done this to many boats, best part, no drilling and no barnical growth on the transducer.

 

[TheWolfTC]

Have you thought of just epoxying your transducer on to the inside of the hull, say in the engine bay. All transducers will penitrate through fibreglass hulls with no issues. the only loss is water temp, that is, if your transducer has this option.
I have done this to many boats, best part, no drilling and no barnical growth on the transducer.

That was going to be my first option, as water temp wasn't a big issue for me since I am not really doing fishing that would rely on that these days. The only reason we want to know the water temp is so that we know how silly we are when we jump into Lake Michigan in June..LOL

All that being said, I was looking for the BEST place to put it that had a flat surface without a cavity below it and wasn't angled. The best flat surface is actually over the prop/prop shaft and I don't think that would be a good place to locate it...unless someone says it won't be an issue. All the other locations are angled to some degree and that won't work...I guess I could spend the bucks on a new transducer that is actually angled??? But for that money I might as well drill a hole...LOL
I am all ears for any other ideas about quality placement in the engine compartment....this would also save me from buying an extension cable for the extra 6 feet I need to get it to the helm.

 

[northern]

I installed one on my boat for the lower helm inside and it works well. I imbeded it in a bed oc cilicone and made sure it was flat to the water. I put about 1/2" of cilicone on clean dry fiberglass. Pushed the transducer into cilicone then covered the whole thing in cilicone used about a tube of it. It took about a week for that much cilicone to full set up. The transducer works better than the through hull one for the upper helm.