Shoot through hull problem

[Member]

Hi all.

I took my Garmin 178C out of my boat and stuck it in my kayak. On the boat it was transom mount Trans...worked well. In the yak i glued trans to inside of plastic hull in a nice flat position at about the middle of the yak. Made a barrier of foam. Later filled the pool with sellys All clear silicon and carefully pushed it down to the bottom. Sanded hull and trans first. Heated silicon first to avoid big bubbles but there will be tiny ones. Now in the water i see a line at the top of the screen...is this to be expected with shoot through hull applications?

So first 20% of the screen is white line.  It's certainly picking up fish and structure below that however. No amount of changing gain or range gets rid of the top line.

Cheers

Sorry guys I think I deleted all posts on this topic which I didn't think was possible...technology🙈

So pulled Sellys 3 in 1  out...it set like cr@p.   Photos tell story and now in with smooth, silky Sikaflex




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[Member]

Original topic restored & merged with new topic 

[Member]

bubbles explain the white bar in the screen lol

[Member]

I had this happen to me before. Even after doing all the recommended things to reduce bubbles, my all clear was full of them. Now, I only use the wet mount method - same piece of foam with the cutout glued to hull, but now I just add a little water to the cutout each trip and press the tranny into that. A bit of water squirts out but I just clean that up with my sponge. No bubbles, great image and easily removable if I want to transfer to another yak later. I don't know why people still go with the glue down method.

[Member]

Thanks mate.  In my case I dont need to taken the trans out of the boat so for me, and given that I carry it upside down, it works well to have it glued down and just forget about it.  It makes for quicker entry and retrieval/loading.  It is a very powerful unit in terms of RMS so it will blast through 0.5-1mm of Sika and a 3mm hull without any dramas.

Cheers

[Member]

OK, had it out at Kurwongbah on the weekend.  Great clarity from this older unit.  Only a very thin white line at the top representing the plastic and thereafter clear as a bell, with nice arches both small and large.  The trans must be nice and level to the return signal because the arches are beautifully shapped, especially on the larger fish. I could also see my line being worked under the yak.

Donut however...they were not ont he chew for me - tried vibes, plastics, divers, spinners etc.

Cheers