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General Category => General Discussion => Topic started by: landroverphile on April 24, 2015, 05:51:10 PM

Title: Shoot through hull problem
Post by: landroverphile on April 24, 2015, 05:51:10 PM
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


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Title: Re: Shoot through hull problem
Post by: aussiebasser on April 24, 2015, 06:47:58 PM
What is your kayak made out of?
Title: Shoot through hull problem
Post by: landroverphile on April 24, 2015, 11:21:36 PM
Plastic mate.  Nice clear spot away from scuppers and not on a chine.  No air under boat at that point. 

Cheers


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Title: Re: Shoot through hull problem
Post by: aussiebasser on April 25, 2015, 12:53:54 PM
Some plastic Yaks have a double skin, foam filled, that will cause problems.
Title: Re: Shoot through hull problem
Post by: cfish on April 26, 2015, 05:45:15 PM
I'm shooting though the bottom of my polycraft boat at least ten mill thick and getting a satisfactory result after moving it a few to different positions,I'd try a regluing it should be better than you getting now.
Charles
Title: Re: Shoot through hull problem
Post by: Sweetwater on April 26, 2015, 08:45:20 PM
I've fitted dozens of Humminbirds into kayaks with no issues, never fitted a Garmin so I can't offer any assistance.
Title: Re: Shoot through hull problem
Post by: hanna2nv on April 27, 2015, 03:21:10 PM
You shouldn't have sanded the hull as that could affect it and also the smallest air bubble can make the signal screwed up  the way to avoid bubbles is to kee theglue nozzle small aand leave the tip in the glue as you pour it   and yea alsondepends on the kind of hull if solid plastic or foam layered
Title: Shoot through hull problem
Post by: landroverphile on April 27, 2015, 04:24:00 PM
Hi all, thanks for the replies. No foam. Plenty of bubbles I suspect despite heating the goo well beforehand, sanding shouldn't effect....? very fine sandpaper...

I might remove and use a thin amount of Sikaflex this time...going to be a pain to remove if it ever has to come out again. I will make sure I bottom the transducer out fully too.

Cheers


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Title: Re: Shoot through hull problem
Post by: hanna2nv on April 27, 2015, 05:53:55 PM
Fine sandpaper is alright keep with the sellys all clear I used 3 in 1  just no bubbles
Title: Shoot through hull problem
Post by: landroverphile on April 27, 2015, 07:41:05 PM
So mate 3 in 1 is like Sikaflex?

Cheers


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Title: Re: Shoot through hull problem
Post by: hanna2nv on April 27, 2015, 10:36:50 PM
i only used sellys 3 in 1 cause i also glued the sounder base down instead of screws   the all clear should be perfect as everyone uses it and its fine. just avoid air bubbles and try get the face of the transducer right down onto the hull
Title: Re: Shoot through hull problem
Post by: hanna2nv on April 27, 2015, 10:39:26 PM
seeing as you have a mould for the transducer fill it half way with silicone then push the transducer to the bottom then top up the hole a little
Title: Re: Shoot through hull problem
Post by: Sweetwater on April 27, 2015, 11:26:30 PM
I've used all clear in the past but reckon they've changed the formula, takes forever to go off, don't like it as much now. Just make sure you use a neutral cure sealant. An acid cure can react with the transducer. Acid cure sealants smell like vinegar.....

AquaSeal, Fixtech & Sikaflex are good brands. Sorry, only registered users can see this content. Please Login or Register.
Title: Shoot through hull problem
Post by: landroverphile on April 28, 2015, 07:05:24 PM
Took it all off mould also...its was all glued together.  Took about 45 mins with screw drivers and a small crow bar I kid you not.  It was never going to drop off by itself!  it had bubbled...hundreds and also was not properly bedded in one corner, so I must have not pushed it down evenly and the pool surround obscured the fact.  So this time pumped Sikaflex, and a LOT less, onto the face of the trans, all over the face, and just pressed it down evenly straight onto the hull floor without a surround. Rock on top. Now a few days in the sun hatches open and I should be in business. I do like Sika.

Cheers


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Title: Shoot through hull problem
Post by: landroverphile on April 28, 2015, 09:03:17 PM
Photos tell the old and new story....




Title: Shoot through hull problems
Post by: landroverphile on April 28, 2015, 09:13:01 PM
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

(http://images.tapatalk-cdn.com/15/04/28/5b437d0c63fa0bb9995eea76a4974c23.jpg)(http://images.tapatalk-cdn.com/15/04/28/e454543d4820171a69edba34ff44a536.jpg)(http://images.tapatalk-cdn.com/15/04/28/3faadcfffaeccae7244f17a320b9c94f.jpg)


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Title: Re: Shoot through hull problem
Post by: admin on April 28, 2015, 10:29:38 PM
Original topic restored & merged with new topic  :tick
Title: Re: Shoot through hull problem
Post by: hanna2nv on April 28, 2015, 10:33:14 PM
bubbles explain the white bar in the screen lol
Title: Shoot through hull problem
Post by: beetleyak on April 29, 2015, 07:14:49 AM
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.
Title: Re: Shoot through hull problem
Post by: landroverphile on April 30, 2015, 12:52:49 PM
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
Title: Re: Shoot through hull problem
Post by: landroverphile on May 04, 2015, 02:18:17 PM
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