# Inboard Transducer Mount - Silicon or Sikaflex?



## Bart70 (Jan 28, 2007)

Hi,

I want to mount my transducer 'inboard' on the Outback. My yak dealer tells me that he has done this several times using 'Selleys All-Clear' silicone with success - he claims it 'etches' the polyethylene better and holds better than other silicones....Having used All Clear myself for other uses it does seem more 'gluey' (bit like a cross between epoxy & silicone) than normal silicon.

Has anybody used 'All Clear' before?.....What are everyones thoughts on this as opposed to Sikaflex?.....

All opinions gratefully accepted....

Bart70


----------



## Dan A (Aug 29, 2005)

Bart70 said:


> Hi,
> 
> I want to mount my transducer 'inboard' on the Outback. My yak dealer tells me that he has done this several times using 'Selleys All-Clear' silicone with success - he claims it 'etches' the polyethylene better and holds better than other silicones....Having used All Clear myself for other uses it does seem more 'gluey' (bit like a cross between epoxy & silicone) than normal silicon.
> 
> ...


Sikaflex tends to shrink a bit when it drys out and can cause the transducer not to have a good stick and can fall off a bit easier.

I have used silicon, although not all clear and it has stuck very well, hasnt fallen off yet.

Be careful with some silicons though as some actually eat away at the plastic to make a bond, forget which brand now.

Dan


----------



## Peril (Sep 5, 2005)

I've had sikaflex fail twice now with my current yak, despite taking all the recommended precautions. Might have to give All clear a go


----------



## JD (Jul 2, 2006)

Bostic clear from Bunnings


----------



## mal.com (Feb 10, 2007)

HI I used sikaflex & had problems, ie no reading  . Then I used all clear and it works beautifully.

I squirted the silacon into an aluminium egg, ring then plopped in the transducer & taped the whole lot to the base of the yak, this stops the silacon going walkies. I cleaned the area down with metho first, followed by a very fine sand down.

cheers

mal ....................oh yes the egg ring is still there


----------



## andybear (Jan 15, 2006)

Amazingly, you can just pop your transducer in a zip lock sandwich bag, with some water in it. and thats it. 
If you decide to sikaflex your transducer in, just remember to take a zip lock bag with you in case it stops working. It will get you through the fishing session until you can re fix it!

Cheers all Andybear :lol:


----------



## Dodge (Oct 12, 2005)

Someone on the forum had a warranty repair done at Viking recently, and when the subject of sticking tranducers came up the Viking man said use All Clear


----------



## fisher (Aug 30, 2005)

For one reason or another I've had to reglue the transducer to the hull now a total of 4 times. I've used both sikaflex and the selleys product (construction adhesive or similar?) and found the selleys product to be much more 'sticky'. Whilst sikaflex comes away from the hull AND transducer in one smooth blob, the selleys stuff has to be cut off the transducer with a sharp knife or razor. If I have to go the 5th time (apart from slashing the wrists), I'll go the selleys.


----------



## JT (May 25, 2006)

You know when I saw this thread I thought people will be saying Sikaflex all the way.

I am on my 3rd incarnation of Sikaflex and the third attempt has failed despite the fact that it was the best installation I have done....or perhaps not 'cause it doesn't damn well work :evil:

Andybear...how do you stop the transducer moving around in that plastic bag of yours and how do you seat the bag in the hull?

I am that pissed off with the amount of faffing around I have done that the bag or the Selleys seems like the next attempt, despite the fact that the Sikaflex did work well for a while (until it unseated itself again).

JT


----------



## HiRAEdd (Nov 12, 2005)

Sikaflex is far to messy and difficult for my liking.

I used marine grade silicon the first time around and it didn't hold long term.

Now I've used Selleys All-Clear and used a pool noodle to further enhance the pressure on the transducer and I've got the best signal ever.


----------



## Red Herring (Dec 18, 2006)

I'd have to say All-clear as you can 'work' out the bubbles with your finger before you apply the transducer. From my experience All-clear achieves the better bond.

Cheers,
RH


----------



## tugboat (Nov 15, 2006)

Most kayaks are made of Polyethylene or Polypropylene so there isn't many products that glue/bond to this.

Found the following article:
http://forum.kayak4fish.com/viewtopic.p ... add9b46608
"Sealing and Bonding Polypropylene and Polyethylene

by Jeff Lucius 
Introduction 
This short note briefly presents a relatively new product (around the year 2000) for bonding polypropylene and polyethylene, 3M's Scotch-WeldTM Structural Plastic Adhesive DP-8005. But first, a little background on plastics, and in particular, polyolefin plastics.

Polymers are natural or man-made chains of structural units called "mers", which consist of basic chemical elements such as carbon, hydrogen, oxygen, nitrogen, and silicon. Natural polymers include tortoise shells, animal horns, tar, and amber. Man-made polymers include plastic. The first commercial plastic was Celluloid, made in the 1860's. In the early 1900's, Bakelite (or Phenol formaldehyde plastic), rayon, vinyl, and nylon were introduced. The 1940's and 1950's saw the development of polyethylene and polypropylene plastics, generically called polyolefins. Polyolefins are made from the petroleum-based monomers of ethylene and propylene, and are the most common commodity plastics in the world. Polypropylene (PP) is Code 5 in the Society of Plastic Industry's (SPI) resin identification code. High Density Polyethylene (HDPE) is SPI Code 2 and Low Density Polyethylene (LDPE) is SPI Code 4. These codes usually appear inside a triangle stamped or molded into the plastic product. More information about the SPI codes can be found at SPI's web site, http://www.plasticsindustry.org/.

Polypropylene and polyethylene are called "low energy" or "non-stick" plastics. This group includes Teflon (or polytetrafluoroethylene). The basically inert or inactive molecular structure of PP and PE is described as a "low energy state". This "low energy" quality and relatively inexpensive manufacturing costs make PP and PE an ideal plastic for milk jugs, liquid detergent bottles, grocery bags, many food product bottles, toys, medical tubing, appliance parts, and many auto parts. On the Dodge Stealth and Mitsubishi 3000GT, polypropylene and polyethylene are used to make the splash shields inside the fenders and various exterior trims and mouldings (see 2-synth-parts.htm).

Despite their widespread usefulness, "low energy" plastics have a quality that can make them hard to work with - they are difficult to seal or bond using commonly available sealant adhesives. Cyanoacrylate, epoxy, polyurethane, silicone (RTV for example), and most acrylic adhesives do not stick to polypropylene and polyethylene. I have personally verified this with cyanoacrylate ("Superglue"), two-part epoxy, and several types of silicone RTV adhesives. In the past, PP and PE had to be surface treated to convert their low-energy polymer into a higher-energy state in order to improve bonding. Recently, 3M developed a unique adhesive that allows structural bonding of PP and PE to similar plastics, without any surface treatment except cleaning and light sanding, and to other surfaces such as other types of plastics, wood, aluminum, glass, and concrete. This product is absolutely amazing!

DP-8005 
Scotch-WeldTM DP-8005 is a solvent-free, two-part, acrylic-based, structural plastic adhesive designed to structurally bond polyolefins to themselves and to many other substrates. It uses a one-step process that requires no pre-treatment of the substrates other than removing dirt and oil. Like Polyolefins themselves, DP-8005 provides very good chemical resistance. Similar to most polypropylenes and polyethylenes, maximum continuous service temperature for DP-8005 should be kept under about 212Ã‚ÂºF (100Ã‚ÂºC).

Using the special 3M applicator, ten parts of the methyl acrylate base are mixed with one part of the amine accelerator. At room temperature, you have 2 to 3 minutes to work with the adhesive. You should note that this adhesive has a very-limited shelf life, only 6 months from the date of shipment when stored at near-freezing temperatures in the unopened original container (Note: I have used this product successfully about 6 months past the "expiration" date). Complete instructions and property information are available in the 3M product data sheet misc/dp8005.pdf.

Previously only available in bulk quantities for industrial use, DP-8005 is now available for retail sale in small 35 ml (1.18 fl. oz.) cartridges. You may have a difficult time finding DP-8005 in the local hardware store. I purchased the adhesive and applicator system from a 3M distributor in Denver, Colorado. They have walk-in retail sales for purchases over $50, and take phone orders for shipment anywhere in the USA. They accept Visa and Mastercard. Their contact information is below. 
Lane Supply Company 
2050 West Barberry Place 
Denver, CO 80204 
Telephone: 303-534-5371 
Fax: 303-825-1514 
The adhesive itself is not too expensive but the applicator system is. Fortunately, the applicator is completely re-usable, except for the nozzle. You will probably want to pick up one or two extra nozzles. The nozzle has a dual spiral design inside to promote mixing of the two components. The applicator system can also be used with other 3M Scotch-Weld Structural adhesives that come in 35-ml cartridges. Below are the prices charged by Lane Supply Co (in 2002). 
Description Unit Price 
DP 8005 35ml Scotch-Weld Epoxy $16.33 
EPX Plus Applicator $45.81 
EPX 10:1 Plunger $5.40 
EPX Mixing Nozzle 9164 for DP-8005 $2.68

On-line References 
About Plastics: 
http://www.americanplasticscouncil.org/ 
Introduction to Plastics: 
http://www.handsonplastics.com/hands_on ... chers.html 
Plastics Reference Handbook - Engineered Plastics: 
misc/engineered-plastics.pdf 
Plastics Reference Handbook - Technical Data: 
misc/plastics-techdata.pdf 
Polymers: 
http://www.lsa.dmu.ac.uk/Research/LSA/c ... _text.html 
SPI Resin ID codes: 
http://www.americanplasticscouncil.org/ ... codes.html
_________________
"

Been thinking this might be the solution... however it seems costly.
Have had a look at the 3M site to find more info:
http://multimedia.mmm.com/mws/mediawebs ... 8oCOrrrrQ-


----------



## grimo82 (Jan 16, 2007)

Does the same go for sealing deck fittings??

Dam, i just bought a $22 tube of marine grade sikalflex!!


----------



## DougOut (Dec 31, 2006)

Bart70 said:


> Hi,I want to mount my transducer 'inboard' on the Outback.


Mate, don't mount it inboard at all.
outboard is the way to go
& outboard in a fashion that you can unclip it and *point it at structure/s*
imagine your shinning a torch around at night 
but now it's your transducer *in your hand*
point it at bridge pylons etc. you'll be amassed at finding fish all around you instead of just straight down
IMHO everyone should be doing this
on second thought NO, all the more fish for me :lol:


----------



## andybear (Jan 15, 2006)

Hi JT

I have used this method without using anything at all to secure the bag to the hull..... just the bag, and if the hull has a "U"profile, the bag meets the shape.

Last time out, I moved the bag to another part of the hull....just a flat spot, and this time used a section of rectangular PVC, just to give the bag some shape, and that worked too. Please see "Transducer wet mount version 2" I think I submitted that a couple of months ago.

I will admit, the definition is not as good as I was getting when I had the transducer mounted outboard in the water, but generally it works quite well if the water is more than 1.5m deep. (In other words, if the display looks like intermittent crit, it means there is not a lot of water under the yak!

In principle I like the transducer locked to the yak as tight as a fishes armpit, but I find the bag method ok.

Cheers Andybear :lol:


----------



## Raumati (May 22, 2006)

I used selleys all clear on my scupper after reading an article in NZ fishing news.Two other tips the writer gave were to give the surface a light sand to carefully run a heat gun over the surface before applying the silicone to remove any traces of moisture.
The first time I tried to use it the transducer came loose on the trip home as I put the kayak on my roofracks upside down, I had a look and the silicone hadn't gone off inside the outer dry layer.I left it outside in direct sunlight for three days and havn't had a problem since.Another thing the article mentioned was that air gaps betwwen the hull and transducer cause corruption on the fish finder reading -so I used plenty of silicone .It looks like crap but works well.
Hope this helps.


----------



## JT (May 25, 2006)

And just how bloody good is New Zealand Fishing News as a magazine. 90 odd pages in an A3 size, full colour with a dedicated yak fishing space. It's all good and for only 6 bucks. Hard to source locally ofcourse.....and no I'm not on commission.

JT


----------



## varp (Sep 12, 2005)

Anyone know about the best gear to use with fibreglass. Was told Sikaflex 291....not so sure now.


----------



## andybear (Jan 15, 2006)

Doh.....Occy....

I have never called anyone on the forum a name.....as in name calling..

Go pick out one for yourself....do forty pushups, and stand in the corner.

People are all going to think we are mad around here

Cheers Andybear :lol:


----------



## Dodge (Oct 12, 2005)

varp said:


> Anyone know about the best gear to use with fibreglass. Was told Sikaflex 291....not so sure now.


Reckon you can just use your favourite brand, as GRP doesn't have the oily surface like plastic.

When i was fiddling with a glass half cab it got what was on the shed shelf as long as it was exterior quality sealant and never had a failure in a dozen years


----------



## andybear (Jan 15, 2006)

Sorry about the late reply to some questions re the sandwich bag.

I have found that if the sandwich bag is sitting in the "U" profile in the middle of the hull (where applicable to the make of yak), the bag will sit in situ quite well, with the cord sticking out of it, and the weight of the transducer holding it in place. I have also used a section of guttering rectangular in cross section for those applications where there is more likelihood of the bag falling over/spilling.

Please note: when using the bag only, I don't put the water in the bag until just before the launch, in case I roll the yak coming down to the beach. Even in quite lumpy conditions enough water has remained in the bag to give a signal. With the zip lock closed as far as it will go, you should not lose a lot of water!

I am considering using a different waterproof container, one which may possibly have a better contour with its surroundings. The challenge will be to see how far it will stretch, and whether or not it will roll around. I will not state exactly what at this stage, for fear of finger pointing, and someone calling me a dickhead. Subject container may resist transformation of shape, and I don't want to get a ribbing. I have not studded this matter very well. It could be in for a rough ride, so I will have to check mates.

Cheers all Andybear :shock:


----------



## Tim (Nov 11, 2005)

I reackon the franga will roll around too much andybear.


----------



## andybear (Jan 15, 2006)

Subject new idea........I blew it

Cheers all Andybear 

However the contact with the plastic surface was absolute, perhaps some R and D could resolve. I will have to think more on the matter


----------



## FishinDan (Jul 3, 2006)

andybear said:


> Subject new idea........I blew it
> 
> Cheers all Andybear


You had a good idea Andy but you blew too early.... No-one likes it when that happens :wink:


----------



## Tim (Nov 11, 2005)

Not that theres anything wrong with that, one must be protected when mounting transducers.

yes, it gets worse.


----------



## andybear (Jan 15, 2006)

Is this what they mean when you say "Hi jacked?"

Andybear


----------



## DougOut (Dec 31, 2006)

hey andy
don't supose you know any plastic surgeons that can get their "hands" on some used (but not abused) implants :wink: 
I reckon, size and shape would be just what your looking for 
Tim may have a spare from his blow-up doll


----------



## Tim (Nov 11, 2005)

I thought you said non abused? :lol:


----------

