Mounting sounder transducer to boat

[rajawolf]

Hi Guys..what is the best way to mount the transducer to the back of the boat..mine is fibreglass and I dont like the idea of drilling holes or using self tapping screws.

The mounts have slotted holes for adjustments, but if u need to adjust them ...that means the sealant will be broken, and I would worry that after resealing that it will not be a good seal and may leak. I just dont need the stress thinking all the time this may happen.

As you can see I am stressing already.. :-[

[gogecko]

my Hummingbird came with some pretty good instructions on drilling into fibro and sealing. Do you have instructions? If not, go to a few manufacturers websites. They usually have manuals online that include mounting trannys.

My boat is aluminium, so I cant be any more help than that.

[Poseidon]

There was a post made here a little while ago that described a good way to do this without any holes.
It mentioned mounting a section of that plastic cutting board material to the transom using sealant (like sikaflex) without the use of screws then mounting the transducer bracket to this material rather than the transom.
This way you can move the transducer around on the board if you need to without any holes in the transom.
Not sure if the context of the post related to fibreglass or aluminium but it certainly sounded like a good option.
Someone else may remember the location of the post.
Regards Cameron

[Robbo_Townsville]

I was lucky I just upgraded my sounder (with a sounder of the same brand) and bingo all the mounts from the old sounder fitted the new one even the old power cable.

A bracket fixed to the transom would be what I would with a glass boat.

[rajawolf]

I have figured out what i want to do now, and it involves using sealant of some kind to stick a mounting to the transom, and then screw to that. Has anybody had any experience with different sealants and their holding strength..liquid nails would be the go ...but no good in water. ;).

I have tried doing a search on here but, sometimes the sight is so slow and have had no luck.

[nevd]

The strongest readily available adhesive I am aware of is Sikaflex 252, but to do a strong job, you also need the Sika Primer 210T and an alcohol based cleaner.

[Fishin_Dan]

Why couldn't you fibreglass the board onto the transom?

[Kiktz]

I have not had a good read of everyones replies,
Why dout you Hull mount it.................
With thsi you get a better reading as well

[Sportfish_5]

Young Phillip Thompson is the king of sounder installations in fibreglass boats ::)

You will need to drill the transom and either mount the transducer straight to it or buy an adjustable bracket and mount that to the hull and the transducer to it.

umm - dont try and use only sikaflex to stick it too the hull :o That transducer for the 107 is quite big and would come off.

No dramas drilling into the hull - just make sure you pick somewhere with enough length for the self tappers and use plenty of Sikaflex to seal it all up. Ohh - you will need to drill another set to mount the speed wheel on the other side. Also the connectors on the Lowrance are NMEA 2000 and are quite big.


Good luck with the install ;)


Cheers,

Greg

[rajawolf]

Thank's everyone ...

I made up a bracket from cutting board type material drilled some holes and inserted bolts from the side that will be sikaflexed to the transom, to make the bolt heads flush for the mating surfaces I did up the nuts on the front side very tight, and applied heat with a pencil blow torch to the bolt heads causing them to melt their way flush into the mounting material, which locked the head into a plastic sort of hex keyway.

The reason I did this is cause the mount slots for the lowrance are way to big for self tappers.

I then had to bite the bullet and self tap this mount to the tansom but I counter sunk the screws so i could apply sealant to the screw heads that would act as a plug.

I am not that good at explaining what i did :-/ so will take a pic and try and post it...a picture replaces 1000's of words. :-?

Again thanks for the help.

[steve_n]

If mounting anything to the transom of a fibreglass boat it is a good idea to drill oversize holes and fill them with good epoxy resin. Then when set drill the holes for self tappers into the epoxy. that way the transom remains sealed. Even when using this method I still seal the surface with sikaflex. ;)
Cheers Steve

[grumpyoldman]

Sorry to be a "kill-joy" but I tried mounting some nylon cutting board material on to a lump of timber to use as a bait board and found that it split (after 1 season) where I had drilled and screwed. I think you may have been better to have used marine ply and sealed that. I've got a 107 which I haven't installed yet but I'm going to test a "shoot-thru-hull" installation before I start drilling holes in the transom. Much easier to fit, no holes to drill and no risk of busting transducer, even tho' I not using a trailer.

[rajawolf]

I should have explained the cutting board material I used a little better then I did .....it was a nylon/plastic type block about 3/4 inch thick..you can get them in many thickness's,and colour's, colour seems to relate to thinkness.

I think they use them for packing under cement slabs or something...my son use's them at work ...I found them in the garage, and stole one.:)