Transducer mounting!

[ejj44]

I installed a new depth/fish finder in my boat this weekend. I read and used the installation directions that came from the manufacturer, which involved drilling holes in the transom. It is a newer fiberglass boat. I am pretty sure everything went well with the installation except I am now second guessing my decision to use a high grade silicone sealant instead of a marine sealant. I was not able to find any marine sealant so instead of waiting to find some---I was maybe a bit impatient and went on with the job. I have read all lover the internet now that I should have used only the marine sealant but have also read and been told by a couple people that this should be ok-to keep an eye on it. Anyway, my question for the more wiser and more experienced members of this forum is ... Should I leave as is and just keep an eye on it? -OR- Is it smarter to remove the screws and remove the applied sealant and re-install a marine sealant and tighten the screws again?

 

[BWT]

Re: Transducer mounting!

Personally I do not recommend using silicone anywhere on a boat except for glazing polycarbonate windows. All the packaging on the silicone says it can be used but my experience is that it just doesn't hold up. If it were me I would remove your hardware, clean it REALLY well to remove all remnants of the silicone and use 3M 4200. A little dab over each mounting hole and a dab on the tip of each screw as you drive them in. You should see a little excess around each screw head as well as some oozing out behind the mounted part. Either let it cure overnight and cut off the excess or wipe it off while still gooey. Personally I like to let it cure and cut it off (cleaner install).. Hope this helps!

 

[ejj44]

Re: Transducer mounting!

Thank you for your quick response!
By taking the screws out and back in again, will the hole that was drilled stay so that the screws will be tight again?
Thanks again!

 

[BWT]

Re: Transducer mounting!

yup! as long as the screw did not strip the hole when you mounted the first time it will hold just fine. Remember the screws need to be tight, but not gorilla tight Fiberglass is strong stuff..

 

[ejj44]

Re: Transducer mounting!

Great! I am going to re-do so it is the correct way! I just need to find some 3M 4200 sealant!

 

[ejj44]

Re: Transducer mounting!

One more thing, why do you suggest 4200 versus 5200?

 

[BWT]

Re: Transducer mounting!

many hardware stores carry it, otherwise you can order online as a last resort... Could also try contacting a local marina. Good luck!

 

[BWT]

Re: Transducer mounting!

5200 just just too strong of a bond and isn't necessary. Chances are that if you ever need to remove this part down the road (and you will as hardware should be re-sealed every 5-7 years) you could damage the part trying to remove. I don't use 5200 for anything that has a mechanical mount (screws or bolts).. They have similar properties for sealing, 5200 is more for bonding (permanently) while 4200 still has some adhesive strength but is mean to be able to removed if need be.

 

[Woodonglass]

Re: Transducer mounting!

I would suggest Cleaning the holes, screws and hardware with ACETONE before re-installation. We recommend the 4200 over the 5200 because it is semi permanent incase you need to remove it later. Make SURE ALL remnants of that SILLY KONE is gone before re-installation, including the inside of the screw holes. Use ACETONE soaked cotton swaps or tooth picks to get in there and clean it out.

 

[ejj44]

Re: Transducer mounting!

Got it. Thanks again! Hope to get this done so boat is ready for weekend.

 

[ejj44]

Re: Transducer mounting!

Last question. I am having to order it and it may not get here in time for the weekend. Would you say I am ok to use the boat with what I have?

 

[Woodonglass]

Re: Transducer mounting!

Yep, Go have fun and do it after the holiday. NO permanent damage will occur. Coat the screw really well with the SILLY KONE and use a tooth pick to poke it up in the holes too. Really slather it in there. Get a lot of squish out. It will coat the wood and keep the water out. Makes it harder to clean up later but it will protect you for the holiday. HAVE FUN and ENJOY!!!

 

[ejj44]

Re: Transducer mounting!

Thank goodness! The family would sure be disappointed in me.
Thanks again!!! and have a great weekend!

 

[Capt'n Chris]

Re: Transducer mounting!

Actually, your fiberglass is very delicate. The constant dynamics of the water created by a boat at speed tug and snatch at the transducer and its mechanical fasteners. Be wary of potential leaks (regardless of the efforts made in sealing) created back there and, unfortunately, are generally found much too late. Read your boat manufacturers warranty statement, which, even if beyond the warranty, is great information for the life of the boat. The "rehab" sections of this boating forums and many others should be able to shed some rather disheartening light on the damages created by water found in the hull.

 

[ejj44]

Re: Transducer mounting!

That pretty much scares me but thanks for the starch reality of it all. I would sure love to hear more opinions on this. Thank you.

 

[ejj44]

Re: Transducer mounting!

I found some 3m 4200 fast cure and think I will be taking to screws out tonight, cleaning with acetone and using the 4200 to seal the screws this time. At this point, because I want to use the boat this weekend, I am only worried about the 2 screws for mounting the transducer and the 2 screws for the clamps on the wire running up the transom. There is another hole, where the wire goes back into the boat, drilled above the water line that I used silicone sealant on too but think I will wait until after the weekend to re-do that.
I will fell much better after all this knowing that I will not have a any leaks. It probably would have been ok to wait until after the weekend but since I found some 4200, I am going to take an hour or so and carefully re-do and get it right. Cure time is 24-28 hours so we should be good with that. Thanks for the help and keep the posts coming. I really appreciate the advice on here.

 

[Cadwelder]

Re: Transducer mounting!

That pretty much scares me but thanks for the starch reality of it all. I would sure love to hear more opinions on this. Thank you.

Well you asked for another opinion...so this is mine. I don't put any holes below the waterline that aren't absolutely necessary, I use "shoot thru the hull" transducers. You loose a small bit of sensitivty but it's never been a problem for me. But you are past this point so the advice given here is very sound the 3M 4200 is a top of the line marine sealant.

 

[RMasters]

Re: Transducer mounting!

Good thread, am planing on installing my unit this weekend, all this input helps a lot.

I like 3M. I hate and avoid under all circumstances drilling holes.

Ahoy!

 

[Woodonglass]

Re: Transducer mounting!

Well OK, IF you Really want to KNOW how I install things in a transom, I drill OVER sized holes, fill with Thickened epoxy, Re-drill and anchor my hardware into the epoxy. That way I never have to Worry about water intrusion via bolts or screws.

 

[Kotte]

Re: Transducer mounting!

^^^ I like that idea