Fiberglass Filler and Sealant

[Cy]

Hey,

I am going to start mounting my new sonar unit this week.  I don't know exactly how I am going to mount everything yet but I am pretty sure I am going to have to fill some screw holes from the old one.  What do you guys recommend to file holes in the glass?

I am also going to have to put on a transom mount transducer.  What is a good marine grade sealant to use for that?

Thanks,

Cy

[thedude]

depending on how big the holes are, get some 5minute epoxy mix up a good bit and let it set for 4.5 minutes... it will get pretty tacky and you should be able to pack it into the screw holes... use an old cloth with acetone or rubbing alcohol on it and you can wipe it smooth w/ fiberglass. If they are bigger holes, get some chopped fiberglass and mix it with epoxy to make a reinforced putty. www.uscomposites.com has everything you need for that... but i bet the 5 minutes stuff should work

i just use regular silcone to seal up my transom transducers.

[Waterfoul]

Hey Cy, come see me at West Marine in GR on Wed. afternoon... I'll set you up with everything you need to fill those holes.

I don't like regular silicone for anything below the waterline.  It will eventually fail you and let your transom get wet.  I prefer something like 3M 4200 or 5200... much more permanent and much better sealant against ANY water getting into your transom.

[MadWags]

I use the 3M 5200. It is expensive but it is certainly the best product on the market.

[thedude]

i have silicone on my jon boat that is 15 years old.. you gotta buy the stuff in the caulk tube that is clear, not the "bathroom & tile" stuff.

[Waterfoul]

Your jon boat is one thing... a 70 mph fiberglass cored hull/transom  bass boat is another animal entirely.  I just don't trust plain old silicone as I had it fail on two different occasions on my Baja over the years.

And when you gonna get all that stuff out of my truck?? 

[thedude]

jump a lot of beaver dams and muskrat huts in your 70mph bass boat do yah?
i can assure you my jon boat's transom has taken 10 times the beating any 'glass boat here has taken!

i've got it on my bass boat also... no problemos!

[Cy]

Can't you two ever agree and get along???  The real question is how long have you been friends?  Because it seems like you two have been friends way too long.   

[thedude]

he's not my friend... i just show him how to catch fish every once in a while.

and i will concede... i didn't think about at the time of posting, but you're probalby talking about mounting a transducer without screws? i use silicone, but also use self-tapping since its an aluminum hull.

[cr]

Cy when I traded my skeeter in I kept my SI unit and just put stainless finish screws in the old holes , the ones with a collar on them , looked OK . Any brand name marine grade silicone , 3m, loctite ,etc should work , just goop a lot of it on . P.S after reading this thread I now have "jon-boat envy". Jumping beaver dams sounds like a riot .

[robtheboatman]

The 5200 that Wags talked about is an excellent product.  Just make sure you have it where you want it, because when it dries, the stuff is permanent.  If you need more specific instruction, give me a call, and I will get with my fiberglass guy about your situation.
ROB

[Waterfoul]

Can't you two ever agree and get along???  The real question is how long have you been friends?  Because it seems like you two have been friends way too long.   

LOL!!  Yeah, we're friends... and ONE time he outfishes me.. ONE TIME.  And I was in the BACK seat that day.    But hey, we took home good money that day so I was o.k. with him outfishing me!  LOL!!

Anyway Cy, I just prefer the stronger stuff that adds adhesion to the waterproofing... 5200 is that product for me.  It has NEVER failed me... and like I said I've had silicone sealed holes leak in the past.  In fact, the trasom skimmer xducer for my dash mount fish finder is mounted to the transom with 5200... and no screws.