Sealant???

[tinnieboy]

I am about to fit an adjustable tranducer mount to the transom of my tinnie...what should I use to seal the holes I drill in the transom? Silastic? I have been told this will cause corrosion is that right? I will use aluminuim pop rivets so there will be only aluminuim used in the whole process.
Cheers Trent

[Morlers]

Hi Jacksdad

Watch the type of silastic used. Most are acetic acid cure that will eat away at the alluminium. Use only a neutral cure type like a roof and gutter sealant made specifically for metals. Also boat shops sell a product called 'sikaflex' that's neutral cure and specifically for boats. Hope that helps.

:) :)

Morlers

[revs57]

Sikaflex...way to go!

[-spiro-]

sikaflex works well on alloy 8-)

[Dehydrated]

I have used Selleys Marine Silastic for that exact purpose without any problems.

Cheers
Don.

[familyman]

If you are using the sliding stainless mounts from bias etc provided they are clean and your alloy is clean then just use sikaflex high strength adhesive and glue it on . ::)Dont bother with the rivets.
Before everyone says 'yeah right' try this - get 2 pieces of thick sheet metal same size as your mounting ,smear completely with sikaflex ,push together then let it set for 24hrs.After that try getting them apart- you will destroy the metal first :o
cheers jon

[revs57]

Yep, the familyman is right....sikaflex is the go!!! The only stuff for alloy...and no need for rivets form your purpose...just follow the directions, clean and dust/grease free and away ya go - no holes
Rhys

[dugong]

why not just get a alloy transducer bracket welded to the transom??, no need to worry about leaks.
if you use rivets, they must be the sealed type of rivet and not have a steel shank
most rivets are open type and even the alloy ones can have a steel shank
cheers

[bluewaterbandit]

SIKAFLEX BEST SEALENT

[bevnarch]

same here sikaflex is the way to go and handy around the house

[FNQCairns]

Family man is right. Actually sikaflex is the second best marine sealant the 3m 4200/5200 is better. The 5200 will take a section of the gelcoat off before it gives, not a nice experience, the 4200 stays a bit rubbery and can at least be removed later.

Another way is to glue a portion of plastic chopping board to the hull with any of the above urethanes and screw to that, gives more surface area for a bond.

I will be mounting all pumps, fuel filters, pickups etc to the boat using only 5200 and plastic chopping boards so no screws into boat needed. I will even be securing the batterys to plastic board glued to the floor.
Just beaut stuff but get it right first time. cheers fnq

[falcon01]

sikaflex 291 is the marine one and it is excellent stuff used it as a jointing compund
on all my stainless screws works a treat. Can get it att bunnings etc any good hardware

[Wyoming]

Yep - Sikaflex is the way to go AND you can paint over it, unlike silicone.

The DOWN-SIDE is that it comes in a specially designed cartridge that secretly puts some of the product on to your hands and onto your clothing when you least suspect it. I'm not sure how they do it, but I'm sure they have scientists designing the packaging with this special leak feature.

[SCOTTYGC]

i had a bracket weled to the back of the boat at the local alloy weler

cost $20
no holes in the boat

tip: measure twice ,drill once

scotty

[SeaJay]

Or just shoot through your hull and avoid transducer damage. I siliconed my Humminbird Matrix 27 transducer to the inside of my 4.75m Sea Jay hull as a test and found the performance so good I haven't touched it since.

Took me about 60 secs to do.

[dnej]

dugong and scotty have made the best point, why put holes in your boat, when you can weld on a U shaped bracket, say 75mm wide, then attach your fitting to the bracket. Doesnt matter how many holes you put in the bracket.

I wouldnt go any other way. Use a bit of 6mm plate, bent at a less than 90% at the ends, to form the U. Should stand off the boat by about 30 mm.
Weld on that bracket, and away you go. Quite handy also , for making adjustments.
David

[warrior]

i have used the sikaflex range for years,there is no better product,just as the men up top said just glue it on with the product i have torn metal apart before the sika has released cheers allan.