Boat Sealant

[CrustyMono]

Ok so I bought a new boat yesterday and the person whom I bought it from warned me of small leaks in the rivets. My plan is to use silicone caulk on the inside to seal that and use jb weld on the outside. Also, i will use flex seal overtop and then cover the boat's underside in truck bed liner from harbor freight. does anyone know if this will work or if there will be issues? thanks!

[slonezp]

Use 3M5200 for the sealant

[flyfisher]

Adding the truck bed liner is going to add a lot of weight to the boat and also since it is textured i also imagine it would increase drag on the bottom. 

I'll second the 3M5200 for the sealant as well

[Catt]

32 minutes ago, slonezp said:

Use 3M5200 for the sealant

 

13 minutes ago, flyfisher said:

Adding the truck bed liner is going to add a lot of weight to the boat and also since it is textured i also imagine it would increase drag on the bottom. 

I'll second the 3M5200 for the sealant as well

C'est Fini (it's finished).

[fishnkamp]

Go here and read a long posting by Chris, my friend. He has successfully done this just this past summer. The boat has since been out fishing over a couple of dozen times and is completely dry. You can also shoot him a message. Kris is a member here as well but has documented his process in depth on that site. He used 5200 around every rivet , inside and out, then painted the hull inside and out with bedliner paint. It is completely dry. The boat he has redone was given to him free by a friend of a friend, and it suffered abuse since that owner had installed decking and used pressure treated lumber. Wherever the pressure treated wood contacted the hull there were tiny holes caused by the chemical used on the wood to treat it.  You would not believe how nice the boat is now after three months of hard work.  This time a complete frame was made to support a two level floor out of Azek which is plastic wood.  Here is the link to hi new old boat. http://www.*/bass-fishing-forum/index.php?topic=130307.50  

[WRB]

Bucket and sponge.

Rivets will continue to leak, aluminum oxides are extremely difficult to clean for sealants to bond. Covering up a problem doesn't solve it.

3M 5200 marine sealant is good.

How many rivets are leaking?

Tom

[Catt]

Clean the aluminum surface with a good cleaner using Scotch-Brite Hand Pads to remove all dirt, old paint and oxide from the surface. When sanding I prefer 80-100 grit it gives better tooth and paint adhesion.  Sanding must be taken into the best previously adhered surface in order to have the new coat of paint hold properly. Start with an orbital sander; finish by hand with Scotch-Brite Hand Pads. Rinse thoroughly with clean water & let dry completely.

Apply a coat of acid etch primer following the mixing and application instructions to the letter.

Apply  3M5200 sealant

[Fishing Rhino]

All the above are good suggestions.  I'll add one more.

A leaking rivet is usually a loose rivet.  You'll need a five pound sledge hammer, and a regular hammer, and, someone to help.

Have the helper hold the 5 pound sledge against the head of the rivet while you hammer lightly on the other side of the rivet.  This will tighten up any looseness in the rivet and/or the joint.  It will not only compress the pieces that are joined against each other, but it will also expand the rivet to reduce or eliminate any gap between the rivet and the aluminum sheets.

Some old time wood skiffs are made using a rivet of sorts.  It is a copper nail, and a copper washer that just fits over the nail.  Where the wood overlaps, a hole is drilled that will allow the copper nail to pass through.  When the nail is fully inserted with the head of the nail on the outside of the hull, the copper washer is slipped over the nail, the excess of the nail is snipped off with side cutters, leaving a sixteenth to and eighth of an inch of the nail exposed beyond the washer.  A hammer is held against the head of the nail, and the remaining shank of the nail his struck with a hammer.  If memory serves, these are spaced about four inches apart, and when done properly makes for a watertight joint between the two planks.

When the skiff gets old and has endured many years of pounding on the water, you can repeat the process with the copper "rivets" and retighten the joints.

Galvanized nails were also used to join wood lapstrakes together.  The nails used were about a quarter of an inch longer than the combined thickness of the wood strakes being joined.  Then the excess would be bent over and using the same process as the copper rivets, a heavy hammer would be placed against the head of the nail and using a nail set or punch, the bend would be struck, bending it more, until it was just below or flush with the surface.

You could also tighten those fastenings if needed by backing up the head, and bending the other end of the nail a little more.

[DelcoSol]

They make water tight rivets. Has something to do with how they are pulled when installing them, there isnt rubber or sealant on them. Why not just replace the rivets?

http://www.directindustry.com/prod/gesipa-blindniettechnik-gmbh/product-4469-417795.html

[Fishing Rhino]

When the rivet is compressed, it expands the rivet around the shank and against the hole.  That is why hole size is critical (according to the site you posted).  The problem with replacing them is that vibration and pounding on the water has "worked" the hull which expands the hole and also grinds away at the shank of the rivet.  In addition, drilling, if it runs off center will expand the hole beyond the rivets capacity to expand and seal the hole.

Leaving the existing rivets in place and hammering them may seal the leak.  It depends on how much the hole has enlarged.  I have no doubt in the ability of 3M5200 to provide a positive and lasting seal, particularly if it is applied to the inside and outside of the hull.  It remains flexible after it sets up, but will do nothing to tighten the hull. 

My first step would be to hammer on the rivets, then apply the 3M5200 as insurance. 

[Catt]

3M5200 or weld it!