Question:
I have a 1983 Bluefin, 16' open front boat-90 hp Johnson
the aluminum river boat leaks
gets a lot of water in it after an hour on the water
No holes, large dents, etc.
When I put it in the driveway, a couple of seams leak and a few of
the rivets.
What can I do? Is there a sealer I could buy?
Answer:
-Depending on how bad the seals are I would use 3M 5200 or Marine Tex - I
think the 5200 is more flexible which may be important for aluminum boat.
Scrape out as much as you can of the old sealer to make room for the new
stuff. Then clean like crazy to ensure the surfaces are clean. Use acetone
or methyl hydrate. Let it dry thoroughly. When you install the new sealer
work it into the gap as much as possible - cut as fine a tip on the tube as
you can. Clean up the excess as soon as finished - I left some 5200 for a
day once and had a devil of a time getting it off. They say it takes 7 days
for full cure and I found that to be true. Don't move the boat for a week
or the sealed space may open up a bit. If temperatures are below what it
says on the package the time to cure goes up a lot and it may not cure at
all - maybe wait till spring?
I have had leaky rivets on aluminum boats but never leaky seals. Is it
possible that some other problem exists? Maybe someone spilled some kind of
solvent in the boat that ate the sealant or used solvent to try to clean
the hull. Another possibility is too much flexing going on. Has something
broken or otherwise failed that is letting the hull flex too much near the
seal leak? Has the boat been improperly supported on the trailer to make it
flex too much? Is the boat on a roller trailer? I am a firm believer in
bunks for aluminum hulls. It seems to me that rolling flexible material
like aluminum boat hulls over rollers is damaging because it over-strains
the rivets and seals as they pass over each roller.
The rivets are easy - they can be re-sealed by hitting them a good rap or
two. The best thing is to use the proper fitting head on an air-hammer but
these are tough to find and I have had good luck with plain hammers. Use a
1 or 2 pound hammer on one side and have someone hold a heavier, 4 or 6
pound hammer on the other side. No need to over do the force. The time I
used the proper tool the boat didn't leak again for a year till I sold it.
The time I just used hammers some rivets leaked a bit but not nearly as
much as before. Be carefull, aluminum rivets are very soft when hit with
heavy hammers. Someone told me that most aluminum boats have no sealant at
all under the rivets, the tightness of the rivets is all that seals them. I
never saw any sealant under the rivets of my boats but I did hear that some
have it. The big hassle may be getting at the inside of the hull to do the
rivets. If there is a floor or other interior stuff you will have to remove
it and put it back. Lot of work but not brain surgery.
Another thing - my old boat got a lot of water in it and it turned out
to be from spray from the motor while underway. The motor well was not
sealed at the transom - a little silicon sealer solved it. Don't use 5200
for anything you may ever need to take apart.
- I'll add one more, if
the boat had been beached a lot or if it had gotten scraped or gouged, you
could have a actual hole in the aluminum somewhere (my 12' AL jon boat had
leaks in the formed strakes in the bottom at the transom from getting
dragged up onthe bank for many years).
I fixed them by soldering/filling the leaks with the low temp AL solder that
is available (it's for sale in lb packs at almost all of the boat shows,
Bernz-o-matic sells a few sticks for a few bucks at Home Depot).
