Aluminum Tunnel Hull with braded seams

[craddock1]

I just bought an aluminum tunnel hull. The seams are braded and the hull is beat up pretty good. Will fiberglass hold on aluminum if it needs repair or seam sealing. I can't see any holes in it but the seams do not look real healthy. I am thinking a 4" fiberglass strip the length of the seam if it leaks. I got the boat with a 30 horse Evenrude and a foot control trolling motor really cheap so I can put a few bucks in it. Thanks in advance.

[poisonpits]

when i was in seadrift texas we use to put fiberglass bottoms on aluminum air boats to keep from sanding the aluminum off when pulling out on the beach,s at the gulf beach.we use ground up dry corn to sand blast the bottoms before glassing.

[drpepper]

If you have a bad weld seam, find someone to weld it for you.... do it right.

[craddock1]

All the seams are Braded. Can You weld a braded seam. The glassing sounds good I have always had good luck glassing holes and leaks in fiberglass. Thanks.

[tbird]

What the heck is a braded seam? Do you mean it is brazed with an aluminum brazing rod? I have seen this used to repair trim and fairings on aircraft but never for a structural part. Probably work to stop a leak but I wouldn't trust it to hold a boat together.

[craddock1]

This is not a welded boat. They put the brads through the overlaped seam about 1 inch appart and braded them on the inside. Brads are notorious for working loose and leaking. You have to be old to remember braded boats.

[tbird]

Well I ain't no spring chicken but that's a new one for me at least it sounds like you could still weld the dang thing and not worry about it coming apart. Years ago I used gluvit to coat leaky boats I am sure there are better epoxy products now.

[drpepper]

I thought maybe he was talking about a "stack of dimes" weld. silly me.

Have you seen that screen door bottomed boat commercial? lol

[arky]

Those are rivets and if you weld the seams you still have a leak at the rivets.
You can glass to alum but the alum will need to be cleaned really good. Sand blasting with pecan hulls or ground corn works well then glass quickly or it will oxidize.
I put spray bed liner on a old riveted jon boat and it is the same as glass, the alum has to be very clean.
I guess the stuff they used on the boat with the screen door bottom would work.

[Mark J]

First order of the day...cost effectiveness.
Is it more cost effective to go to the trouble and expense on a well used banged up boat or sell it and find another?

Polyester nor vinylester resins will bond with even super clean aluminum. Hell, it won't bond with a porous material like wood.
You might achieve some degree of "sticking" but it is a very poor bond.
Then you have the expansion rate of the aluminum which is going to be very different then fiberglass.
If what is covering the aluminum can't expand with aluminum how is it going to bond?

Then the issue of laying the glass over the seams. If you've laid much you know that it will not conform to any shape, bump, or ripple you throw in it's way, like a brad for example.

But the most important thing to realize and alot of boat builders don't get it themselves...Fiberglass doesn't waterproof a thing.

About a month ago someone was down at my shop and saw a center console I built for someone and it was just in the glassing stage.
"Oh look honey he glasses it to make the wood waterproof"

"Um, no sir, I glass it to keep your big ass from falling through the center of it when you hit that wave running 40 mph."

His wife thought it was funny as hell.

Anyway, that's my two cents. Bottom line, what it's worth to you but the last thing I would put on it is fiberglass.
It doesn't BOND with aluminum so what's the point? You aren't going to get any strength out of something that doesn't bond.
There is a relatively new epoxy works well on rivets. It doesn't bond with aluminum though. It'll stick to aluminum and is flexible.