Aluminum Boat repair - Rivets?

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twostep

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I have a '80 16' x 60" flatbottom, riveted aluminum boat. Over 20 of the rivets leak.<br />What is the best repair? Weld? Has anyone had any luck with the Duraflex?<br />If you weld does it weaken the metal around the weld, causing it to fatigue?<br /><br />Thanks in advance for any help.
 

FlyBoyMark

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Re: Aluminum Boat repair - Rivets?

Twostep...this is from one of my earlier post. Use Screws that match the diameter of the rivets you want to use. The rest of the other types of repairs are hokey pokey:<br /><br />DO NOT WELD!(and this is coming from a weldor that fixes alum. boats) Use S.S. TRUSS HEAD phillips screws with flat washer and nylon locking nut on the back side. Drop of 5200 sealant around the screw head before inserting so that it squishes thru jus' a bit when ya push the screw in. Wipe of exterior with lacquer thinner soon as you tighten the screw. Use #10-24 X 1/2" size screw and drill out rivet with 3/16" drill bit. IMPORTANT! Remove all filings, champher all holes by hand with large 3/8" or 1/2" drill bit. USE STAINLESS STEEL TRUSS HEAD PHILLIPS screws. Box of 50 ea. should cost about 4.50, nuts 4.50, washers 2.50. You could literaly dissassemble your whole boat and put it back together this way with different size screw for different size rivets. I do repairs and restorations this way.
 

twostep

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Re: Aluminum Boat repair - Rivets?

I must ask, why should I not weld or use the durafix. Will the aluminum fatigue?
 

FlyBoyMark

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Re: Aluminum Boat repair - Rivets?

On an aluminum boat with thin skins or aluminum boats that are riveted, the sheet metal will eventually crack around the edge of the welds. In addition the heat will warp and buckle the hull around the welds. ALSO...if you weld a rivet head, it will enlongate the shank of the rivet and the rib or bulkhead behind it will start to seperate(if not completely melt away) and a gap between the two pieces will appear which will exacerbate the cracking proccess because the sheet metal is no longer supported properly. AND...on top of all this, it cost alot more to weld and looks like **** when done. Any goo or other quick fix amounts to the same thing. They DO NOT improve the integrity of the hull as do the screws. The screw not only look nice and is stronger, it matches the boat, any bafoon can fix it with a screw driver and 1/4" socket wrench with some 5200. The only appropriate weld spots are long splits or 90' corners and should be backed up with a piece of stainless steel or copper when welded using 5356 weld filler ONLY.
 

2008c50t

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Re: Aluminum Boat repair - Rivets?

Old post but great info. I don't doubt this is the best way to go for this type of repair.

I've done two rivets and still have a few to go. Some things to mention; When drilling out the old rivets I use a small center punch on the inside of the boat with the back of the rivet on a hard surface. Use the punch to start a pilot for your drill bit. It makes the rivets much easier to drill out, and keeps you from drilling too big for the screw heads.

Other than that this is a very simple and effective repair. I recommend it over any of the repair kits being sold. Fix it this way and you won't have to fix it again.
 

Silvertip

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Re: Aluminum Boat repair - Rivets?

Why not just learn how to "buck" the rivets and tighten them up. This isn't rocket science. It may take two people since your arms aren't long enough to reach from the center of the boat all the way around to the inside. Just Google "Bucking Rivets" , "Rivet Bucking" or similar words. You could also invest in a pop rivet tool and simply replace the rivets (you need to use solid rivets -- not the standard type).
 

98LSWON

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Re: Aluminum Boat repair - Rivets?

Drill ot the leaky rivets and install an oversized one in the hole after you ream it. You can dip the rivets in PRC to help them remain water tight.
 

FlyBoyMark

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Re: Aluminum Boat repair - Rivets?

Yes I'm still here lurking in the shadows...
New rivets are also fine and I DO use them quite a bit but I'm "in the business" and have all the tools and parts on hand. But most individuals will need a compressor, pneumatic rivet gun then try to find the rivets, which amounts to a fair sum of money jus' to fix the leaks or broken rivets. Where as, Truss Head screws jus' require a drill, screw driver and combo wrench.
Pop rivets don't fly unless its for VERY small non structural repairs. The large ones used for 3/16 or larger holes require a pneumatic puller or very heavy duty manual puller. Again...cost extra money.....
 

mthieme

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Re: Aluminum Boat repair - Rivets?

I've been down the bolt and nut route. Depending on where there are - open floor - these can be rude to step on, bump into, catch clothing, etc.
I would re-rivet. This has been the quickest, simplest one-man way for me.
 

5150abf

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Re: Aluminum Boat repair - Rivets?

Been a welder for 22 years, currently the guy #2 in the weld shop at Bennington marine, you can weld the rivet hole but it is really hard to weld what the rivet was holding, as stated, with that small of a weld eventually it will crack and leak again, then there is the dirt factor ect, I have done it and it is a real pain.

I would simply rebuck them, it is fast, easy and puts it back like it was built.

I have done it several times, couple taps with a hammer and a backer and you are good as new.
 

Bondo

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Re: Aluminum Boat repair - Rivets?

New rivets are also fine and I DO use them quite a bit but I'm "in the business" and have all the tools and parts on hand. But most individuals will need a compressor, pneumatic rivet gun then try to find the rivets, which amounts to a fair sum of money jus' to fix the leaks or broken rivets. Where as, Truss Head screws jus' require a drill, screw driver and combo wrench.
Pop rivets don't fly unless its for VERY small non structural repairs. The large ones used for 3/16 or larger holes require a pneumatic puller or very heavy duty manual puller.

Ayuh,.... I can Disagree with That...

Google up "Closed end Pop rivets"....

I've been using them for Years, with a hand-set pop-riveter, with Excellent results....
3/16" for my old Starcraft hull...
 

FlyBoyMark

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Re: Aluminum Boat repair - Rivets?

For exposed nuts and screw ends use "acorn nuts". Closed end pop rivets do work but they don't have the water sealing ability in the long run for "hull" usage. I use them extensively in aviation work for special purposes. They will elongate eventually and do not have the same amount of support as any other rivet unless you use a matched backup washer ..still jus a temp fix. Re-bucking I also do some times but there are still ones that are jus' sheared off or oversized holes from vibration and pounding of the hull. The screws in most case will NEVER come loose or shear. And again, most individuals with small aluminum boats do not have most of the special tools needed. SO.....simple drill, screwdriver and little open end wrench do the job AND it's still MUCH stronger. The truss head screws almost exactly match the rivets and look good.
Want more details on how rivets should be sized, fit and driven?

Qualifications:
Owned 30+ yr. welding & fabricating
aerospace/milspec/aviation/marine/structural business
Coast Guard certified weldor
3G unlimited structural
owned/custom built/operate boats to 38'
Commercial
Instrument
SEL&MEL Land
A&P
MSCNE

Any questions?
 

AZSenza

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Re: Aluminum Boat repair - Rivets?

as a 22 year aircraft mechanic (LOTS OF ALUMINUM Sheet Metal repair expirience) I have bucked millions of rivets, Just install them wet with sealant (Dip the rivet in the sealant to ensure you get squeezeout) naturally a plain solid AD2024 rivet is best, a blind rivet installed wet will work well too. You can use screws to keep the hull tight as you run down "Shooting" your rivets or you can spend a few dollars on "Clecos" they are specialized spring loaded temporary fastners that keep the plies of sheet metal together tight. Google them. Just make sure what ever you use, coat the shank with your sealant.
Rivets are nothing more than a cheaper, lighter alternative to a screw. A proper screw is always the strongest, but also much heavier than a corresponding rivet.
 

Tim Frank

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Re: Aluminum Boat repair - Rivets?

For exposed nuts and screw ends use "acorn nuts". Closed end pop rivets do work but they don't have the water sealing ability in the long run for "hull" usage. I use them extensively in aviation work for special purposes. They will elongate eventually and do not have the same amount of support as any other rivet unless you use a matched backup washer ..still jus a temp fix. Re-bucking I also do some times but there are still ones that are jus' sheared off or oversized holes from vibration and pounding of the hull. The screws in most case will NEVER come loose or shear. And again, most individuals with small aluminum boats do not have most of the special tools needed. SO.....simple drill, screwdriver and little open end wrench do the job AND it's still MUCH stronger. The truss head screws almost exactly match the rivets and look good.
Want more details on how rivets should be sized, fit and driven?

Qualifications:
Owned 30+ yr. welding & fabricating
aerospace/milspec/aviation/marine/structural business
Coast Guard certified weldor
3G unlimited structural
owned/custom built/operate boats to 38'
Commercial
Instrument
SEL&MEL Land
A&P
MSCNE

Any questions?

Yes, a couple.
What about galvanic considerations? and Why is setting solid rivets regarded by so many as dangerous ground?
I do not think anyone is questioning your qualifications, but some of us have had different experiences which i do not think are any less relevent.

I own an older aluminum boat and replaced the transom last year.
The only DISASTER in the whole process was one corner that I cut....rather than use aluminum fasteners in one particular spot, I listened to someone's advice (well-meant I am sure) who said stainless steel screws would be fine.
So I used them... with lots of 5200 around them, too.

Well, there is already significant corrosion around the screw heads...and they are above the water line, although subject to lots of spray...and this is a fresh water lake. I would not want to imagine what salt water would do.

If I have to do this again....and I do have a 12 foot cartop to do next spring,
the only fasteners i will consider are aluminum rivets...and I will likely go with the solid variety.
The tool to set these is available for less than $25-, and the rivets are not hard to find. For the small number that most DIY ttypes will need to handle, hand tools are fine.

Rather than post a list of my qualifications, I'll simply say that perhaps s/s fasteners are OK in some applications in aluminum boats... but for me it will be someone ELSE'S aluminum boat.
The manufacturers of my particular boat....a Florida company who made the best small tinnies that I have ever seen, used only aluminum fasteners...screws where they had to....otherwise solid rivets.
40 years later, not one of the rivets has loosened...
That's good enough for me.
 

TheBlacksmith

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Re: Aluminum Boat repair - Rivets?

In my experience, most boats with with leaking rivets will also have spider cracks extending from the rivet holes. I remove the the rivet and weld the cracks with a synchrowave tig, redrill and new solid rivets. If there is no cracking and the rivet is not worn out too badly I use a rivet set on an air hammer with lower pressure and a good helper on the bucking bar inside.
With ear plugs in.
To check for leaks I have a custom set of horses with braces, The boat is put on and filled with water, get it about half full and you can find all the leaks quickly.
Just my two cents
I think this might be my first post here, great forum.
 

AZSenza

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Re: Aluminum Boat repair - Rivets?

What kind of sealant did you use? MANY sealants are corrosive to aluminum, Rule of thumb, if it smells anything like vinegar-DONT USE IT ON ALUMINUM, as it will corrode. Most sealants you buy from automotive stores have it in them, it needs to say "Safe for Aluminum " on it. There are many grades of stainless, depending on the amount of nickle in them. It needs to be an aircraft or marine grade. Also, very important is Aluminum corrodes very fast. If the coating (Paint etc) is removed it needs to be chemically treated, either with an alodine and etch or a self etching primer. Zinc Chromate used to be the ticket but the EPA has all but shut down the availability of it. There are a few recent alternatives to the chromate, sold at aircraft and marine suppliers, its green or yellow.
 

FlyBoyMark

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Re: Aluminum Boat repair - Rivets?

OK!......FOR marine use; I treat the repairs like aircraft repairs. If its spider cracked, usually I jus' drill it out one size bigger and still use SS Truss screws. The screws really bind the material very tightly as a general rule and do not allow the spider cracks to propagate If its a REALLY big spider crack 4"X4" lets say, I back up with similar material and put a bunch of little flat head flush SS screws with nuts (#4's) sometimes I use little flush rivets if the patch is exposed inside the boat. ALL fastners except for aluminum rivets, I use a little dab of 5200 which acts as an insulator. In addition as I've stated elsewhere in this forum, I acid wash, alodine, chromate. These extensive repairs I do only on high end boats. Most little jons or v's, its not neccessary to go through all this except for maybe for the 5200. If its a spot where I'm using rivets or an above waterline screw on smaller boats, I jus' goo up the hole and fastner with aircraft zinc chromate primer spray and fasten while wet.
One of the problems with galvanic corrosion is a loose fit. Tighter the connection in materials, the less problems.
Welding on the bottom of a "working" hull should be avoided as a general rule unless its REALLY neccessary.
And again, dinky little boats with trolling motors or 2hp with big cracks can be welded up with no problem. There generally is no "working" stress on these hulls.
 

FlyBoyMark

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Re: Aluminum Boat repair - Rivets?

I forgot to mention: That nasty zinc chromate is still available in aviation grade (Tempo) spray cans ONLY.
Get my stuff from Aviall and couple of other small shops in Miami.
 

bassboy1

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Re: Aluminum Boat repair - Rivets?

And again, most individuals with small aluminum boats do not have most of the special tools needed.
What? Your average boater does not have access to two large hammers, or one hammer and a chunk of steel billet?

You can get flat rivets, which do not need a concave punch. Just use one hammer as a bucking bar, and use the other to hit with. Have had to do this on occasion when in a bind. It WILL work.

Or, conventional round top rivets work fine too. The flat hammer will slightly flatten the round head, making the cosmetics not as nice as a factory hammered rivet, but you have to really look at the rivet to notice that, and it is still 100 percent functional.

You do not need fancy equipment to pull 3/16 blind rivets. I have pulled well over 2500 of those on a 20 dollar home depot pop riveter. They aren't exactly weak either. I used them to completely rebuild the deck structure and hatches and all in an aluminum bass boat once, and they will hold a heavy load just fine. I am not talking about holding the sheet onto the structure, but building the structure with these. This boat regularly will fish a couple 200 plus pound people on the bow deck, and when the truck is in use, we have had to use this boat as a utility trailer, and those "non structural" 3/16 pop rivets hold large loads just fine.

I have also used them, in conjuntion with a little 5200 in thru hull applications.

Qualifications:
Owned 30+ yr. welding & fabricating
aerospace/milspec/aviation/marine/structural business
Coast Guard certified weldor
3G unlimited structural
owned/custom built/operate boats to 38'
Commercial
Instrument
SEL&MEL Land
A&P
MSCNE

Any questions?

Your attitude has a lot of room for improvement. I am not disputing your credentials, and I commend you for the effort needed to gain all that. Also, I see nothing wrong with your method of doing this. It works, but it is not the only way. You seem to be so far up on your high horse that in your view of things, because it worked for you, it is the only way to do something. And, because you do have credentials that exceed that of some of us, your way is the only acceptable.

If you had posted once with your idea, that would have been acceptable, or if you had defended your post when/if somebody called your method out particularly (not that it happened in this case - more of a what if scenario). However, you posted your idea, then kept calling down EVERY other idea that was written down, attempting to stomp it into the floor, and kept pushing your own idea as the ONLY one.

From the looks of it, and I haven't searched any of your other posts, but you have developed a nice little reputation, from this one thread alone. Take some time, get an attitude adjustment, and people may start listening to your ideas (not your "facts") on how to do something.
 
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