A sheet metal riveting question

[tunnug]

I read that you plan on using a steel backer, keep in mind that aluminum and steel next to each other will cause dissimilar metal corrosion, if you can I'd use an aluminum backer, if not you'll need to use some adhesive to separate the two metals.

[starmac]

The backer is held in your hand, it doesn't stay with the rivet or metal.

[starmac]

[QUOTE=shaper;4269664]Stay away from the air chisel, it hits too hard and too fast. You will need a rivet that fits the hole tight. You should put it in wet with a sealer. Do not use a selastic. when curing it gives off a gas that eats aluminum. I would use a (A) rivet It is soft and will fill the hole best. Two hammers will work. Put the rivet in from the outside with the sealer on it and in the hole. Have a friend push the big hammer hard on the head of the rivet, he should hold the pressure until you are finished. Now you use the smaller rivet and crush the tail of the rivet, don't let it bend over. You are done. That is the primitive way. If it was here it would be a 30 second job. If you have the time to wait just pm me and I will send you the rivet, just let me know what size the hole is. Look for the number on the drill bit.

shaper
retired aircraft inspector.

Why do you say to stay away from an air hammer, the only planes I helped put together we used an air hammer? We use them on aluminum semi cabs too.

[EDG]

You do not need a special tool to set an aluminum rivet.
You need 1.5 times the diameter of the shank projecting through the work.
Back up the factory head and mash the rivet shank to a flat head.

At one of my early engineering jobs we set millions of rivets in assemblies to hold floating nut plates.
All the rivets, both dome head and flat head, were set with a flat head on the shank. It was all military hardware that complied with military specifications.

[lightman]

Starmac's post reminded me that the bodies on Peterbilt trucks are put together with rivets. You might look for shops that repair over the road trucks. Aluminum rivets are not hard to do though. A buddy and a couple of hammers will have you floating again in no time. Like the stick idea, it got you by ok!

[shaper]

starmac. The item i said not to use is a air chisel . Big difference between it and what you and I have used to install rivets. Air hammer, air riveter, rivet gun all the same. The air chiseler is hard to control especially so for someone that has never installed a rivet. It is a good tool to own if you plan to cut old exhaust pipes off a truck.

[frkelly74]

You could put a close fitting bolt through the hole with a nut and some silicone sealer. It would hold till you can get a proper fix done on it.

[Soundguy]

You could put a close fitting bolt through the hole with a nut and some silicone sealer. It would hold till you can get a proper fix done on it.

Especially a washer headed bolt that had a bonded gasket or flat faced oring.

[AllanD]

Regular pop-rivets may very well leak, but there are "blind rivets" available, I have used these on both corrugated iron and IBR profile roof sheets.

All "pop-rivets" are "blind rivets", the term you are looking for is "closed-end rivet"

And while a pol rivet (closed end or not) can be used to replace a rivet in a boat it requires some special care.

First the rivet must be all aluminum!

If a steel bodied rivet is used the boat will corrode the rived out of the hole
If the Mandrel (the pulling stem) is steel the rivet will corrode from the inside out.

There are advantages to solid aircraft rivets, but "bucking" them into place is not one of them.

[skeettx]

https://cottagelife.com/outdoors/how...ets-in-a-boat/
Mike

https://www.youtube.com/watch?v=gipz4We-aFk

https://www.youtube.com/watch?v=PdPr6D5J4-8

[Ballistics in Scotland]

What shape is the head on the outside of the boat? If it is round headed, a punch with the same size of hemispherical hole (bought or made with a round nosed end mill or burr). More likely it is flush riveted, fitting a couintersunk hole, and a hemispherical punch the same as the round headed ones of the same shank variety should be fine.

https://rivetsinstock.com/rivets/sol...um-rivets.html

Peening the rivet flat should work, providing that it isn't too hard and you don't aim for it to be too wide, or it isn't too hard. With too much widening or work-hardening it may crack. Sunderland flying-boats used to pop over-hard rivets and leak, but replacement softer ones were strong enough to secure the seam, and stayed intact. The boatbuilder will have taken care of the other danger of riveting, namely making the holes too close together or too close to the edge of the sheet, so that the sheet itself cracks.

The best sealant is probably zinc chromate paste, the greenish-yellow stuff you see in undercoat paint in aircraft manufacture. Also note that countersunk rivets are made with at least two angles, and the wrong one may weaken the joint or increase the chances of a slow leak through it.

[6bg6ga]

Can you use a product called Plastic Aluminum? Simply clean both the top and bottom and let dry and apply a bunch and let it dry.

[imashooter2]

A properly bucked rivet expands to fill the hole and seal. To do that, it must be driven from the head side with a bucking bar on the tail. You can use a two or three pound hammer for a bucking bar, but there really isn’t a substitute for an air hammer and set to drive it.

[leadman]

I used to repair semi trailers and have replaced rivets in my boat also. Easy job to do. Make sure the aluminum is flat, no burrs on either side. Place the rivet in the hole from the bottom. Have an assistant hold a heavy hammer on the head (#4 or more helps). I use an air chisel bit with a flat end to make it easier, put in your case you can hit it direct with a hammer. Peen it until the surface looks similar to the rest of your rivets. The first hit should be stout to make the shaft of the rivet expand in the hole.
Might want to inspect the rest of your rivets for any sign of movement and tighten them up also. The one opposite the missing one looks like there is dark gray around it which indicates it might be working in the hole.
My boat is a 1955 and I have tightened the rivets a couple of tomes and added another layer on the front of the keel. Used a piece of scrap aluminum semi truck cab from where I worked at the time.

[deetee]

All "pop-rivets" are "blind rivets", the term you are looking for is "closed-end rivet"

My thanks for the correction.

These rivets can be used with a normal rivet gun, and with a dab of sealer for added insurance should fix the problem for a reasonably long term.

Best,

Dan

[David2011]

For those that have never set rivets, they are easy and awesome. They completely fill a clean, properly fitting hole. No sealer is necessary but a pliable sealer won’t hurt anything. Air chisels and rivet guns look alike but rivet guns have a slower, more gentle impact and are much easier to control. For a one time repair you can make the buck with the rounded dimple and drive the rivet from the tail end with a hammer and flat ended steel rod. It takes two people to drive a rivet that way; best to not try to do it alone. If you just HAVE to try using an air chisel turn the pressure way down and drive a couple of rivets on scrap aluminum sheet first. I did mostly fabric repair but even fabric covered planes have some sheet aluminum of them so there were still rivets to set.

[quack1]

An update. Replaced the rivet yesterday, turned out I was over-thinking the process. Got a buddy to buck up with a 10lb sledge hammer head that I had a small dimple milled in to match the domed head of the rivet. I used a punch that I dimpled with the same ball end mill, to peen the head. Was easy to do, the rivet seems nice and tight. Since the local lake will be frozen for another month or two, wont be able to check for water tightness for some time. Or, if we get some warmer temps for a couple days, I'll be able to get the hose out in the back yard and run some water inside the boat to check my work.
Many thanks for all the responses and offers to mail some rivets.

[MaryB]

Boat: Break out another thousand! Always something to fix on them! I ran the local river a lot and hitting logs was common so the front took a beating! We often ran 15 miles(air miles) upriver to fish and came back around 3AM... so dodging deadheads in the dark... I had 2 yellow fog spotlights mounted down low under the bow so they didn't shine back in my face. Helped show the swirls to avoid... even with that you would tag stuff that was floating with the current and was just barely submerged...

So rivets needed attention often but I only tore one out... I had a local welding shop shape a piece of 1/4 inch aluminum plate finally that got bolted to the keel in front and wrapped back a foot on each side to take the abuse.

[shaper]

The dimple in the head of the rivet is there to identify the rivet. It is a AD 2117 with a universal head.

[Ballistics in Scotland]

Just a couple of very minor points. If it is a round-headed rivet, a round hole in the backing block, or a glued-on piece of hard plastic or hardwood if it is something valuable like a sledgehammer, will save you putting a flat on the head. If it is countersunk a countersunk socket screw Allen or torx, like those just over halfway down this page, would provide a temporary replacement you could safely allow to become less temporary than you are. An acorn nut would avoid snagging things especially part of your person, on the inside. Keeping a few in the boat, just in case, would be better than chewing gum.

https://www.westfieldfasteners.co.uk/ScrewBolt_M.html

In the late 70s I worked, in a very unmartial capacity, on the Riyadh air force base, and there I knew what Japanese swordmaking enthusiasts call a Living National Treasure. He was a key man on maintaining the English Electric Lightning, a 1960s fighter which came very close to equalling the performance of anything modern, but did it by an abysmal duration and combat radius. But he had worked on Spitfires in the Battle of Britain, and afterwards married a German fighter controller - female, as was the popular prejudice in those days. I remember someone showing him his plastic model Spitfire, with visible and feelable rivet-heads. He was outraged, for you wouldn't have seen the sort of riveting he did.