That is a good point, kinda makes ya wonder don't it?smoody said:Airplanes are riveted. makes me wonder the theory behind welded be superior.
You must own or have looked at a Lund. They push that point a bit.smoody said:Airplanes are riveted. makes me wonder the theory behind welded be superior.
I used to think that this was hokus pokus, provided you rinsed the boat after each use. While the salt isn't going to just eat away at rivets, on my most recent boat project purchase, I did find why riveted boats and salt water don't mix. Obviously for a boat to be riveted, two layers of metal have to overlap. Usually, there is a sealer in between the two, but sometimes that works free, or there is a void or something. Anyway, this void will get a little water trapped inside, and start to corrode both layers from the inside out. By the time you see the corrosion, it has made its way through the whole thickness of the metal, and has often spread a couple inches along the seam.If you abuse a boat, maybe welded is worth it. Maybe a little better in saltwater, some foks think so.
Basically, one is not better than the other, but both have their advantages. If one was supreme to the other, don'tcha think we would only be seeing those?
Sorry, I wasn't trying to contradict you with my above statement. It apparently came out that way though.smoody said:Basically, one is not better than the other, but both have their advantages. If one was supreme to the other, don'tcha think we would only be seeing those?
I agree. My statement was to question the claim of a welded jon to be "tougher" when in reality the opposite is likely true, is welded better for "floating", again maybe but a leaky rivet is easier to repair on the water vs. a broken weld. The aircraft engineers use rivets vs. welds because the aircraft must "give" and "flex" when hit by turbulence and to withstand the force of landing the plane. With that said I guess we can't say rivets are stronger as obviously they are used when "flex" is needed resulting is a stronger bond when faced with certain conditions.
I'm calling BS on that. While TIG is ideal for smaller gauge metals, and "pretty" welds, on the thickness of metal that most welded boats are made of, the MIG is going to make a more structurally sound weld. Not to mention the cost. If TIG were the industry standard for aluminum boats, my estimate is that we would not see 90% of the manufactures we do.TrackerTom said:The funny thing to me about welded boats is that they are done with a mig and made with fairly "dirty" aluminum. If you really wanted it to be strong welds, the welds would be tig welded.
Sorry, I wasn't trying to contradict you with my above statement. It apparently came out that way though.
bassboy1 said:Sorry, I wasn't trying to contradict you with my above statement. It apparently came out that way though.smoody said:Basically, one is not better than the other, but both have their advantages. If one was supreme to the other, don'tcha think we would only be seeing those?
I agree. My statement was to question the claim of a welded jon to be "tougher" when in reality the opposite is likely true, is welded better for "floating", again maybe but a leaky rivet is easier to repair on the water vs. a broken weld. The aircraft engineers use rivets vs. welds because the aircraft must "give" and "flex" when hit by turbulence and to withstand the force of landing the plane. With that said I guess we can't say rivets are stronger as obviously they are used when "flex" is needed resulting is a stronger bond when faced with certain conditions.
Anyway, you are exactly right on the flex issue. Riveted boats are designed to have flex, as not having any give in a boat made of thin material would be disastrous. The big welded plate alloy boats are made to have no give. In fact, recently I was reading on a plate alloy boat forum about a guy whose engine fell off. The motor, an under warranty Honda 225, broke at the mount, and fell off. Honda techs scratched their heads at this issue for the longest time, and it finally took calculations from a structural engineer to solve the problem. The issue was that the owner was running the boat through 4 foot swells, then hit one larger one at a bad angle, knocking the 26 ft boat around hard. Most non alloy boats would have enough give to absorb some of that energy, but the Black Lab alloy boat had no give, and thus transferred all that energy to the motor, busting up the casting and a couple 12mm bolts.
Here is the whole story, if you want to read it.
https://www.aluminumalloyboats.com/viewtopic.php?f=4&t=1700
I'm calling BS on that. While TIG is ideal for smaller gauge metals, and "pretty" welds, on the thickness of metal that most welded boats are made of, the MIG is going to make a more structurally sound weld. Not to mention the cost. If TIG were the industry standard for aluminum boats, my estimate is that we would not see 90% of the manufactures we do.TrackerTom said:The funny thing to me about welded boats is that they are done with a mig and made with fairly "dirty" aluminum. If you really wanted it to be strong welds, the welds would be tig welded.
Nevillizer said:Not an expert on any of these issues; mig; tig; welded or riveted. I think it boils down to the craftmenship of the boat, what it is going to be used for and the care taken by the operator. Just my thoughts.
Most of the time, that porosity is in the top layer of weld. A process called back chipping eliminates that. Basically, when you run a bead, you go back with a carbide blade, either on a die grinder or even a standard skil saw, and chip off the top layer of weld. Then, run another bead, and keep chipping layers off until you get to where you need to be. I guarantee none of the big name welded tinny companies do it, but you will find on some of the bigger fishing boats made by custom companies up in the Pacific Northwest that this is a somewhat common practice.TrackerTom said:The problem with Mig's and aluminum is that the welds have porosity...
and they also don't penetrate anywhere near like a tig.
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