Home Forums Hunting & Shooting Hunter's Campfire Aluminum Boats- Riveted or Welded?

There's welding, and then there's welding.

More importantly, there's Aluminum, and then there's Aluminum.

Aluminum alloys come in various grades. Some hard, some soft, some brittle, some ductile.

Just as an example, the first boat I bought to take the G-kids fishing in was a little 14 foot Shasta with an 18 hp Merc. When I started drilling holes in the hull to mount rod holders and such, the Aluminum cut like butter. When we took the boat out on Brownlee Res and the wind came up in the morning at sunrise, the floor would visibly flex with impact of every wave. Within a half dozen outings, the floor had cracked at each flex point and water was coming in.

Brownlee is the first dam at the head of Hells Canyon. The lake averages maybe 1/4 to 1/2 mile across. But it is about 40 miles long. Each morning at Sunrise the breeze kicks up and produces six to eight inch chop.

We fished from the Shasta for two years, and periodically hit the switch on the bilge pump to remove the water.

Then I bought a 16 foot Lund hull. I built a console into it and put my little Merc 18 on it. Drilling holes in the Lund was night and day difference from the Shasta. The wall thickness was very similar, but the Aluminum in the Lund was much harder.

In the same lake, under the same conditions, there was no flex in the Lund hull.

You will find the same to be true of welded boats. Some are constructed of superior, expensive Aluminum alloys. Some are made of less expensive alloys, and are more prone to stress cracks or heat damage along weld lines.

Most of the better built boats will tout their alloys in their advertising copy. It pays to become familiar with the alloys, or at least know how examples of the boat model has performed for others before investing a large sum of hard earned money.

In 24 years of ocean service, crabbing in December also, my old riveted Starcraft has never had a loose rivet. The Pacific Coast north of Cape Mendocino and south of Coos Head is not very pacific. The access to open ocean is over bars. The Rogue River bar at Gold Beach is legendary. The Starcrafts are the proven boats, I believe of the Walleye fisherman on the Great Lakes which I believe blows up as steep and quick as any water in North America.
The technology of tig welding has improved over the years, but I am not aware of any welded aircraft, I personally have ridden tens of thousands of miles in Alaska and the Aleutians in my company's DC-3, it was 50 years old when they bought it.

Finally. Someone gets it. Tip of the hat sir...

Wrong

The reason for a riveted hull over a welded comes down to weight. If you want or need a light boat you go with a riveted hull, if weight isn't a factor and you want less worries you go welded. Edit: Second reason for a lot of people is price. A riveted hull is cheaper in general terms.

Aircraft structures are not welded because of load distribution. A weld the load is all in one place directly on the weld. A riveted (to include all fastener types) structure transfers the load to the entire structure. Seams are overlapped and in most cases terminate at a Bulkhead, Longerons, strings, stiffeners, and other heavy aircraft fittings. Show me a cargo ship that isn't welded!

All fasteners loosen over time from both load and temperature changes. Boat hull rivets absolutely loosen and leak!

Airplanes, and semi trailers are riveted.

You got that 1/2 right, does that make yu 1/2 wrong?

It is 100% right. I could have given more details as to other reasons fasteners are used over welds but really no need to. But yes I did leave out that welds add a lot of weight to the aircraft. A normal rivet pitch of AD rivets weights a fraction of a weld. Even Hi-Loks weight less than a weld would. Fasteners are removable and replaceable. Though most do not properly replace working rivets. Some will try to buck them more, others will remove and replace with the same nominal size. When they should be going one over, so a repair rivet is the proper way to go about it. Unless of course the hole is a full size or close enough to step up to the next nominal. Another factor is in some places shear or Tension fasteners are required. But that is getting way into things.

Bottom line is a welded Aluminum Hull is a better route unless weight is a deciding factor.