Rivited vs. welded

[ober51]

Man, you guys are way over my head. I like both, just don't want either to leak if I buy it.

 

[ben2go]

Then I will give my preference.Welded because flex in a riveted hull makes me nervous at times.

 

[CarlF]

Dont worry about riveted vs. welded.
Find a hull you like and can afford and buy it!

 

[sparkbr]

Dont worry about riveted vs. welded.
Find a hull you like and can afford and buy it!

I agree... And on that note, welded boats end to hold their value a little better than a riveted boat. Just something to keep in mind for resale down the line, as well as initial cost.

 

[Bugpac]

The problem with Mig's and aluminum is that the welds have porosity...

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.

and they also don't penetrate anywhere near like a tig.

That is an apples to oranges comparison. Depending on the amperage of the welding machine, many MIGs can outdo the equivalent TIGs. You are right on the TIG getting better weld from the start, whereas the MIG, on a cold start, will take a few seconds to warm a thick piece of metal enough for a good weld. But, that can be solved by preheating the area you are going to start the bead at with a mapp or oxy-acetylene torch, and the initial penetration will be close to the same.

If you got to chip a Mig weld you better keep googling... Back chipping is done when welding 2 sides of a large part, that are done in multiple passes, You back chip the root of the opposing side on a Butt weld, Or as your referring to it, you back chip a stick weld to remove scale... Mig welds create large heat affected zones, with alloys, Tig will create less heat affected zone, Heat affected zones are where cracks appear.. Not all aluminum is created equal as well... choosing the right material for the job is the first step, Boat manufactures don't tig there boats for cost reasons only, do some research and I am certain you will find this out... Mig weld serves the boating industry fine, but to say a mig has better weld quality than a tig only means you aren't all that good at Google... No matter how much you preheat the part, A mig weld always has a cold start.

 

[willfishforfood]

I've been following this and welding for 25+ years and I can weld almost any thing and own a rivited boat because it was cheaper.
16' rivited in 2000 was $3200 and welded was 5500 to 6000 for bare hull.
I like tig welding but would die if I had to weld up a complete hull and for mig if the gass is set right and you move the gun right it will look like a row of dimes on there side, too much gass makes the weld black and with too much carbon weaker . My boat is rivited and run a 50hp Yamaha and have had the whole boat out of the water more time than I should have but hey it can be fun.
Wife didn't think so. and still leak free. Now I do skinny water with the jetpump.
Here in the north west there is tons of welded boat but you won't see many over 25 years and that haven't been rewelded.
Aluminum gets harder with age and rivited boat are made from 5051 that is bendable and welded are made from 6061 and will crack if it is bent to a 90deg

 

[Zum]

My boats welded...pretty sure it's 5052.
Anyways...buy what you like,they will all do you fine,if not abused.