Whats wrong with welding?

[WeldZilla]

Re: Whats wrong with welding?

Welding up your boat as I see in the pictures would be easy. the hardest part would be cleaning up the patch that is already there.
I picked up an 84' Starcraft 1600 for vitrtually nothing because someboady pulled it across 2 states with the port side of the boat rubbing on the fender. By the time he got it here it had a 6 in X 1/2 inch hole rubbed through the side of the boat. Shops would touch it cuz it was too thin. I got it home took a 4 1/2 in. grinder with a stainless steel brush wheel to the outside to remove the paint around the hole and to the inside to remove the glued carpet fake grass crap on the inside. I did not acetone it or use anything else. I had no suitable piece to use to fill the hole or patch it at the time. I spent 45 minutes just spitting the hole shut. thats hitting the trigger on the spoolgun for about 1 second then letting off. when fininished I used a 60 grit flap disc to smooth it off inside and out. I touched up a couple places buff it off again and primed it. Never took the time to finish and paint it. I sold the boat. Problem solved no cracks no leaks no probs. Any welder worth his salt should be able to fix you up. The hard part is finding one. check the pic you will see where I shot some primer over the fix. I headed stright to the water to check for leaks. It was above the water line. So we test at home no leaks.

WeldZilla

For more on the machine and what I do at home look here.
http://forums.iboats.com/showthread.php?t=516113&p=3480587#post3480587

 

[sschefer]

Re: Whats wrong with welding?

Erik got it pretty close not to shabby for a amature welder.

Here's the deal... 5000 series Al is what you'll find used on welded aluminum boats. 6000 series is what you'll find on riveted alumium boats. You can easily MIG or TIG weld 5000 series aluminum because it is hammer hardened. 6000 series is a different story. It is heat treated and is highly weldable but will loose 50% of its strength in the heat affected zone (haz) of the weld. You cannot retemper it effectively so it becomes very soft in that area. Pre-heating it to about 200 degrees and then using a 75/25 argon helium mix will reduce the haz area significantly but you still must limit your welds to no more than 2" and then you have to let it cool. A lot of folks talk about stress cracks forming when welding. Truth is the stress cracks were already there and you just opened them up and made them visible when you welded it. This is because all Aluminum shrinks to some extent when welded. If the metal is in excellent condition you won't fracture it by welding. Riveted Aluminum boats almost always have stress fractures near the riveted area because they are constantly flexing. Read the manufactures brags about why rivets are better and the all say because the boat can flex and boats need to flex.. That's BS. What they should be saying is "We build our boats out of the thinnest and least expensive aluminum we can and we have to use rivets because we can't weld this thin currap"

Take it to a good welding shop and if it's riveted tell them it's 6000 series Al. If they say they can weld it then let them do it.

 

[lmuss53]

Re: Whats wrong with welding?

You could look for a welding outfit that has been in business for a few years near you, they have a welder that can do this for you. You can also find this guy at a local truck body buildiing place. My aluminum welder used to build and repair fuel and product tanks on big trucks, but now drives a truck. For welding he gets $20 an hour cash for him and his machine, and is worth twice that. His one rule is "Don't grind it, or try to fix it, with anything before you bring it to me. The stuff you put on it, or what you grind it with, makes it a SOB for me to weld."

Woodonglass' advice is pretty good though, some properly applied JB and a little TLC would have it looking good and it will last.

I plan to patch all the holes in my gunwales with an aluminum specific epoxy compound I got from the Chevy dealer to patch a crack in a pickup transfer case. It looks and acts a whole lot like JB Weld and I still have a lot of it left from the TC repair which has held up for about 10 years now.

If I find a below the waterline issue with my boat I will probably take it to the welder for his opinion.

 

[5150abf]

Re: Whats wrong with welding?

Welding can be the best solution or it can cause more problems, looking at your pics it is going to pretty hard to weld on your boat because the original owner used the JB weld or what ever it was, that needs to be removed completely which means sanding which means the metal is going to be even thinner than it is now and harder to weld so instead of a small hole you will have a giant nasty weld there.

Welding on older boats is a real pain because you can never get the metal really clean, your dent is right on a seam, I would use a dolly or backer and tap it out then check if it is leaking, you aren't going to want to fill that big of a hole with weld.

So yes it can be welded if you find the right guy to do it or you can go with the wrong guy and have it worse than it is now but it is going to cost $50-$100 so I would just clean up the old repair and redo it with JB, if the dent really bothers you fill it with JB too and sand it down and then paint it, it will look good and won't leak and you won't risk your boat to a bad weld job.

To qualify my answer I am a master level TIG welder with 23 years experience and I am currently the supervisor of the tube line at Bennington marine, I could fix this but I don't know that I would trust Bobs Welding to do it.

When I painted my boat I filled all the holes in the transom with JB Weld and sanded them down so it is a good cheap option that works.

 

[Bondo]

Re: Whats wrong with welding?

September 29th, 2010, 09:00 PM

Ayuh,.... :facepalm: