Welding old Aluminum

[songmanscott]

Hey - anyone have issues welding old aluminum? I plan on having a bench seat made and am wondering if that is a good idea...

1961 boat

Thanks

 

[LippCJ7]

Re: Welding old Aluminum

Doesn't matter, only thing you need to worry about is the thickness and having clean material prior to welding. Aluminum does attract corrosion, clean it up and weld, corrosion will only add impurities to your weld and may play with your bead.

 

[kfa4303]

Re: Welding old Aluminum

Hi songman. Welcome to iboats. As Lipp stated, the thickness of the aluminum is going to be the main factor. Thankfully, older boats like yours and mine tend to have rather thick hull compared to modern boats. As long as the area is prepped and welded properly it should work just fine. The trick is finding a good aluminum welder. It's a bit of a niche market and finding the right guy can be tricky. I would ask around town for starters. However, you may want to consider using aluminum angle and rivets to build your bench. It would be plenty strong, you can get materials at Lowes/HD and it's DIY which means you can take your time and experiment to find the best config./layout. There are tons of links here in restoration forums of folks using the method above with great results. Best of all, if you buy the bits and do the work yourself, you can save $ on the welder. Any pics of the boat itself? Lots of vintage boat buys here. I have an old '59 (I think) aluminum Arkansas Traveler.

 

[Mi duckdown]

Re: Welding old Aluminum

songman needs to show Pics of what he wants to DO.

 

[5150abf]

Re: Welding old Aluminum

Just make sure the metal is clean before you start and you should be fine but you need to clean all the oxidation off.


I would get a Scotch Brite pad and use that and the key to thin aluminum is to use a really low heat and you absolutely want to TIG weld this, I would never try to MIG anything that thin.

In the end aluminum is aluminum, as long as it is clean it should weld fine.

Also make sure you have a competent welder, TIG is hard to do so maybe ask to see some of your guys work before he starts on your boat.

 

[spdracr39]

Re: Welding old Aluminum

And make sure you are using the proper alloys. Some are harder to weld than others.

 

[gm280]

Re: Welding old Aluminum

When it comes to welding an aluminum boat, the first thing you need to understand is being a boat, and an older one at that, it was subject to oil from any outboard engine either installed on it or around it during those years. And being how aluminum is porest (spelling ?), oil did collect in those pores. So you absolutely have to remove that oil from the pores to be able to weld it. Otherwise as it heats it will pop from the oil and cause a suspect weld joint...

 

[dingbat]

Re: Welding old Aluminum

Got to laugh about thickness being an issue. Only an issue if you’re not experienced.

To clean, use an aluminum weld cleaner followed with a good scrubbing with a stainless steel “tooth brush”. You need something harder than the aluminum itself, thus stainless steel
Using things like a scotch brite pad will contaminate the surface by embedding small particles of the material in the surface of the aluminum.

Aluminum is not aluminum. There are over 300 different alloys in use today, nine of which are certified for marine use. Most are considerably different from the alloys used in the 60’s. Marine alloys of today have a much higher magnesium contest to combat the corrosion problems seen in the pasts and thus must be handled differently than in the past. The most likely alloys used in the manufacturer of your boat are 5083, 5086, and 5456. Use a 5356 filler rod for these alloys.

 

[jvanhees]

Re: Welding old Aluminum

Just make sure the metal is clean before you start and you should be fine but you need to clean all the oxidation off.


I would get a Scotch Brite pad and use that and the key to thin aluminum is to use a really low heat and you absolutely want to TIG weld this, I would never try to MIG anything that thin.

In the end aluminum is aluminum, as long as it is clean it should weld fine.

Also make sure you have a competent welder, TIG is hard to do so maybe ask to see some of your guys work before he starts on your boat.

Got to laugh about thickness being an issue. Only an issue if you?re not experienced.

To clean, use an aluminum weld cleaner followed with a good scrubbing with a stainless steel ?tooth brush?. You need something harder than the aluminum itself, thus stainless steel
Using things like a scotch brite pad will contaminate the surface by embedding small particles of the material in the surface of the aluminum.

Aluminum is not aluminum. There are over 300 different alloys in use today, nine of which are certified for marine use. Most are considerably different from the alloys used in the 60?s. Marine alloys of today have a much higher magnesium contest to combat the corrosion problems seen in the pasts and thus must be handled differently than in the past. The most likely alloys used in the manufacturer of your boat are 5083, 5086, and 5456. Use a 5356 filler rod for these alloys.

2 contrasting points of views....interesting.

All I have been told is to make sure you have a welder who knows his chit.

 

[Georgesalmon]

Re: Welding old Aluminum

Surprised that 5052 isn't mentioned. Though sometimes called aircraft grade I do know several AL boat manufacturers that have used 5052 for like 30+ years. AL does age harden some but can still be welded very well.