Brazing L to aluminum boat side

[Goaterson]

I just bought my first row boat to customize. I've seen videos of people attaching aluminum L to a bar of aluminum using brazing rods and a torch resulting a very strong bond. My question is could you attach aluminum L to the inside parameter of the boat using brazing rods for a casting deck? I can't find any threads or videos of someone doing this so I'm guessing it doesn't work. Has anyone tried this?

 

[GTS225]

I just bought my first row boat to customize. I've seen videos of people attaching aluminum L to a bar of aluminum using brazing rods and a torch resulting a very strong bond. My question is could you attach aluminum L to the inside parameter of the boat using brazing rods for a casting deck? I can't find any threads or videos of someone doing this so I'm guessing it doesn't work. Has anyone tried this?

I don't see how you could have seen what you described. Brazing involves brass rod and iron-based metals, and includes temperatures that will melt aluminum.
What you may have seen is the use of those aluminum/zinc "welding" rods that can be used to attach aluminum to aluminum, and the metals prep involves brushing both with CLEAN stainless brushes. Youi can weld aluminum to aluminum with a MIG welder that's outfitted with a spool gun.

I tell you this to prevent you from trying to "braze", in the classical sense, and end up with a big melted hole where you start to heat up the hull.

Roger

 

[Goaterson]

I don't see how you could have seen what you described. Brazing involves brass rod and iron-based metals, and includes temperatures that will melt aluminum.
What you may have seen is the use of those aluminum/zinc "welding" rods that can be used to attach aluminum to aluminum, and the metals prep involves brushing both with CLEAN stainless brushes. Youi can weld aluminum to aluminum with a MIG welder that's outfitted with a spool gun.

I tell you this to prevent you from trying to "braze", in the classical sense, and end up with a big melted hole where you start to heat up the hull.

Roger

Thanks for the recommendation. Here's a link to the brazing video I saw.

 

[airshot]

I would trust SS screws and nuts over that stuff !! With todays variety of sealants, no excuse for leaks. Unless your a pro aluminum welder, it won't look good.....

 

[Crazyboat]

I admittedly know very little about welding, but that looks more like soldering then a weld to me. Please correct me if I'm wrong.

 

[airshot]

I admittedly know very little about welding, but that looks more like soldering then a weld to me. Please correct me if I'm wrong.

The pictures always make it look easy, from what I have witnessed, it isn't very strong.

 

[drxfish]

A local aluminum welder did a video with a guide talking about how difficult it is to weld aluminum boats correctly. The issue is getting the surfaces properly clean to get the temperature right and make everything work. I bought some of those aluminum welding rods with the intention of using it on my old jon. It did not work like you see on videos. The heat dissipates unless you have the proper torch. Then you have the whole impurities issue.

 

[thill]

You could try the aluminum brazing rods, but the alloy of boats does NOT like those rods much.

Personally, I would drill and use solid rivets or well-sealed stainless bolts to attach.

You could certainly Aluma Braze your components together before installation. It works well with the angle stock like you see in that video. I've used it to add flat plates to the ends of aluminum angle, to make it easier to rivet/bolt into place. That stuff does have it's uses.

 

[mirrocraft16]

Those aluminum welding rods have been around for decades, they are a form of brazing or solder and can be very strong if done right. They do not do well on certain alloys and that includes most aluminum boats. They do best on common extruded aluminum and some cast aluminum.
The first time I ran into these was at a car swap meet in the 80's, they were cheap so i tried a pack.
After doing not much more than experimenting with them a bit I tossed them in the tool box and forgot about them. A few years later someone gave me a set of full length running boards for my truck but they were too long.
I was able to use those rods to cut and make a set of cab-only running boards for my truck with them by moving the brackets and welding in the cut rear edges on both sides. They lasted the life of that truck, about 30 or so years, and were on it when I sold it 8 years ago.
The key is first to make sure the aluminum is spot clean. You have to use a stainless brush to get through the natural corrosion layer that protects all aluminum and you have to make sure that the surrounding areas are clean as well so it don't bleed into the weld when its hot.
Using it is more like sweating pipes or hot glue. You have to find the right temp then apply the welding rod. Too hot, and the aluminum will melt or blow right through. You DO NOT WANT TO MELT THE METAL BEING WELDED. doing so will prevent the weld from sticking and it will likely blow through or sag making it useless regardless.
You need clean metal and just enough heat so that the rod melts when it touches the metal being welded. Getting it too hot and it runs like water.