Frustrating pontoon repair

[CincyFlyer]

The PROPER repair would be to weld it.
TIG first choice and MIG if TIG is not available.
Rivets, glues or sealers are for emergency repairs or for amateurs.
Welding challenges are part of it and experience is learned.
If you are lucky there is an old Fart around to show you tricks.

In the past I would have agreed with you, but with a fairly large area that may have fatigue cracks, I'd likely either cut the entire area out and weld it, or go with a more flexible repair that won't introduce more stresses. Rivets, glues, and sealers still hold most flying machines together; they work quite well.

 

[TractorGuy]

In my VERY limited experience with welding aluminum the first thing I notice in your pictures is the patch area wasn't cleaned beyond the welded area. You don't have a chance in **** of getting a good weld unless the area is cleaned past the area of repair and you know your filler material is compatible with the material being welded. My first and best experience welding aluminum with a tig involved new material and compatible filler rod purchased from a source that knew what to supply me with. Some of my worst results involved me using the same filler rod on higher grade surplus aluminum and unknown grade aluminum.

Either way the darkness at the edge of the patch indicates they did a sloppy cleaning job before they started and haven't a clue how to weld aluminum.

 

[The Fred]

This is the PERFECT time to talk your wife into letting you buy a new boat!

Go for it buddy!

 

[ruffdog]

Was the plug removed before welding? Air movement at the crack site would affect the shield gas and thus the weld. For smaller tanks, I have pumped in Argon to help the weld process. Most pontoons are a .080" material and should be plenty easy with a 1/16" tungsten. Before welding, etch with the arc and brush with a fine stainless brush. Weld out in the hot sun as it will help pre-heat the aluminum.

 

[kevinwak]

This is the PERFECT time to talk your wife into letting you buy a new boat!

Go for it buddy!

Would love to buy a new one, but there are tons of things on the “to buy” list.

 

[kevinwak]

Was the plug removed before welding? Air movement at the crack site would affect the shield gas and thus the weld. For smaller tanks, I have pumped in Argon to help the weld process. Most pontoons are a .080" material and should be plenty easy with a 1/16" tungsten. Before welding, etch with the arc and brush with a fine stainless brush. Weld out in the hot sun as it will help pre-heat the aluminum.

They did not remove the plug, even though I told them to. They didn’t believe that it would build pressure. . Then they questioned why I added so much air into it when I parked it in the sun. I didn’t add air, heat builds pressure.

 

[PILOON]

First thing that needs doing is to stop drill that crack.
Then whatever patch system used will work.
While welding seems the best I still believe a surface patch with 'POP rivets' or better still standard aircraft style brazier rivets and sealant is the proper way to go.
OK. so much for my 2 cents.

 

[dragoneggs]

First thing that needs doing is to stop drill that crack.
Then whatever patch system used will work.
While welding seems the best I still believe a surface patch with 'POP rivets' or better still standard aircraft style brazier rivets and sealant is the proper way to go.
OK. so much for my 2 cents.

As an aerospace engineer with a fair amount of experience in adhesive bonding to metals and composites... if done right, I am totally with you. I call them 'chicken rivets'.

 

[ruffdog]

They did not remove the plug, even though I told them to. They didn’t believe that it would build pressure. . Then they questioned why I added so much air into it when I parked it in the sun. I didn’t add air, heat builds pressure.

Yep...that is what I was thinking. Get someone with more experience.

 

[OkieDave]

Rivets and ProSeal (many aircraft fuel tanks are built this way). See VAF Forums - Search Results (or just go to Welcome to Doug Reeves' Van's Air Force Web Site and search for ProSeal). More than you ever wanted to know.