Welding aluminum frame?

[chriscowles]

While working on wiring today I took out the lauan panels in an outside locker and discovered water damage. The right front corner of the floor is separated from the nose cap and allowing water in. I assume splashes in off the road.

I haven't explored the problem much because I had to finish the other project. One thing I did note is that the 1" aluminum tubing frame is broken at the joint attaching the face frame onto the side wall at the bottom of the wall. It's a clean break at the joint.

How do I engage someone to repair the broken weld? It's easily accessible but is snug against the floor and walls.

I think it will be pretty easy to seal up the hole after the weld is repaired.

[Aussieguy]

talk to a local welding shop

if you can do the prep work they can weld it in a few minutes

[chriscowles]

Originally Posted by Aussieguy

talk to a local welding shop

if you can do the prep work they can weld it in a few minutes

Unfortunately, this may require two trips. One for them to see the job and give me prep instructions and another to do the actual job after I've prepped it.

[chriscowles]

Originally Posted by chriscowles

Unfortunately, this may require two trips. One for them to see the job and give me prep instructions and another to do the actual job after I've prepped it.

Duh. I can eliminate one trip by sending pictures. It should be evident what they have to do. I'll post those pictures here to see if others judge them adequate.

[MGD1961]

Originally Posted by chriscowles

Unfortunately, this may require two trips. One for them to see the job and give me prep instructions and another to do the actual job after I've prepped it.

Don’t know about your area but we have a bunch of mobile welding guys around here. Let them come to you.

[ppine]

Welding aluminum is not that easy. It is a specialty. Boat shops are good at it.
Consider bolting it back together with a sleeve.

[chriscowles]

Originally Posted by ppine

Welding aluminum is not that easy. It is a specialty. Boat shops are good at it.
Consider bolting it back together with a sleeve.

I thought as much. (I.e., it's a specialty.)

Unfortunately, it's in a corner. Also, the back sides are securely attached to the floor and the outside wall. There's no way for me to get anything around it.

I may end up reinforcing the corner with 90 degree brackets attached with pop-rivets. The bracket material will have to be aluminum.

I'll post pictures later today when I have a chance to be out there again.

[NMWildcat]

We use a TIG to weld aluminum frequently. Most certified welders have no problem identifying what type of aluminum it is and how best to weld it.
One problem with aluminum is that it transfers heat readily. So if you can't clear the area to be welded, it will be hard to control the heat transfer to material you want to keep cool.
Let us know what the welders you contact come up with.

[MGD1961]

Originally Posted by chriscowles

I thought as much. (I.e., it's a specialty.)

Unfortunately, it's in a corner. Also, the back sides are securely attached to the floor and the outside wall. There's no way for me to get anything around it.

I may end up reinforcing the corner with 90 degree brackets attached with pop-rivets. The bracket material will have to be aluminum.

I'll post pictures later today when I have a chance to be out there again.

Why would the material have to be aluminum? It’s a dry location I assume so use steel.

Use self tapping screws and you could even glue it with something like Plexis MA310.

These are alternative suggestions. I would still call a welder first.

[Tireman9]

Yes contact welder first. If you paint or glue or attach other parts first you may make the repaid more difficult or impossible as cleanliness of the aluminum is mandatory for TIG welding. Attaching steel to Aluminum can cause corrosion. Yes, aluminum and stainless steel can and do corrode when put together. The two differing metals set up a galvanic couple.

[ppine]

Sheet metal screws will work. Forget pop rivets. Welding in a tight area burns up everything.

[MGD1961]

Originally Posted by Tireman9

Yes contact welder first. If you paint or glue or attach other parts first you may make the repaid more difficult or impossible as cleanliness of the aluminum is mandatory for TIG welding. Attaching steel to Aluminum can cause corrosion. Yes, aluminum and stainless steel can and do corrode when put together. The two differing metals set up a galvanic couple.

There is no galvanic action without an electrolyte. AKA water. Trust me. I’m certified in galvanic corrosion testing. You are never going to have an issue with dissimilar metals unless it is constantly wet or used as an electrical conductor

[chriscowles]

Originally Posted by MGD1961

There is no galvanic action without an electrolyte. AKA water. Trust me. I’m certified in galvanic corrosion testing. You are never going to have an issue with dissimilar metals unless it is constantly wet or used as an electrical conductor

Does humidity count? I live in Florida.

[MGD1961]

Originally Posted by chriscowles

Does humidity count? I live in Florida.

Not to any extent short of condensation forming.

All of this considered how about using heavy angle aluminum with stainless fasteners and if you are concerned coat the fasteners with Teflon gel.

[chriscowles]

I'm thinking of buying a piece of 1" wide aluminum. I'll cut one piece about 6" long and bend it at an obtuse angle matching that of the frame.

I already have some self-drilling screws intended for aluminum. I bought them from McMaster-Carr to attach solar panel brackets to the same aluminum tubing frame material. I'll drill holes in the angle bracket and use those holes to drill the screws into the frame.

The angle will lay on the upper surface of the front inside corner. I'll put another flat piece along the side facing towards the inside of the trailer. It will be mostly overlaying the side frame (parallel to the side of the trailer) and will overlap the face frame by the width of the metal tube. The screws will be at a right angle to the direction of the tension on the joint so it should be pretty strong.

I'm camping right now so I can't disassemble the front locker to expose it. I'll do that this weekend so I can post pics and a diagram.

[chriscowles]

To close out this thread, I finally had a chance to assess the problem further. I conclude that the issue is not so much a broken weld as it is crappy construction.

There are two welds on separate member that are close together, as seen in the first picture below. The weld on the bottom corner is what I interpreted as broken. It may not have ever been welded correctly. If you look at it, I surmise that someone attempted to put in a spot weld. Whether they were successful or not, I do not know.

I am satisfied that the frame is secure. While the weld on the upper cross member is nothing more than two spot welds, it is intact and the front frame is secure. The bottom horizontal piece is firmly attached to the floor so, in combination with the spot welds that are intact, the walls and floor are secure.

I thought earlier that I saw a gap on front edge of the floor. I did not. There is evidence of water intrusion resulting in fungal growth and a small spot at the bottom of the front plywood. I cannot find a source, though, and the entire area is dry despite having had significant rain lately.

I'll inspect it again after driving in a rainstorm to see if wind pressure drives some water in. Until then, there's nothing for me to do.

larger view


lower weld


upper weld


fungal growth

[NJKris]

Regarding your leak, I hope you didn't get wet underbelly like I just discovered. I think the water came in the same area that your did. Insulation in underbelly was saturated, and it started smelling musty in the camper.

[chriscowles]

Originally Posted by NJKris

Regarding your leak, I hope you didn't get wet underbelly like I just discovered. I think the water came in the same area that your did. Insulation in underbelly was saturated, and it started smelling musty in the camper.

Evidence of the amount of water intrusion is unclear. There obviously was something but I can't tell how much or where it comes from. The soft spot in the front interior lauan wall plywood is only about 1" high by 4" wide, at the joint with the floor. The appearance of the fungus stuff suggests the soft spot would have been larger.

I'll explore more when I get to my base camp in Cades Cove in July. The underbelly of ours is different, anyway. We have a Coroplast sheet, as you do, but the insulation is limited to a heavy reflective fabric. There's nothing to absorb water. If anything was puddling it could only be very little in a dip in the Coroplast, and there's really nothing there to damage. If it was wide enough of a puddle to reach the sides, it would leak out along the edge.

[NJKris]

Oh, that's good about the insulation. I did note that once the water got in there, there was no way for it to get out. I became aware of this after investigating how to repair three big holes a groundhog had chewed through the membrane in that section. She must have been attracted to the musty stinky wet insulation smell for some reason.

[Tireman9]

Originally Posted by chriscowles

To close out this thread, I finally had a chance to assess the problem further. I conclude that the issue is not so much a broken weld as it is crappy construction.

There are two welds on separate member that are close together, as seen in the first picture below. The weld on the bottom corner is what I interpreted as broken. It may not have ever been welded correctly. If you look at it, I surmise that someone attempted to put in a spot weld. Whether they were successful or not, I do not know.

I am satisfied that the frame is secure. While the weld on the upper cross member is nothing more than two spot welds, it is intact and the front frame is secure. The bottom horizontal piece is firmly attached to the floor so, in combination with the spot welds that are intact, the walls and floor are secure.

I thought earlier that I saw a gap on front edge of the floor. I did not. There is evidence of water intrusion resulting in fungal growth and a small spot at the bottom of the front plywood. I cannot find a source, though, and the entire area is dry despite having had significant rain lately.

I'll inspect it again after driving in a rainstorm to see if wind pressure drives some water in. Until then, there's nothing for me to do.

larger view
Attachment 301206

lower weld
Attachment 301207

upper weld
Attachment 301208

fungal growth
Attachment 301209

WHile I am not a "Certified Welder" I have taken a course at Lincoln Electric. The weld in #207 was not made correctly. Also I would consider most of these welds to be more like temporary "Tac welds" that structural welds.