bad weld joins on a gifted shed build, do I/how do I broach this with the builder?

[1a1a]

Putting this in friends/friendship because the builder in question is my dad’s friend and he worked for free because he wanted to help my dad out. I think this is a pretty massive favour and no small deal and even with this one problem I don’t want to knock the work that’s been done, if there was no friend/favour aspect then I could just tell them the work isn’t up to scratch and request a re do.
 

My dad made friends with a Chinese builder and he’s been teaching him English. 
 

The builder is super helpful, he helped my dad help me move and then when I ended up in a house with no shed, he offered to build one free of charge (just the cost of parts and a cheap day rate for his welder friend because he can design the structure but he doesn’t know how to weld). 
 

Over the last week this neat little structure has manifest on my patio all made from galvanised steel. On the third day I happened to look at one of the weld joins and it looked very odd, blotchy and black. I’ve seen weld joins before they don’t normally look like that. Tried to be blissfully ignorant but there’s too much at stake if this structure fails (all of my work tools are gonna go in there). Found a friend who knows welding and got him to have a look. He said the welds will corrode over time because they didn’t clean the galv and the metal is contaminated and that they wouldn’t meet Australian standards.

So the almost free shed is going to need some strategic reinforcement before I can feel comfortable using it, which I’d rather get someone who knows how to weld to do, I don’t want to ask these two guys to come back and do more work, I already feel like they’ve done me an amazingly awesome favour (plus, clearly evident any further welding should be done by someone who knows how to satisfy Aus standards). I’m happy to take it from here and reinforce it. But I can’t believe anyone would go to the effort of building a shed for free/token pay and intentionally do weld joins so bad the structural integrity of the building is in question. Like they worked hard, in awful hot humid weather, sometimes redoing parts if they thought of a way to do them better. The bad weld joins make the whole build potentially a failure waiting to happen and a big waste of time and effort and I want them to not make that same mistake next time. 
 

Which brings me to the actual question, how do I, not a tradie, just a lay person, inform my dad’s friend (the foreman of the project if you will) that weld joins are questionable without offending him?

Plus a million points if you’re Chinese or familiar with Chinese culture and have a sense of how someone immersed in that culture would handle it. 

 

Edited February 2 by 1a1a

[Wiseman2]

1 hour ago, 1a1a said:

  I can’t believe anyone would go to the effort of building a shed for free/token pay and intentionally do weld joins so bad the structural integrity of the building is in question. 

So you believe the incompetence and wear and tear is intentional? 

Is this builder licensed? If not and since it was free/a favor, you'll have to do whatever repairs and re-enforcement at your own expense.

Or give the shed to your father and buy yourself one that is structurally sound.

[Jibralta]

If you're really worried about the welds talk to a licensed structural engineer, not a 'friend who knows welding.' An engineer will have expert knowledge about welded connections. For example, different types of welds (bead, fillet, groove, etc.) are appropriate for different conditions. Type of structure and loading paths also play a part in the evaluation. It's not just about blotchiness, which is common when a welder is still learning. What I'm saying is, depending on the structure, this may not be an issue at all.

[lostandhurt]

Just for reference I have been welding for over 40 years as a hobby fabricator and at work.  I am not a certified welder though.

  The outward appearance of the galvanizing being burned as the seam is welded will leave the appearance you mentioned but that does  not mean the weld is structurally unsound. I have welded galvanized pipe were I only ground back the galvanizing 5mm and it still burned from the heat and looked like you describe but was not a weak weld.  The size of the welds, penetration, type of welder that was used, filler rod used, flux core or shielded gas not to mention welder settings all affect the strength of the weld joint. I have seen aesthetically beautiful welds crack and fail so looks don't always mean anything.

  The welds should have been wire brushed and sprayed with a cold galvanizing spray paint for sure to make sure they do not rust and look nice for years to come.

If it were me before I said anything I would do a load test on the shed.  I am assuming it is smallish so stand at the corner outside and shake the heck out of it.  If it is solid then check all the welds for cracks or bending.  If it is wobbly and moves easily call your dad, I am sure he doesn't want you in a shed that is unsafe.

  I would be happy to take a look at some pics if you like just pm me.

  Lost    

[East4]

The Chinese New Year took place yesterday, the 1 February, it is one of the most important celebrations in their calendar.

Buy a small, but maningful gift, or bake a cake, or something, and ask the Chinese builder to meet for a short meeting to present him with the gift.

At the meeting kindly request an appointment with him and the welder to inspect the structure, citing as a reason that you were informed by the local administration that the shed structure needs certification. So before the certification, you need one final check by the welder and the builder.

As you came with a gift and a nice smile, the builder will not turn you down. Then, durig the inspection with the welder presentn you can point to the welding scar and ask question why it looks so bloaty and black. Hear what they have to say.

Most certainly, if indeed there is a mistake, it was not done on purpose by the builder. Given the very low daily rate that you paid to the welder and the hot weather, he might have been tempted to finish the work quickly and prioritised time, over quality. 

[tattoobunnie]

I'm Chinese. We're still celebrating Chinese New Year.  So bring him some oranges, and tell him and his family, Happy New Year!  Ask for the welder's info, and let him know you have concerns about the weld, and you'd appreciate him coming to take a look.  And in most cases, he'd probably fix it, or explain why it's okay.  It's that simple; just be honest.  

I used to teach welding when I was in college, so if you have a pic, that'll help too.

[1a1a]

I love love love the advice to bring a gift. 
 

And skip the favours from friends and go straight to licensed structural engineer. I wasn’t really sure who I could ask. 
 

I’ll share a couple of examples, first one is holding the supports for the floor in place, second one is the roof. Notice the addition of a bracket. 
 

I’ll give the shed a more vigorous shake and inspect the welds but my impression thus far is that it is pretty sturdy, just the floor has flex. 
 

The builders know about cold galv but there’s a language barrier and when they tried to buy some they got the wrong thing. I offered to clean and cold galv the joins this week. 

[1a1a]

Ok, I tried shaking it, that thing is as solid as a rock!

[lostandhurt]

I replied to your PM and the pics you sent me.

It looks like they used a mig welder with flux core wire to weld the joints.  This would be my choice as well since they are working outside in the wind and welding plated galvanized metal.  The black areas you see are slag from the shielding flux and the white areas are from the galvanized coating burning and converting to zinc oxide.  The slag can be removed with a chipping hammer and the zinc oxide can be easily removed with a wire brush.  All the cuts and welds need to be spray painted with cold galvanizing spray paint or grey paint to stop it from rusting and make it look way better.

  The welds are not pretty and could look way better but they look plenty strong to me and in some cases it looks like they went overboard with the welds.

Since you gave it the shake test and it didn't move or make popping sounds you should be good.

Ask your dad to pretty up the welds with some wire brushing and paint and your shed should be good to go.

  Lost

[boltnrun]

I used to work in a weld shop (not as a welder) and those welds look supremely ugly but will probably hold up.

Perhaps an actual welder can advise if a grinder to smooth out the welds would be appropriate or would that possibly weaken the welds?