Welding standards

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Welding standards

Postby somsip » Fri Jul 10, 2015 9:39 am

I've got a build ongoing in the 'Your Building Story' thread, and I'm seeing work on the roof trusses that I'm really not sure is up to standard. We've got zinc galvanized metalwork going up, with confirmation that welds will be painted over with red lead once it's completed, but the welds themselves look rough to me. My only comparison is smooth, flowing welds on things like motorbike and bicycle frames, and I'm not really expecting them to look like that, but I'd appreciate any observations on these: whether they're safe, or whether they need to be re-done.

Thanks.

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Re: Welding standards

Postby olavhome » Fri Jul 10, 2015 10:19 am

Can understand you feel it look substandard. Ask them to do it more proper :evil:
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Re: Welding standards

Postby Roger Ramjet » Fri Jul 10, 2015 12:29 pm

To be absolutely blunt and honest the welds are crap. They don't have enough amperage or they have their earth clamp too far away, which is why the lazy welder left half a welding rod sticking up in the air in the second photo. He could have broken/worked it off but didn't bother. It's just an amateur lazy job.
And they can do running welds.... but to explain all that would take hours and then they would ignore you.
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Re: Welding standards

Postby somsip » Fri Jul 10, 2015 1:38 pm

Thanks for the replies, but looks like I've jumped the gun on this one. I've had a few stressful days with driving down to Malaysia for a visa and then flying up to Bangkok for a new passport, and I'm just a bit edgy still. Too much caffeine and not enough sleep...

So we went to see the builder and asked about the roof. Basically we asked if it was finished how it is and his immediately reply was that it wasn't finished and all the welds needed to be tidied up and then painted with red lead. The decision was made to cut the bars with the welding gun (hence the ragged edges) and spot weld them into place, with the intention of putting proper edges on with flush welds later. It could be argued whether this was the right approach for him to take, but the end result is what matters to me. And now I know that this is not the end result, and he knows what I expect on this.

This was volunteered information rather than something that sounded like an excuse or BS, and with how the builder has been so far with everything else it doesn't concern me unduly any more. I will be doing a close inspection of all of this before okaying the work, so I'll just let him get on with it for now.

That's it. Thanks for reassuring me I can spot a crap bit of welding when I see it :)
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Re: Welding standards

Postby MGV12 » Fri Jul 10, 2015 1:43 pm

Lazy indeed ... they couldn't even be bothered to mark the lengths/angles correctly and then use the chop saw ... just burn it through with the stick.

There is so much wrong with that job I wouldn't consider those who did it are capable of putting it right. Tearing it down and starting again is probably too extreme to consider but if the rest is the same as the pics it will take as long [maybe longer] to turn that dogs breakfast into a structurally sound one that will support your tiles adequately. You mentioned originally about using the architect as project manager ... if that happened he need a good kick up the butt ... as does the contractor.

Your post of June 7 suggests you paid them for the roof a good month before it was erected ... if so it may be a salutary lesson. Never, ever, get ahead of the game with payments.

somsip wrote:This marks the end of stage 2, so the money for the roof was paid on Friday.


Hope you can get it sorted without blood being shed :( if 'they' do propose [convincingly] that it can be corrected a lot of attention will also need to be given to ensuring the 'repairs' are as well protected as the galvanised steel you paid extra for. I read that you are buying your tiles from SCG ... suggest it would be a good investment to pay them a visit and employ someone who knows what they are doing to oversee the corrections. Other members have reported that they do have some knowledgeable people ... albeit many/most/all are no doubt subcontractors.

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Re: Welding standards

Postby somsip » Fri Jul 10, 2015 3:42 pm

MGV12 wrote:There is so much wrong with that job I wouldn't consider those who did it are capable of putting it right. Tearing it down and starting again is probably too extreme to consider but if the rest is the same as the pics it will take as long [maybe longer] to turn that dogs breakfast into a structurally sound one that will support your tiles adequately.


Sobering words. Earlier I'd accepted that this could be finished off in a way that would be to standard, but if each truss has to be cut, and a new angle welded onto it to provide a flush weld to the main supports, I can see how much time this will take and that that end result will not be as strong as if it had been done right in the first place.

Tearing it down and starting again is not too extreme. I'd be happy making that decision if the proposal to fix it is going to be unworkable or unsafe. It's maybe 8 days work and a bit of steel, most of which should be salvagable. The project manager is saying that this was a sub-contractor, but the responsibility ends with the builder on this, whether his team have done the work, or whether it's been farmed out.

We have a meeting on site with the architect, project manager and builder at 9am tomorrow, though the architect might be free after a meeting to have a look round late this evening. If the builder is not very convincing about the remedial action he's going to take, or the architect is not happy with what is being suggested, or in any way there is doubt in our minds that it can be fixed, it will come down and be redone. Simple as that.

I appreciate your comments.
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Re: Welding standards

Postby Roger Ramjet » Fri Jul 10, 2015 5:32 pm

somsip wrote: can see how much time this will take and that that end result will not be as strong as if it had been done right in the first place.

There are gaps where there should be welds, a good welder will be able to fill in a gap by running beads along each side, knocking off the slag and then joining the gab. In some cases the gap it too wide to even do that.
Most of the trusses should have been welded on the ground. It is far easier to weld with the rods pointing downwards than welding them with the trusses up. A verticle weld in high places needs a good welder, a good welding machine, safety helmet, leather gloves and the proper clothing.... Thais rarely use any of that and as the slag hits them they take the rod away from the weld, especially if it lands in their hair and you can't do a dance perched up on a truss that should have been welded on the ground.
Many Thais use very old welders that have been set at a certain amperage, which means they can only weld certain thicknesses of steel, otherwise they burn through the steel, hence they cannot run a bead, they just dab and tack, dab and tack because their amperage is set too high.
The other problem is they use the earth clamp to test for an ark, then they place the earth clamp well away from the where the weld will go, they know they have an earth, but they can't figure out why the weld will not jump the gap. A good welder will tack first then run the whole weld as the tack is acting as an earth between the two pieces of metal.
The newer types of inverter welders do not need the same amperage as the older ones. What I would have set my old welder to 110-115 amps I now set the new one to 85 amps. As long as it burns into both pieces of metal without burning through you have the correct amperage.
They also have a bad habit of not cleaning where they are going to place the earth clamp with a wire brush and then get a bad earth. You'll see them pushing and pulling the earth in the same place because they haven't cleaned the steel and have a bad earth.
And the final problem is they use too low a guage on their copper leads. Half the time they'll have joined old jumper leads into the cable to get a longer distance and have gone from a 200 amp cable to a 60amp or 80 amp cable and you can see the cables at the joint glow, it's another reason they tack, tack and tack instead of running a bead.
Good luck with the welder, I went through a number before I found one who could actually use all my equipment properly. I don't think he liked using it either, it was hit and miss if he showed up.
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Re: Welding standards

Postby MGV12 » Fri Jul 10, 2015 6:35 pm

somsip wrote:
MGV12 wrote:There is so much wrong with that job I wouldn't consider those who did it are capable of putting it right. Tearing it down and starting again is probably too extreme to consider but if the rest is the same as the pics it will take as long [maybe longer] to turn that dogs breakfast into a structurally sound one that will support your tiles adequately.


Sobering words. Earlier I'd accepted that this could be finished off in a way that would be to standard, but if each truss has to be cut, and a new angle welded onto it to provide a flush weld to the main supports, I can see how much time this will take and that that end result will not be as strong as if it had been done right in the first place.

Tearing it down and starting again is not too extreme. I'd be happy making that decision if the proposal to fix it is going to be unworkable or unsafe. It's maybe 8 days work and a bit of steel, most of which should be salvagable. The project manager is saying that this was a sub-contractor, but the responsibility ends with the builder on this, whether his team have done the work, or whether it's been farmed out.

We have a meeting on site with the architect, project manager and builder at 9am tomorrow, though the architect might be free after a meeting to have a look round late this evening. If the builder is not very convincing about the remedial action he's going to take, or the architect is not happy with what is being suggested, or in any way there is doubt in our minds that it can be fixed, it will come down and be redone. Simple as that.

I appreciate your comments.


It's an expense you could do without but in a country [not evident currently in many provinces] of monsoon rain and occasional horizontal storm winds you really need to be sure that your roof is good.

If you are able to afford the expense of getting that crap torn down and replaced with a structure under which you and your family can sleep easily .... no contest. If you are able [unusual] to get responsible parties to contribute to that cost even better.

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Re: Welding standards

Postby somsip » Sat Jul 11, 2015 10:43 am

Roger Ramjet wrote:There are gaps where there should be welds, a good welder will be able to fill in a gap by running beads along each side, knocking off the slag and then joining the gab. In some cases the gap it too wide to even do that.


Pretty much what the architect told us this morning, so good to see you confirm that. More in that on a separate update.

Roger Ramjet wrote:Good luck with the welder, I went through a number before I found one who could actually use all my equipment properly. I don't think he liked using it either, it was hit and miss if he showed up.


Lots of technical stuff you've said all makes sense, and overall it's coming over that the original welder has not done a good job and that the builder has allowed it to get to the state where we've spotted it. Again, more in a separate post.
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Re: Welding standards

Postby somsip » Sat Jul 11, 2015 10:44 am

MGV12 wrote:If you are able to afford the expense of getting that crap torn down and replaced with a structure under which you and your family can sleep easily .... no contest. If you are able [unusual] to get responsible parties to contribute to that cost even better.


Oh yes. Especially as the builder admits it's his fault and is covering the costs of making good. I'll add a summary with more about that.
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Re: Welding standards

Postby pipoz » Sat Jul 11, 2015 11:02 am

Hi Somsip

Sent you a PM

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Re: Welding standards

Postby somsip » Sat Jul 11, 2015 11:04 am

So site meeting today with everyone there. We arrived with the architect early, before the builder arrived.

On reinspection, we clearly have a problem. Some welds look okay to me, but there are many that are poor and not repairable in my opinion. The architect said the same. His opinion was that it was normal for the beams to be cut with a welding gun and the gap filled with weld (as confirmed by Rojer Ramjet) but that some of the cuts on our beams were so bad that this just wasn't going to work. I showed what I considered to be a good fit by using some saw-cut offcuts off the floor and though he stood his ground that weld-cut joins are strong enough, he admitted that saw-cut joins were best. The welder explained that the beams were just spot-welded in place for now and that they were going to be tidied up later, but the architect told him that some beams would need to be replaced as the joins weren't going to be up to standard.

The builder arrived so the same conversation was had with him. He said he could see that some of the work needed to be redone and was about to get it fixed, which is the first obvious crap excuse he's tried to make during the build and I'm so disappointed he's tried to get away with that one. He was told that he should have spotted the bad work on day one and got it fixed then, not left it until the whole roof was nearly completed using the same approach, and allowed us to find the poor work before it was fixed. He's admitted it is his fault and will stand any costs in fixing it.

The fixes involve tidying up any joins that can be tidied up, and replacing or recutting the beams for any that can't. If that means we have to take it all down, so be it, but I'd estimate that about 40% of joins can't be tidied up. Once he says the fixes are done, we will have another site meeting to review the fixes and the roofing will only proceed further when everyone agrees it's up to standard.

He's got the message. Up to now we've been very happy with his work and his approach, but the work on the roof is not good enough and he's been told that. So now it's with him to sort this out, and we'll continue to make regular site visits to see how it's going.

We're okay with this result for now. We will see if we are happy with the fixes when they are completed. Another forum member has recommended getting an inspection done by the SCB roofing experts which sound like an excellent idea as, as already pointed out, we can't risk having this lot collapse the first time a heavy monsoon blows through.

Thanks for everyone's input on this.
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Re: Welding standards

Postby somsip » Sat Jul 11, 2015 11:05 am

pipoz wrote:Sent you a PM


Got it thanks. Going out now and passing by SCG so will see what they have to say. I'll do replied to your other messages when I get chance :)
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Re: Welding standards

Postby MGV12 » Sat Jul 11, 2015 11:22 am

somsip wrote: Once he says the fixes are done, we will have another site meeting to review the fixes and the roofing will only proceed further when everyone agrees it's up to standard.



It will take a very good welder ... with good equipment ... to bridge some of those gaps. Personally I would ask for a demonstration of his welding skills on some scrap pieces before he goes up ... unless you like clambering around up there. Best also to get every one of those repairs inspected before they cover them with paint. Welding slag that is not removed [as it should be] can make a bad weld look good after a thick layer of paint is applied!

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Re: Welding standards

Postby somsip » Sat Jul 11, 2015 3:25 pm

MGV12 wrote:It will take a very good welder ... with good equipment ... to bridge some of those gaps. Personally I would ask for a demonstration of his welding skills on some scrap pieces before he goes up ... unless you like clambering around up there. Best also to get every one of those repairs inspected before they cover them with paint. Welding slag that is not removed [as it should be] can make a bad weld look good after a thick layer of paint is applied!


When I see the builder next, I'll make sure the inspection takes place before any paint is applied. If a gap is too big to be adequately repaired, the beam should be replaced or recut. But we need to ensure that's been done in every case.

Unfortunately today we didn't get chance to see if the SCG roofing expert can do an inspection, so we'll have to go in the week and see what they can do. It would be ideal if we can get this. We'll have to discuss options if we can't. Maybe I'll get researching more about welding so I've got some idea of what to look for.

Cheers.
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