Welding Wide Flange Splices 4

[sedonas]

When you weld two wide flange together by cutting them square... would it make sense to further strengthen the web by putting cover plates over the web? Or over the flange?The purpose of flange is for tension and compression.. the web is supposed to be only for shear? Which to focus more in welding.. But if you weld cover plates on the flange.. won't it weaken the flange by having many welded regions.. how do you weld your splices (that involves no bolted connection)?

 

[sedonas]

This is another weld on other wide flange splice that is direct.. it is satisfactory?

Has it more strength if the splice in the web has horizontal weld than simply cutting the wide flange and welding it square?

 

[Ron]

Your welder is full of crap! The weld you showed is not the "back side".

As for the electrode, an E6011 electrode is a penetrating electrode that can be used in all positions. It is a versatile, "all purpose" electrode. It provided deeper penetration; however, it also yield greater porosity and slag inclusions that can lead to nondestructive testing rejection. The welder must know how to use this and other appropriate electodes for the application.

 

[sedonas]

The welder is a senior who welds 50-storey high rise. Our welder average salary is $15 a day working 10 hours. They don't even eat breakfast because no money. I wonder if welders in other places are richer.

I plan to subject it to x-ray testing. How reliable are x-ray testing and have you guys done any of these? Can you share any picture of the x-ray of the weld?

 

[CANPRO]

sedonas, I don't have much experience with x-ray testing, but I believe the results are only as reliable as the person interpreting them, which takes some experience to get right.

May I ask what part of the world this project is located.

 

[sedonas]

Canpro.. Indonesia.

So backside of welds should look the same as the front?

 

[Brad805]

Those of us in North America will have difficulty wrapping our heads around this problem. In North America, whom does what weld is governed by rules. Welding is a trade and one must go to school, and apprentice before being certified by whatever association they are registering with. Yes, welders are paid higher in North America. My nephew welds in the oil field and he has made upwards of $120/hr. He does work the same hours. That said, he would never show a picture of such terrible welds. I would not step foot into a building containing welds by that character if he is building anything larger than a dog house.

The comment from ehow is terrible. Weld regions must be prepped before welding. Paint, dirt or grease must be removed with a wire brush or grinder before welding. That is what the welders helper does. If you see a welder trying to weld thru paint or grease, grab a stick and give him a whack.

I wouldn't bother with testing until the welds look better. You will find all sorts of inclusions and slag based on what you have shown thus far.

 

[sedonas]

All the wide flange were first painted at the shop and rust primered before delivery so yes all have paint on them. The welder directly welds on the welded parts without doing any preps. Let's say they are not dirty and no grease but only have paint.. won't the thousand of Fahrenheit temperature of the weld evaporate those paints away? Or would it be like zinc on galvanized steel where the zinc can affect the penetration of the weld?

 

[gtaw]

Generally there is nothing in paint that is beneficial to the weld. There are components in the weld, i.e., hydrocarbons, that can introduce hydrogen into the weld. Hydrogen can cause delayed cold cracking. Other compounds can cause porosity and if the paint is thick, can interfere with proper fusion between the molten weld metal and the adjoining painted base metal.

As mentioned by others, the base metal has to be properly prepared before welding. Since these are suppose to be complete joint penetration groove welds, the base metal should have been beveled to permit proper joint penetration. All paint and other contaminates should be removed from the groove and the adjoining surfaces (1 to two inches from the edges of the groove). The welder can weld from one side, in which case he could have used a backing bar to support the molten metal as he deposited the root bead (first bead deposited). If the joint is to be welded from both sides, the first side would be welded and then the second side would be back gouged to sound metal before welding the second side. Back gouging is an operation where the welder uses a grinder (or other means) to remove the unfused metal to a depth where sound metal is found (from the weld deposited on the first side). The back gouging operation ensures the welder is depositing weld on good sound weld metal and not simply depositing weld metal over slag.

All of this discussion is meaningless unless there is a skilled welder available to make the welds. When there is a question about availability of skilled welders, a bolted connection is a valid option.

Best regards - Al

 

[sedonas]

For a wide flange w8x21.. is there a table how to put the bolted connections for square splice that would give the same moment and shear strength as the original section? How many bolts per side.. spacing and the size of the bolts?

 

[kingnero]

Xray on this crap will give no workable results, as the surface is too irregular. Nor will any other type of ndt, for the same reason. This should be done by a "coded" weldor, and with hi-quality, low-hydrogen rods. Google for farm code pdf, this fits right in.

By the way, pay nuts, get monkeys. $15 a day?

 

[Ron]

Agree with KingNero....radiography will fail this weld. It has improper profile, incomplete fusion, poor penetration and no doubt, slag inclusions. That would make it fail essentially any radiography criteria you apply to it.

Further, the fit-up is poor. The flanges are offset and warped.

Just because your welder has welded on high rise projects doesn't mean anything. He's obviously not very good at it and I would suspect any weld he has made on those high projects!

As for welding wages....most welders in the US are required to be certified and make a lot more money than that.

 

[sedonas]

The following is really backside.. it's not direct weld on the 0.250" (6.5mm) thick web:

I argued with the welders and even nearly quarelling with them. They said it's backside and the weld got thru the 0.250" thickness. They use 6011 on the front side which is this picture (before coverplate was put):

The first earlier image is the back side which shows weld drops.. isn't it just the excess welds pushing thru to the backside?


Won't the 2 images above (front and backside) show that there is full penetration from the front side to the first backside piture with drops?

I need to know details so I know how to argue with them.

This is the standard technique of welding in my country so I'll learn what is proper and review it. Thanks.

 

[Ron]

Just because you have full penetration through the cross section does not mean you have a good weld! There are numerous criteria that define a good weld....complete penetration is not one of them. If your radiographic testing is as incompetent as the welding, then you probably won't know that you have a bad weld!

 

[sedonas]

gtaw wrote:

Generally there is nothing in paint that is beneficial to the weld. There are components in the weld, i.e., hydrocarbons, that can introduce hydrogen into the weld. Hydrogen can cause delayed cold cracking. Other compounds can cause porosity and if the paint is thick, can interfere with proper fusion between the molten weld metal and the adjoining painted base metal.

It's not exactly paint.. but epoxy primer.. the steel sections were epoxy primered before put in place. It's difficult to put epoxy primer when the structure are already in place. So my concern is not exactly paint.. what's the behavior of epoxy primer when it's on steel and they are welded.. would the epoxy just evaporate? Would some part gets into the weld? I need to know this important because we were installing purlins below the wide flange.. Should I not let the purlins be epoxy primered before putting in position? The purlins will be connected to below of the w8x21 distance every 0.6 meters.

 

[Brad805]

Time to make a decision. The workmanship in your country and this groups is fundamentally different. It seems you have very few rules in your country, so why our opinion matters is confusing. Frankly, if I worked in your country and was to accept the same degree of liability we do here, I would find a new profession.

 

[sedonas]

Someone asked here how the steel got from factory to welding. In our country. Steel sections were distributed in factory. I just visited one this morning when I made the order requested by the designer.

Here are the vertical C section that will be connected below the wide flange which would act as bracing.

As you can see. All the steel stocks of the company are not primered in any way but bare steel. So should we first primer it before welding it.. or should we weld it first then primer it (this will be more difficult as the worker has to climb every steel section). We can't primer it then grind away the primer in the welding region because that will put me in quarelling mode with contractor for delaying the project so much.

The welders who did the wide flanges have left already. They have zero warrantee or liability. The old contractor has no liability either. So it's up to me and senior designer to reinforce the sections.

Now I need to know something specific.. how does epoxy primer interact with bare steel and welding? Couldn't it just evaporate? Do you consider epoxy primer as paint? What part of paint can affect the weld? Does the epoxy primer has the same component as the paint ingredient that can affect the weld?

Thanks for those very helpful assistance. Your opinions much appreciated because the laws of physics is the same in different countries. This is the last time i'll allow any welding after this wall cladding support welding job.. after that. I will never trust local welding again and will never do steel sections again but only reinforced concrete due to the substandard quality in my place.

 

[moltenmetal]

The initial photo you've posted seems to show no weld of the top flange whatsoever, unless my eyes are deceiving me. It looks like the welder merely butted the two pieces of wide flange together without any gap between them, and with no attempt to prepare the joint, and then deposited a very ugly partial penetration weld on the web only.

The top and bottom flange need to be full penetration welded for the member to have any meaningful strength!

It looks like the welder went back and simply dumped some weld metal on the top and bottom surfaces of the top and bottom flange where the pieces had been originally butted together without a gap between them. There was no attempt to grind a groove or bevel at that joint. That is not a full penetration weld! Regardless what type of electrode is used, you will only fuse the very top and bottom of the joint in each case, leaving a large gap of unwelded steel in the middle.

The welder is obviously untrained and unguided, and the situation is very dangerous. For each of these bad joints you are seeing, there are probably ten that you haven't noticed yet. Even if you fix the problem by reinforcing the splice joints from below, you need to do a thorough inspection of the rest of the work- every other weld this "welder" did.

There are primer paints that are intended to be "weld through". They are designed so that they do not leave a residue which is damaging to the deposited weld, though they can still generate some porosity or other flaws. They are just primers, and are not very durable- they provide little meaningful corrosion resistance beyond the erection period.

EPOXY is NOT a weld-through primer! If there is epoxy on pieces of steel, you MUST remove it by grinding for a sufficient distance on either side of the welded joint before you weld, or else you are very likely to generate flaws in the weld.

 

[sedonas]

moltenmetal.. thanks for the input.. i'll get an expert welder to repair it... can it work if he would grind a bevel to the top and bottom flange of the present incomplete weld and do full penetration weld on it?

I have argued with the old welder crew so many times. I told them the flanges of wide flanges have tension and compression zones.. they don't understand what I'm saying.. they only focus on the web.. and they don't use any grinder but only acetylylene to cut steel.. this is the reason why I wrote this thread to ask if the flanges are as important as web. I'll also ask the contractor to read this message.

Their reasonings is that the thin 0.07" or 10mm can be penetrated by the 6011 electrode and automatically do full penetration welding because the flame reaches the other side. But then is it not true that if the welding can melt the entire 10mm flange.. it can fuse them from the outside? Why.. does it have to be filled up for any fusing to work at all?? Please answer this because this is my most important question. Thank you!

 

[Tmoose]

Is your weldor trying to do each weld in one pass?
What is the welding machine they are using? What are the settings?



The flux etc needs to be cleaned off for proper inspection.

Here is Lincoln Electric's basic video about visual weld inspection. It is aimed at Boy Scouts getting their welding merit badges.

https://www.youtube.com/watch?v=Ncguc7THEUY

I think the "welder" needs at least to spend a few days running beads flat and vertical and making pad welds on 10 mm material to achieve at least basic proficiency. Even then, I don't think he should be allowed to work on your job again.

I think the "expert welder" is going have to do a LOT of grinding or arc gouging to fix those welds. And probably cut out and replace some sections entirely.

Pages 32 thru 33 here discuss a minor case of one of the obvious deficiencies of those welds you are having to deal with.

http://supplier.huntingtoningalls.c...lders_Visual_Inspection_Handbook-2013_WEB.pdf

Note the corrective action of cleaning the weld area.
The lack of cleanliness is NOT causing most of the problems however.

I envision the beam welding requiring be done in 3 different positions. Flat, vertical, and even overhead.

Here is a video showing some very good "vertical up" welding in process, and proper surface and edge preparation for 3/8"/~10 mm plate. Full penetration welds generally require some beveling or other edge preparation and multiple passes. They are NOT done by blasting thru the material in one pass.

https://www.youtube.com/watch?v=1QxT7JUjs94

Overlook the extremely uniform weld surface appearance. There is some leeway there.
Can you see how the weld completely fills the space between the plates, and fuses completely with each plate?

here is another series, from Lincoln electric. OK, but they spend too much time recording far away.

https://www.youtube.com/watch?v=oCS9t2CB6Vg

They are all using 7018 electrodes. As I recall the flux removal is much easier than 6011.

But notice the uniform bead, slightly convex, fusing with each side of

 

[Tmoose]

"Full penetration" joint in flange and web. Nacker strips left in place.

http://weldingweb.com/attachment.php?attachmentid=64971&stc=1&d=1301145523

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1:28 " the weld on the left there is obviously just crap"

https://www.youtube.com/watch?v=JEFd56ofHos

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This is >> generically << what a bolted I beam splice looks like.

http://i51.tinypic.com/2nlfgvb.jpg

There should be some serious engineering behind it.