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Up Topic Welding Industry / Welding Fundamentals / SMAW CWB TESTING 1G
- - By FloydH19 Date 11-13-2015 00:03 Edited 11-18-2015 06:52
Tips on cwbs: 1g
3/8" plate (6" x 6")
Single Bevel
1/2" gap
1/4" x 2" x 9" backing strip
no reinforcement greater than 1/8"
(ALL WITH 5/32  E7018)

Parent - - By welderbrent (*****) Date 11-13-2015 01:11
Hello Floyd,


As I stated in the other thread, please only post a query once even if you aren't sure where it fits in best.  If it is really out of place the mods will move it for us.

What are they calling 'undercut'?  If it isn't at least 1/32" deep and especially on a pass that is going to be covered I don't see the problem.  But then, I'm not in Canada (BTW, don't be sorry you are from Canada.  Just because I am glad to be a US, American, citizen doesn't mean I think less of others.  We deal with the hand we are dealt.  I had nothing to do with my birthplace and neither did you.  Beyond our control.) 

Weave or stringer?  Well, again, that depends upon what one 'CALLS' a weave?  Stringer is pretty straight forward yet may overlap with weave depending upon the definition applied to 'weave'.  Normally a perfectly straight bead is not the only way to do a stringer.  A slight weave motion does not have to be qualified as a weave pass.  Most all of us use at least a slight side to side motion to a pass.  It normally must pass a certain criteria before it is termed a weave.  But I don't go for the 2X, or 2 1/2 X, the diameter of the electrode.  Pretty flimsy way of describing a weld width and making a determination about weave or stringer.  Especially when people start trying to make the same application to wire electrodes.  Really? 2 1/2 X the electrode for a .045 wire is now a weave?  NOT. 

Part of your question would be answered by answering some questions as they pertain to the work:  What code is applicable?  See, Bridge Code is different from Structural.  Maybe not in Canada but it is down here.  What do the Job Specs say?  They will give guidance at times that isn't found in the applicable code.  Are there limitations on heat input?  That will really effect the use of weave passes as they are going to have a higher heat input that may be a problem on some jobs.  Is there an Inter-pass temp maximum?  Just as heat input this is effected by the kind of pass run. 

Personally, from the sounds of the joint (mainly the 1/2" root opening with a single bevel on 3/8" plate)  I don't think I would feel comfortable just 2 weld passes.  Again, are you calling each bead a pass?  Or are you referring to each 'layer'?  There can be several passes in each layer of weld on heavier materials.  Don't confuse pass/bead with layer.  As the joint gets wider with the bevel opening angle, each layer will take more passes/beads to complete. 

Run a pass, let cool, chip slowly and lightly so as not to peen/work harden the weld, look it over, run the next pass.  This should allow for enough cooling to keep your coupon from getting too hot. 

Oh, right off hand, I believe we would call it AWS D1.1 testing only ours is usually with a V groove instead of a single bevel for the down flat position with only a 1/4" root opening.

Lets see what some of the others have to say.

He Is In Control, Have a Great Day,  Brent
Parent - By FloydH19 Date 11-16-2015 07:07
Thanks Brent For the info about the posted, I didn't know . And as for the understanding of pass/ bead and layers I was getting a bit mixed up. And there is no  limitation  on heat input so I have been running it at about 170 amps. I will keep in mind about the SLIGHT side to wide motion as opposed to a harsh  zig zag let's call it . Keep in touch throughout the week thanks
Parent - - By Lawrence (*****) Date 11-13-2015 12:01 Edited 11-13-2015 12:08
This is going to be easier than you think

First... Welcome the forum

The single bevel test is the way it is for a very important reason... This test assembly requires you to make a fillet weld!  Also a groove weld.. All at the same time.

The non-beveled edge is the one giving you trouble today eh?   Well young man... It's just a fillet weld  :)   So don't let it intimidate you at all.

Forget weaving or whipping...  This test assembly requires a "split root" Meaning, a separate root pass on each plate, each root pass must have a start/stop, and be inspected as a "hold point" The fillet must be small so that it does not touch the other plate, so you must be careful.. Never more than 5/16"   The test proctor or CWB rep will measure your root pass fillet, and inspect the two start/stops... They always do this, so don't be nervous, just get used to it.

So back to the undercut...  Just practice some fillets in the same position as the test eh?  Practice controlling your rod angle and travel speed to decrease the undercut, keep the arc length short to also help with the undercut.

If you are using 3/32" electrodes for your root passes this will be very easy... If you are using 1/8" electrodes it will still be easy, you will just have to pay a little closer attention to fillet size on the first root passes.

It's a little bit different than an AWS test...  But not really harder... Remember the 3/8" CWB assembly with a fillet qualifies a welder for unlimited thickness!  (according to W47)

If you have more questions... Just come and ask


Edit:  I missed the part about 5/32 electrode...  This makes it a bit more important to watch your arc length, travel speed and rod angles, so that you don't make your weld too large on that first fillet...But you have an extra wide root opening so your rod will fit into the groove with ease... Again just practice fillets in the same orientation as the test... Getting the size and profile you like.
Parent - By welderbrent (*****) Date 11-13-2015 15:40
Forgot that their test was that way for good reason, fillet and groove at the same time.  Thanks for the reminder Lawrence.

He Is In Control, Have a Great Day,  Brent
Parent - By FloydH19 Date 11-18-2015 00:25
Hey Lawrence, and Brent, forums awesome so far! thanks for a quick respons

so first day back in the shop i prepped about 4-5 good CWB coupons, and then practiced some normal fillet welds with E7018 5/32"
1. I am now watching the top of the puddle when welding the first square side, seeing the undercut get filled (wathching it tie in nicely with the metal), and i'm producing a nice clean 5/16 fillet. I saw a little crevice right in the corner of the backing strip and square edge and am wondering, is that only because i stopped there? or is there lack of fusion all along that joint, a dye pen test will show i'm sure. I am on a nice miller machine so tomorrow I think if I turn my DIG up ( it goes from 0-100, 0 i'm guessing, is "soft") it will penetrate more in the joint (hard to find the right terminology to explain yourself ahah), OTHER than those points my root  is going pretty well..

2. As for my Fill/cap, I am getting used the the weave (side to side), and really just getting used to each jump/zigzag being consistent. Hoping no spots along the side of the joint are missed, leaving a little divot. I also clued in on, the more pressure you apply feeding the rod, the more metal will be deposited. So i go with 2 passes for my fill, doing a side to side while putting slight pressure building up material. Its starting to look real nice and hopefully i can knock it down to one fill pass soon. and as for my cap pass, when starting again after a stop, do i begin welding exactly where i left off or the last point/zigzag/jump that i did before i stopped ( if that makes sense )

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