I have to agree with aevald here!!!
The only other questions I would like to ask Richard is with respect to the bends, let's assume everything was correct as far as the bending of the coupons is concerned... In other words the correct mandrel & coupon dimensions...
1) What type of groove joint, opening, angle etc. was used?
2) Were the failure in the root or face bend(s)?
3) Could you better describe the "strongback" you welded on the root side of the weld and how it's related to the joint itself?
4) Was the spool of FCAW electrode wire properly stored?
5) Did you have the correct mix of shielding gas and was the recommended flow rate used?
6) Would you please describe the specific type of failures?
7) What were the welding power source output parameters set to and the diameter electrode wire being used? Electrode stickout? Position of the test joint?
In other words, even though this is alot to ask but, the more info that's given to us, the greater the possibility that we can give the proper guidance for you so that you can ultimately resolve your problem.
So please do'nt think that I'm pestering you! I'm just echoing Allan's reply in my own words.
I do believe Allan is on to something with him leaning towards the possibility of not performing the bend tests properly however, I'm just attempting to cover all the bases and if I missed something, then someone else will chime in and add another potential route to finding the solution to your problem.
Respectfully,
Henry