T Joint alum filet 2"by 1/8th

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I am an Instructor of welding at a school in Fl, .  I am having a problem with a weld test that I have been using for years. This is the test. We take 2" x1/8th  flat bar four in, long fabe, the T joint and weld 1 filet pass then we cut this in half bend one half in to the weld the other away from the weld . Then we check at the cut end for penetration in the vertical and flat horizontal pice.  Is this a good test for interleave students . My new inst, wants 2"x1/8 materal with three filet pass on each side to pass tig alum. What are your thoughts?
Reply:One pass is sufficient for 1/8" material.My name's not Jim....
Reply:Hello anumay64, your initial test description serves a better purpose to educate the students overall than the 3-pass weld scenario that you have described that is suggested by your new instructor. Your method will produce view-able results that can aid in explaining the intent of making proper welds and the methods to check for this. Another item to remember is that a single pass fillet correctly sized is less likely to compromise the materials tensile properties than a 3-pass scenario (causing excessive metallurgical changes). Also, back-bending the fillet will provide a good look at root penetration across the entire length of the specimen. The "end check" or intermittent cuts along the joint, if you can properly etch the parts, will also show the students the effects of various approaches to welding, ie. torch angle, amperage, possibly travel speed and a host of other technique issues. I don't know that a face bend is especially beneficial so much as a full-length back-bend. Regardless, being able to break the bead or show fusion issues between parent metal and weld metal is a great result. You can also often "see" gas bubbles trapped in the weld metal that can be discussed with regard to cleaning and other pre-welding issues that often result in these discontinuities. Triple-passing on a fillet like the one you have described by your new instructor only helps to teach multi-pass beading if that is the goal. Welding both sides of the fillet makes it that much more difficult to do a fillet break test readily and mainly yields a visual result, instead of visual and destructive. Yet, I truly doubt that even that can be accomplished properly due to the lack of a sufficient volume of material to deal with all of the excessive heating generated by 3-pass welding on something that thin. Now, if students are taught to use chill blocks or other types of heat-sinks in conjunction with this exercise, along with single-sided welding of the fillet, I could see some possible benefit. These are just a few things that you could discuss with him to address your differences in method. Good luck and best regards, AllanLast edited by aevald; 11-13-2014 at 06:39 PM.aevald
Reply:Thank you both I wanted to be shore what I was saying is legit .  on it goes.
Reply:1 pass on 1/8th is sufficient, doing a 3 pass on it will save you material when practicing.Nothing Ever Got Done By Quitting, Never Give Up.