Flux cover on flux cored welding?

Thanks in advance, Stan

FCAW is really close to stick welding as far as welding charistics go and about the same slag content. If your wanting a pure weld, then follow good procedures by removing all slag between passes.

About the only time you can get by on leaving slag is when short stopping, ie; to change electrodes or positions, and then you must be quick before the slag cools too much.

The only time I failed a weld certification test was because of a piece of slag I missed. It had to be fairly small as I did clean the root pass but by the time I put cover pass on it had grown to about 1/4" x 3/8" and just was under the surface of the bead when the cupon broke. You could follow the "V" of the slag, right down to the root.

T_Bone

I'd be interested in hearing more about something you said:

"It had to be fairly small as I did clean the root pass but by the time I put cover pass on it had grown to about 1/4" x 3/8"... "

Was the test in SMAW or FCAW? What causes the unnoticed speck of slag to lead to a buildup of slag that large? I consider this not good news.

If I remember correctly, you once mentioned that you had passed all your major certifications by the time you were 18. One thing I for sure don't have now is 18 year old eyes. If little specks of slag that you can't hardly see can lead to slag inclusions that can cause joint failures, I might have to start wearing my reading glasses when I weld.

All the best, Stan

That pictular test was a SMAW 3/8 plate test. The break out was on 1/3 of the test, horizontal position. Had the coupon been cut 1/4" shorter then the bad area wouldn't have been in the test.

When taking a distructive certification plate test, the two coupon's are cut any where in the weld area starting 1" from either edge. Cutting from 1" of the edge allows for cold lap on a plate test.

I believe I wire brushed before making sure all slag had been removed thus the wire brushing burnished the slag surface to appear as sound steel.

A full explanation of inclusions can be read in my article named "Welding Misconceptions".

What I should include here is that a small piece of slag can be hidden with-in the molten weld puddle upon cooling from using to long of arc length or incorrect electrode angle. This will be noticed as flutter in the molten puddle or like the molten puddle is trying to run around the inclusion and not thru the inclusion. When this flutter is noticed, stop and use a grinder to this part of the weld to dig out the inclusion to sound metal.

If you fail to clean out this inclusion, it will then continue to grow from each sucessive pass thus can bridge from the root pass to the cover pass as it did in my test plate. Note that on each pass you will have problems with the inclusion in exactly the same spot every time. That's why I always stress to play close attention the the molten puddle as it will tell you when there is a problem.

Yes I did first take a series of certification tests at 18 but that was for one job site and AWS was not such a huge influnce at the time like it is now. What previous AWS certifications can do is open the door for the next job as you have already demonstrated your welding abiltity.

AWS now requires a recertification for several reasons like a weldor that hasn't beening welding with-in the past 90days, a change in welding procedures or processes, etc; etc;

That also holds true for AWS CWI's(certified weld inspectors). A CWI is allowed to renew there license two times without retesting, a total of 12yrs, as long as they can summit proof of employment in the welding industry. In fact now that I have been retired for 10yrs I couldn't even qualifiy to retest as a CWI as I didn't have 4yrs of recent employment history even tho I held a CWI license for 12yrs. lol

T_Bone

• Welding Misconceptions