Hi,

My company just delivered a couple of structural canopy type galvanized shelters, each with 4 pipe columns. Due to an engineering error, the columns were short, so we spliced them with full pen welds and took a lot of extra time to blend in the welds perfectly.
After galvanizing, the welds stood out like a sore thumb. I was amazed as to the exact detail in which the zinc emphasized the welds. The zinc thickness was about 1/16" to 3/32" thicker on top of the 7018 ground welds.
Allthough there is nothing wrong with a properly done splice, (working with the AISC code) and the customer included nothing about splices in the specs, the columns were rejected due to cosmetics.
Murphy's Law prevails again...

Tim

I have seen problems with this at our company. As you have described, welds look like they have not been ground smooth prior to galvanizing. From what I understand, there is really no problem other than cosmetic issues; that the controversy stems from people not understanding the process and what to expect from it. (A little information can be a dangerous thing)
The biggest issues come from people expecting a "Cadillac" finish on a bulldozer. Galvanizing is cheaper than an elaborate paint system and will normally last longer. However, it's a rude and crude process and it's actually amazing how good a galvanized job can look afterwards.

There usually is no complaint with fillet welds; not because they do not undergo the same reaction as groove welds, but because the thicker coating isn't noticable. Although I have heard one complaint about undercut being excessive when I know it was not a problem prior to HDG.

I suggest that you get together with your galvanizer to help your customer understand the issues. He should have a library full of documents that will be useful.
If the 3rd party inspector is "hard-headed" you may have to go over his/her head to the engineer.

Another thing you may want to do for future work is to take some photos of the steel before galvanizing. Then, if the customer has not seen it until after galvanizing, you can show what it did look like.

In years past, one DOT we had done work for required low-silicon electrodes for galvanized steel while another DOT did not. After we worked with that "system" for a few years, there was a reversal in the requirements. The DOT that required low-silicon electrodes dropped the requirement, while the DOT that did not mandate low-silicon wire then adopted the requirement. That happened about the same time, which was curious.

The FCAW wires we used to use for low-silicon welding was Tri-mark; I don't remember which one. Now we use Hobart Formula XL-550 which advertises around 0.23% silicon in the as welded condition. I have not found anything lower so far.
One wire, ARC 87, is listed on the internet as having 0.06% Si, but a check with our vendor indicated it was a typo. The % our vendor had in his information was 1.01%.
I had not looked very deep into GMAW electrodes because we don't normally use them but I thought some of those were low Si.

Chet