February 4th, 2021
Passing the gas retention portion of the insulating glass (IG) certification test can be a challenge. It is a very demanding test. The IG units must average 90% fill rate at the beginning of the test and 80% after, while enduring a rigorous series of weather cycling procedures. Here are four tips to help you achieve optimal results.
- Before you begin, conduct an audit. Gas retention is perhaps the most unforgiving portion of the test. When it comes to moisture entering your units, you have desiccant inside ready to snatch it up helping to prevent the units from fogging. But if you have argon leaking out of your units, there is no magic ingredient that will prevent it from escaping. It is gone and your argon content is forever diminished. Therefore, conduct an audit of your fabrication procedures including glass cutting, washing, spacer application, sealing, gas filling and final inspection to make sure you are following best practices. Invite your key suppliers in to conduct audits as well if they offer this service. An extra set of eyes may find mistakes that are overlooked by your own people. Part of the audit should include the dunk test. Read my previous blog on this. Randomly select a few units and dunk them in a tank of hot water. If you see bubbles, then you are doing something wrong. The bubbles are argon escaping, which means that even if you pass the initial argon content portion of the test, you will like likely fail the 80% requirement at the conclusion of the test.
- Calibrate your gas filling machine. Gas filling machines are smart these days and can tell you the exact second that your units are filled with digital readouts giving you the exact amount of argon that has been filled. But this is meaningless if you forget to calibrate your machine. Follow the manufacturer’s guidelines and always calibrate before gas filling your test units.
- Seal your units immediately after gas filling. The sooner that you seal each unit after the gas filling operation the better. If a corner or gas filling port needs to be sealed, then do it immediately. If a secondary sealant is to be applied, then do not hesitate. Argon is heavier than air, so make sure your gas filling entry port is located on the top portion of the unit facing upwards if possible. If not, the gas that you just filled into the unit will come flowing out of the port as soon as you remove the filling wand. We cannot see argon, but just think of it as behaving just like water. Imagine what water would do if you were filling with water. The two behave in a similar fashion. So, imagine a fish tank filled with water – what would happen if you had a hole in the bottom right portion of the tank and you left it open while waiting to seal it later!
- Get your hands on a Spark-Lite unit. If you do not own one then beg, borrow or buy (do not steal) one. I affectionately call mine “Sparky.” My Sparky is an instrument that sends a visible spark, not unlike that seen in a Frankenstein movie, across the air gap with a digital readout telling you how much argon is in each unit. It is a non-evasive test. It does not compromise your units by poking a hole in them. It is also the same instrument that the test lab will use to measure argon in your units during the certification test, so it is somewhat like the last word on argon content. However, just like your filling machine, your Sparky must be calibrated periodically as well.
So, do these four steps and avoid the frustration that could result from failing the argon portion of the certification test. In my opinion, argon retention is the toughest portion of the IG certification test. If you pass it, then you usually pass the other major parts of the test as well. Now, as to passing the chemical fog part of the test, that is a blog for another day!