> I wonder if the problem is that of the nitrogen "dissolving" into the material while it is under pressure in your
> tanks, then coming out of solution after application causing the large number of very small bubbles you are
> observing.  (Analogous to getting the bends if you surface too fast while diving, where the nitrogen dissolved in
> your blood starts to come out of solution forming bubbles in your bloodstream.)  What pressure are your tanks under,
> and are they left pressurized all the time or are they only pressurized during despensing?  If you release the
> pressure on your tanks and look at the two components, can you see bubbles in either of them?

> -----Original Message-----
> From: Rich Lasko [mailto:[log in to unmask]]
> Sent: Thursday, July 10, 2003 7:37 AM
> To: [log in to unmask]
> Subject: [TN] Potting Problems
>
> Good morning all,
>
> Background info...
>
> I am currently faced with a potting problem that I am hoping some of you can
> shed some light on.  We are currently using a Hysol US5500 compound.  (1 : 1
> resin & catalyst mix)  I am dispensing this from two (2) 5 gal containers
> located in 10 gal pressurized tanks (blanketed with Nitrogen only - no shop
> air introduced)  (We are using a PVA dispensing system).  We have checked
> all the tank and hose fittings/gaskets for any leakage to ensure no outside
> air / moisture is getting into these containers.
>
> Now the problem...
>
> Using brand new compound from the vendor, we can achieve the clear - amber
> solidified compound with virtually no "bubbles".  However, around the third
> day of production we start noticing hundreds of very small bubbles (smaller
> than the tip of a ball point pen ) in the compound.  I have had numerous
> conversations with both the potting compound mfg and PVA to determine HOW
> the material is becoming "contaminated" after a few days of usage.  Please
> note, once we get in a new batch of compound the cycle begins again.  (The
> first few days are perfect and then around the 3rd day or so...more bubbles)
> The potting mfg has discussed that this compound is susceptible to moisture
> contamination but we are struggling for answers because the dispensing
> system appears to be a closed loop system without any outside air
> introduction.
>
> Any thoughts or insight would be helpful.
>
> TIA...
>
> Rich Lasko
>
> Quality Assurance Manager
>
> Badger Electronics
>
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