Electronics Forum | Fri Aug 28 08:52:13 EDT 2009 | duso02
Yes, you must thin Dow CC for any spray operations. We use Dow 2577 daily for multiple customers and we always thin it for spray operations and 2577 is considered medium viscosity. Dow recommends using up to 60% solvent (Xylene). Your 2620 is low vis
Electronics Forum | Thu Sep 10 15:01:28 EDT 2009 | mefloump
I currently spray DOW 2620 with my PVA650 without any problems. I do not thin it but I do have a distance between the coating machine and IR oven to provide a flash off period. I notice bubbles only when the flash off time is too short and the coatin
Electronics Forum | Wed Sep 02 11:36:22 EDT 2009 | kpm135
Is this an established process that is just now exhibiting these problems, or is this a brand new process you're just setting up? What is the rest of your process like? What is done to the boards before you coat them? Water washed? Solvent washed? Sa
Electronics Forum | Wed Apr 19 11:50:05 EDT 2006 | amol_kane
Hi BJ, Everyone's favourite answer...it depends! If the volume if large, masking boots will save you both, time and money in the long run. Custom boots are relatively expensive to buy, but they pay themselves over time by savings on masking tape. ma
Electronics Forum | Fri Oct 09 16:07:30 EDT 2009 | dlabelle
We use Dow 2620 silicone conformal coat applied with PVA1000 sprayer machine. If used on a daily bases, we have no problem. If we let the machine sit idle for over a week, we will get bubbles in the conformal coating. Sometimes, purging the line w
Electronics Forum | Fri Jan 25 15:51:26 EST 2013 | johng
Water soluble process, yes. The machine is old and fixed at 4 ft/min by someone way before me. Looking into ways to reverse that to allow for adjusting the conveyor. Trying to determine how the contamination gets onto the boards. So far testing has i
Electronics Forum | Thu Aug 27 08:34:50 EDT 2009 | floydf
I am having trouble with little air bubbles in my conformal coat. It ranges from a few pin sized bubble to looking like spit. We are using Dow 2620 silicone conformal coat applied with a PVA sprayer machine. The conformal coat comes in bladder bags t
Electronics Forum | Tue Aug 14 16:18:48 EDT 2018 | dontfeedphils
A couple of things to try as I just went through this myself. Checkout this link for pointers on plasma cleaning... http://www.nordson.com/~/media/Files/Nordson/march/Papers/The-Effects-of-Plasma-Treatment-Prior-to-Conformal-Coating-NordsonMARCH.p
Electronics Forum | Wed Jul 20 15:18:35 EDT 2005 | FW
Hi! We have both Dip & Spray conformal coating processes & have never done any kind of baking before the process! I am assuming the reason for baking would be the same - ie, remove any moisture on the brds since moisture will create failure of the co
Electronics Forum | Wed Feb 28 20:10:08 EST 2001 | mhunter
Checked the archives with no luck. Anyone have a reliable test method of verifying acrylic conformal coat cure. Using Humiseal 1B31 mixed with approximately 30% solvent, spraying with a Nordson. Thanks in advance.
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