Electronics Forum | Thu Mar 31 20:50:13 EDT 2011 | tkirk
I disagree with the others about conformal coating before potting. Some of the softer urethane potting compounds can absorb water leading to caustic nastiness in the voids under the parts. Conformal coating can help fill/seal the voids and keep the n
Electronics Forum | Wed Sep 24 20:04:44 EDT 2003 | Michel Moninger
http://www.mgchemicals.com/products/832.html Loctite makes a version too, if I recall. Designed to be tamper evident, but yes, rework is a bear. We had similar results using one of Lord Chemical's urethane potting compounds. It was a filled black fi
Electronics Forum | Tue Jan 24 21:07:17 EST 2006 | davef
We all genuflect to Graham Naisbitt, a generous contributor to SMTnet. Moisture-curing urethanes may form minute bubbles if the coating is too thick or the coating environment is too humid. So, tell us more about your urethane and the method you u
Electronics Forum | Tue Jan 24 10:24:18 EST 2006 | kmorris
We've got a problem here, where we're hand spraying a urethane conformal coat on over a rectangular inductor. The inductor body is a plastic tube, with potting to fill. The top is not always flat (sometimes concave). The problem is that bubbles appea
Electronics Forum | Thu Apr 21 11:43:03 EDT 2005 | davef
We understand the problem of trying to coat over RTV. We have seen the same problem with acrylic and urethane coatings not wanting to stick to RTV. Some acrylics seem to be worse than urethane. Since this is a new product, may be you could pot your
Electronics Forum | Tue Jan 24 19:00:15 EST 2006 | MikeF
Graham Naisbitt is definitely an expert on conformal coating, he has posted answers here for years. Check your material to see what the cure mechanism is. Most urethanes need moisture from the air to cure, the higher the relative humidity the faste
Electronics Forum | Tue May 06 15:53:52 EDT 2003 | bremerg
The coating is pliable and is air cured for 24 hours. The potting compound goes into the top assemnbly in 3 diferent stages. The circuit boards are coated using urethane type conformal coating. The unit is also placed into an ESS chamber -40� to +
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