by Ron Joseph
October, 2005
Use of Silicone Sealer in Spray Booth Construction -
Fish Eyes - Cratering Q. I recently attended the paint training class offered by Akzo Nobel and heard
some horror stories about silicone contamination in paint facilities. Of particular
interest was a problem caused by contaminated thread (which passed over a spindle
lubricated at some point with silicone) that was woven into filter bags. Very
difficult to track down. My concern was introduction of silicone during construction
of a paint facility. Could a silicone containing material such as pipe dope
or RTV silicone sealing in ductwork cause problems? I asked an engineer form
Boeing if they had ever encountered such a problem and he told me Boeing put
a prohibition on silicone into contracts when constructing paint facilities.
As you are probably aware, Warner Robins is building a new paint facility, so
I asked the chief engineer for the project if there was any language to that
effect in our contract. The short answer is no, and he was unaware of the problems
silicone can cause. When I asked the folks at the AFCPCO if they had ever encountered
any silicone problems from construction of paint facilities the answer was no,
of all the sites surveyed for the Facilities Hand Book they put together, there
was no mention of any silicone related problems. Hence the question, have you
ever encountered a silicone problem as a result of construction practices? Is
concern during construction warranted, or is contamination always after the
fact, introduced into a facility somehow? Or is silicone contamination rare
in general? Thanks.
A. I'm sorry it has taken so long to get back to you, but I mislaid your email.
I have not heard of paint booth problems when silicone is used as a sealer,
but I also confirm that silicone is a poison in any paint facility. Unfortunately,
when paint cratering (fish-eyes) occurs it can take week or months to identify
the source, and often the source is never found. If I were to be retained to
solve a cratering (fish-eye) problem I would look for all sorts of sources of
contamination before looking at the sealant in the sheet metal of the booth
or ducting.
Therefore, if at all possible, I suggest that you keep this elusive chemical
out of the system. nobody will thank you now, but they surely use lots of four-letter
expletives if a problem occurs and they dfound out who initiated it.
Regards,
Ron Joseph
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