Agreed, the strength of urethane is to be very solvent resistant so it's
going to take a strong stripper to work sufficiently. Which usually means
potassium hydroxide. The last UR coated boards I stripped for LMCO, I used
Humiseal stripper. Wasn't pretty but it was effective. If you are only
doing small rework or replacing a single component, using CrystalMark's
services will ease the pain.

Lloyd Duso
Plant Manager
Diamond-MT
(814) 535-3505
www.Diamond-mt.com

On Tue, Jul 17, 2018 at 2:27 PM, Stadem, Richard D <[log in to unmask]
> wrote:

> Pardon my ignorance, but what is the issue with the stripper having
> potassium hydroxide in it?
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Steve Gregory
> Sent: Tuesday, July 17, 2018 11:55 AM
> To: [log in to unmask]
> Subject: Re: [TN] Urethane Coat Remover
>
> Hi Kate,
>
> Stripping Urethane coating as you know is very difficult to strip. If you
> have a stripper that works well on the urethane, you then have to be
> careful whether or not it will affect any other material on the assembly. I
> found one that doesn't have potassium hydroxide in it. I've never used it,
> so I don't know how well it works:
>
> https://www.miller-stephenson.com/product/conformal-coating-stripper/
>
> These are the ingredients:
>
> Material
> CAS No.                    Approx. %
> 1,1,1,2,2,3,4,5,5,5-Decafluoropentane (HFC-43-10mee)
> 138495-42-8               22 - 30%
> Trans,1.2-Dichloroethylene
> 156-60-5                     45 - 50%
> Methanol
> 67-56-1                       4 - 10%
> N-Methyl-2-Pyrrolidone
> 872-50-4                     18 - 22%
>
> When we had a big project where we had to rework a bunch of boards that
> were urethane coated, it was an engineering change where we had to remove
> and replace parts on boards that were urethane coated we purchased a
> micro-abrasion station from a company called CCR Co.
>
> http://www.ccrco.com/
>
> I think I remember it being recommended by a Lockheed engineer. Anyways the
> station worked great. The media used in the station is ESD safe which is
> something you need to worry about when using a media-blasting station.
> Urethane is best stripped when it is aged a bit. When it is freshly applied
> the beads tend to bounce off. I remember if they didn't strip well I would
> put them into an oven for a few hours to make the coating become a little
> harder so it would strip easier.
>
> Steve
>
> On Tue, Jul 17, 2018 at 5:45 AM, Ekaterina Stees <[log in to unmask]
> >
> wrote:
>
> > Hello Technetters,
> > Does anyone know of a chemical remover for urethane conformal coat that
> > does not use potassium hydroxide as it's active ingredient?
> >
> > Thanks,
> > Kate
> >
>
>
>
> --
> Steve Gregory
> Kimco Design and Manufacturing
> Process Engineer
> (208) 322-0500 Ext. -3133
>
> --
>
>
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