Date: Fri, 18 Mar 2011 14:57:21 -0700
Reply-To: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Subject: Re: Instrument Cluster Printed Cirucit repair
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Sounds flabulous Dahling !
how's about I send you one ..
you repair it ..
and bill me reasonably ..
hmmmm ?
Aloha,
Scott
www.turbovans.com
I have several old flex-circuits if that's what you mean by what I call
Printed Circuits ..
like for you to play with ..
hey ! I could pay you in old printed circuits ..yeah !
----- Original Message -----
From: "David Beierl" <dbeierl@attglobal.net>
To: "Scott Daniel - Turbovans" <scottdaniel@TURBOVANS.COM>
Cc: <vanagon@GERRY.VANAGON.COM>
Sent: Friday, March 18, 2011 1:56 PM
Subject: Re: Instrument Cluster Printed Cirucit repair
> At 03:51 PM 3/18/2011, Scott Daniel - Turbovans wrote:
>>is anyone repairing that one spot...where the plug plugs on ? The strips
>>of
>>copper get ripped or damaged there ........which is why I always lube and
>>treat that
>>connection.
>
> Repairing that particular spot would be quite a difficult repair, better
> to cut the damaged part off, carefully skive off little windows in the
> plastic layer *on the thin side* exposing the foil, clean and very
> delicately solder wires there and secure them to the remaining tab of
> flexible circuit and run them to a DB25 connector. As long as you keep
> physical stress of the wires where they solder to the individual foils on
> the flexible circuit your connector troubles will be over as the DB25 is a
> very robust connector. You can get them with crimp pins that insert into
> blank shells, or fixed pins with solder tails which I recommend for
> one-off jobs like this. Suggest wiring up the connector first, using
> flexible wire and paying *serious* attention to securing it so that no
> stress can ever come on the panel joints. Use thin flexible wires, maybe
> 22-ga stranded. Double up if you need more current capacity rather than
> using a thicker wire. Practicing with a junk flex-circuit if you can
> would be very good - you need to tin the foil very quickly, tin the wire
> separately and generously, then apply it to the foil and quickly heat it
> to fuse the two. Gently scraping the foil shiny-bright will let it tin
> easily. The foil has practically no mass so it will heat very quickly,
> and if you're careful you won't damage the polyester backing too much or
> more likely cause the delicate copper foil to lift from the backing. Use
> something to glue the raw edge shut where you cut the ruined part off, so
> it won't tend to delaminate from there. Acetic-curing silicone RTV is not
> ok. A bead of hot glue could be great.
>
> Since there are 14 pins on the connector, DB15 would work fine too.
>
> Yrs,
> d
> ps - I've only had one delaminated flex-circuit to play with. I had
> partial success in relaying the wires and reactivating the adhesive
> holding the layers together, using an iron set on polyester. Spraying one
> side with 3M 88 spray adhesive might work better but I bet it would be
> absolute hell to get it assembled without disaster. Iron-on fabric repair
> scrim could be a much better choice. Regardless, this is finicky delicate
> work. Takes patience, calm, willingness to do the fixturing over and over
> until everything is right and stays put before putting the heat to it.
> Working progressively from one edge of a delaminated spot to the other,
> lining everything up with a rolling weight for 3/8 or half an inch, then
> coming behind with the iron to seal that much; rinse and repeat will be
> the method that works.
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