I used to do this test but not on an assembly. I used to puddle the 
suspected area on the board with reagent grade IPA for a few minutes. 
Depending on the area and quantity of liquid, I transferred it to a 
filter paper, either by tipping or with an eye dropper. After all the 
alcohol had evaporated, I did the Raspail 1 test as on p.24 of Bev's 
link. You have to be very quick as the pink colouration is very thin and 
ephemeral at the edge of the burnt area produced by the acid. I was 
under the impression that I had described this in my book, but I 
couldn't find it!

Brian

On 24/05/2012 03:18, Bev Christian wrote:
> Rich,
> Check this out.
> http://cool.conservation-us.org/coolaic/sg/bpg/pcc/10_spot-tests.pdf
>
>
> Section 10, Page 24 Spot Tests.  The reference at this point is Barrow 1969,
> 13, TAPPI T408. I did not follow this up.
>
> I have never used the test myself.
>
> Bev
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Richard Kraszewski
> Sent: Wednesday, May 23, 2012 6:28 PM
> To: [log in to unmask]
> Subject: [TN] Spot test for Rosin Residue
>
> I seem to recall a wet chemical spot test for rosin residues.
>
> Something that required:
>
> 	* Piece of filter paper.
> 	* Sugar solution .
> 	* Dilute Sulfuric acid.
>
> If the final spot went red, it would indicate the presence of rosin.
>
> Does anybody recall this test and have the details?
>
> Thanks in advance
>
> Rich� Kraszewski
> Plexus Engineering Solutions
> �
>
>
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