I saw the bottle he uses.



He had some of these exact bottles… ones labeled ACE / H20 / FLUX

http://www.ebay.com/itm/Solder-Soldering-Flux-Syringe-Funnel-Empty-Plastic-Bottle-50ml-/120857576741?pt=LH_DefaultDomain_0&hash=item1c23ac4525

i didn't ask how he applies the ACE,

I think he just uses that bottle / needle, and runs some in the seam and then starts beating right on the seam all the way around.

i didn't expect him to disclose all his secrets to me (in one sitting)