[RA1John]

What is the best method for cleaning older carbs?

Engine blocks get hot tanked, how are carbs cleaned/stripped prior to rebuilding?
Not just referring to getting the superficial gunk off but a good internal cleaning.

Thanks!

[Tom Vaught]

Because I know all of the circuits on a Holley carb or a Rochester 2-BBL carb and what the drill dimensions are I personally use a very fine media glass bead machine to totally get down to the zinc material and then have the parts dichromated (just like Rochester Products and Holley carburetor did brand new zinc castings.

Dick B still has dichromating done in Wisconsin and does very high quality work.

Tom V.

[Dick Boneske]

Yes, I use glass bead media and clean the zinc carb bodies in a blast cabinet. You need to remove crusted oil/varnish deposits first, since the media does not work well on that. If I want a shiny finish, I polish the bare metal with a fine rotary wire brush and /or Scotchbrite before dichromate.

The steel linkage parts need more aggressive blasting to remove rust & old plating. They need to be polished before plating or the finish is very dull.

The cast iron bases can be blasted fairly aggressively, also, but you need to be careful to not overdo it on the throttle bores. I always use a fine grit sanding drum to clean the throttle bores after coating the bases with Zinc Phosphate from Eastwood. The factory left the throttle plates bare steel--so they often rust badly. After blasting the plates, I have them plated black zinc, and always use DAG 213 to insure a good seal when the throttle plates are closed.

[topfuel67]

I would recommend using ppg dx533 to clean the carbs with a brass brush. Media blasting can be too harsh on these carbs unless you know what you're doing. Guys like Dick and Tom have their media blasting dialed in. Too coarse of a media or too much pressure will easily scar the soft zinc bodies.