Honda CB750 Sandcast

The Restoration Shop => Engine - Cosmetic Only => Topic started by: Riccardo on February 20, 2010, 03:02:56 pm

Title: cranckase, cylinder and head, finiture
Post by: Riccardo on February 20, 2010, 03:02:56 pm

 ???  The cranckase was natural from casting.
To restore it, is necessary use high pressure sicilicious sanding or other sand tipe, or chemical product to extract the original brilliance?
Where find the high temp. paint to remake the cylinder & headcylinder?
Thanks to all.

Title: Re: cranckase, cylinder and head, finiture
Post by: kp on February 20, 2010, 03:03:19 pm

media blast using plastic bead or some other soft media or better still, vapour blast. No paint required on a Sandcast engine KP

Title: Re: cranckase, cylinder and head, finiture
Post by: 736cc on February 20, 2010, 03:03:44 pm

I found the best way to really clean a sandcast motor is to remove it from frame (or at least strip as much as possible in the frame), plug the intake and exhaust ports w/ plastic milk bottle caps, then drown it in EZ-OFF oven cleaner (wear HD rubber gloves and eye protection), flip it upside down on a wood beer pallette, scrub w/ toothbrush, scotchbrite, hose it down, then etch it w/ hydroflouric acid (wire wheel/chrome cleaner). All engine covers will need refinishing (I like polished aluminum ceramic coated); the crankcases will now be super-sanitary.
These iconic motors should look tough and rough; not pretty.

(http://img356.imageshack.us/img356/5623/e1873aac5.jpg)