Honda CB750 Sandcast

Lacquer finish

Garry32

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Hi, Should  the engine covers and fork sliders be lacquered also linished or sisal finish.
Garry🇬🇧 :)


ashimotok0

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Hi, Should  the engine covers and fork sliders be lacquered also linished or sisal finish.
Garry🇬🇧 :)

I have just done 12 fork sliders for 6 of the  bikes I am restoring .. messy 'orrible job but quite rewarding in the end. IMHO the original finish is a 'satinized' brushed type finish then laquered. I used 1000 grade grit on the final finish to match a NOS CB350K fork slider I had. Any Methylene Chroride based paint stripper will take the old lacquer off literally in seconds ( well it did for the two types I tried out) Do it as quick as possible to avoid any damage to the alloy.

 I have not lacquered any of them yet but I have  got a spray can of 'Eastwood Diamond Clear Gloss for Bare Metal'. I think the alloy should really be pre-treated with something like Bonderite M-CR Alocrom 1000 to promote adhesion of the clear coat. I did find a UK source of it but it contains Hexavalent Chromic acid and Hydroflouric acid which are very nasty and the former is a known carcinogen. I have found a place in Leeds that will treat my parts as they have a production type setup but as yet no price or turnaround times. Evidently if you dip for too long you will lose the brightness of the finish, so it has to be well controlled but the Alocrom '1000' version is specifically for retaining the natural alloy finish.
I am pretty sure this is what Vic World must do  but I was not at the talk he gave on the subject in Ohio a few years back. Maybe Steve, ChrisR or others who did attend may throw some light on it.

I did ask MarkB what he pre-treated the alloy with and I think he just thoroughly cleaned with acetone after 'satin' finishing. Each fork leg took me a minimum of 2 hours to do.

If you scroll down to the end of  this 'MASSIVE' download in my Dropbox, there is a VJMC article reprint on the subject, which is quite informative. I spun the sliders in my lathe at 280 RPM and then finished the awkward bits manually. Watch your fingers !!! ;) I also de-greased in my ultrasonic cleaner

Pretty sure the covers are a similar finish with lacquering but not so sure that its a finer satinized finish than the fork sliders.

https://www.dropbox.com/s/anpzqn2r55f1o9k/CB750%20Mega%20Parts%20Service%20and%20More.pdf?dl=0

I think MarkB also posted a link to a guy on SOHC.net  forum, who has used powder coat clear with good results,  but it's a brave man who tries that out after spending absolutely ages, prepping the alloy as powder coat is a bitch to remove!

Hope this helps ...cheers Ash

Why not join us on sohc.co.uk too?
« Last Edit: July 11, 2016, 03:31:50 am by ashimotok0 »


Garry32

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Thank you Ash I have sent you a pm
Cheers Garry  :)