Cadillac & LaSalle Club Discussion Forum

Cadillac & LaSalle Club Forums => General Discussion => Topic started by: Titigros on October 26, 2016, 05:40:49 AM

Title: Zamak pieces restoration
Post by: Titigros on October 26, 2016, 05:40:49 AM
Hi, do you know how to restore well the Cad59 zamak pieces like these ones please? Two steel/chrome specialists told me they don't want to re-chrome this alliage as they cannot guarantee the immediate results, and even if they do it this would not stay long :-[. I have been told though the zamak pieces could be polished and then painted with a chrome-like color :o. There are many zamak parts in a Cad 1959, so this is a real problem if these pieces are in bad shape; to name a few : tail lights, upper headlight bezel, cigarette lighters, Inside/outside door handles, window handles, wiper arms base, outside mirror base etc. see picture
Thanks!
Thierry

Title: Re: Zamack pieces restoration
Post by: Scot Minesinger on October 26, 2016, 08:52:34 AM
"zamack", what is this?  The part pictured would require that the tail (with rubber section) attached would need to be removed to re-chrome it.  On cigarette lighters the back section should unscrew the sleeve and it comes apart.
Title: Re: Zamack pieces restoration
Post by: Steve Passmore on October 26, 2016, 09:34:05 AM
Zamack in the US is just Die-Cast or 'Pot metal'   Here its called 'Mazack' but its still the same old junk and many chromers don't like working with it.
I believe you do have some plating company's in your country that do specialize in it though.
Title: Re: Zamak pieces restoration
Post by: Titigros on October 28, 2016, 05:56:04 PM
Many thanks for your replies, in fact I found "zamak" (not with a c), an alliage of zinc, aluminium, magnesium, and kupfer (in German), so it's effectively a die-cast.  ;) I wanted to know if some members did use successfully some sort of polish + paint (and what kind of) instead of re-chrome which apparently is not feasible on this alliage if it's pitted, as according to chrome specialists I contacted "the pitting comes from deep underneath"  :( !
Title: Re: Zamak pieces restoration
Post by: The Tassie Devil(le) on October 28, 2016, 07:30:10 PM
The only way to re-finish these Diecast potmetal parts is to actually drill out the imperfections, and then carefully fill the now-clean cavities with Silver Solder.

BUT, there is no guarantee that the task will be successful as when heat is applied, there could be an underlying pocket of air nearby, and this will heat up and "explode" creating another area to fix.

The chroming of the original parts when new wasn't a problem, as every component part was stabilised, plus, the only parts that were being plated at that exact time, was the Diecast parts.

These days, when Platers chrome stuff, I believe that they just plate everything in the same vats and hope for the best.   Can't expect a brass part to take the same power requirements as a soft potmetal piece.

Bruce. >:D
Title: Re: Zamak pieces restoration
Post by: Steve Passmore on October 29, 2016, 03:30:48 AM
With pot metal the process is to apply layer upon layer of copper flatting the surface between layers eventually filling the holes. A very expensive process.     I have seen pot metal grills that were pitted dreadfully and chromed in the USA to perfection. On a 41 Buick I had in after a front end collision the grill was smashed the copper was the same thickness as the pot metal in places. The pot metal was smashed away from the rear leaving the mask of copper still standing and you could see the pot metal was like Swiss cheese. 
There are companies advertising in Hemmings Motor News that specialize in this stuff. Have you tried them?
Title: Re: Zamak pieces restoration
Post by: Classic on October 29, 2016, 10:14:58 AM
Jon Wright's Custom Chrome Plating in Grafton, Ohio does very high quality work.  http://www.customchromeplating.com/index.html (http://www.customchromeplating.com/index.html)  From their website:  "We work on steel, cast iron, stainless steel, brass, bronze, aluminum, copper and zinc die castings. We specialize in the repair and plating of difficult pot metal parts as well as damaged parts made of any of the above materials."
I have had pot metal work done by them and it was excellent.  I highly recommend them.  I realize you are in Europe, so perhaps Steve Passmore in the UK can recommend someone with similar capabilities closer to you.
Title: Re: Zamak pieces restoration
Post by: Steve Passmore on November 01, 2016, 07:20:27 PM
Sadly Gene I cannot.
Title: Re: Zamak pieces restoration
Post by: 76eldo on November 01, 2016, 10:16:59 PM
Thierry

I did answer your email about the AC parts.
Do you want to discuss these parts?
Thanks

Brian

Rachlin@comcast.net