Topic: Door striker and latches

[CCP]

 Just a quick question guys. Working on a '70 XR7. What is the correct finish for the door strikers and latches? Is it silver cadmium, or the zinc dichromate?
   
           Thanks, Pete.

[Bob Gaines]

Just a quick question guys. Working on a '70 XR7. What is the correct finish for the door strikers and latches? Is it silver cadmium, or the zinc dichromate?
   
           Thanks, Pete.

Sticekers are typically silver with the spacers underneath being zinc dichromate . The latches are mostly silver with smaller components of zinc dichromate.

[CCP]

  Thanks. I ordered some new latches from NPD and they came in the zinc dichromate. Was just curious.

[Bob Gaines]

  Thanks. I ordered some new latches from NPD and they came in the zinc dichromate. Was just curious.

The short answer is the zinc dichromate will come off when exposed to a mild acid like what you find in chrome and wire wheel cleaner. Under the zinc dichromate is zinc silver which is left when the gold is removed. There has to be a base of zinc for the chromate to stick to.

[CCP]

  Just getting into replacing these door latches and noticed that the old ones are slightly different than the new ones from NPD. It doesn't mention anything in their catalog. This car has power door locks and it looks like the latches have some sort of contact soldered to the latch. Haven't gotten them out yet so I can't do a good side by side comparison. Is there a difference between power and non power? Anybody ever run into this?

                  Thanks,  Pete.

[J_Speegle]

  Just getting into replacing these door latches and noticed that the old ones are slightly different than the new ones from NPD. It doesn't mention anything in their catalog. This car has power door locks and it looks like the latches have some sort of contact soldered to the latch. Haven't gotten them out yet so I can't do a good side by side comparison. Is there a difference between power and non power? Anybody ever run into this?

Power door locks?  Sounds like a previous owner has modified a thing or to

Maybe the owner modified them (I've done that before" or got something out of a different car and made it work.

[CCP]

  My mistake. There is a contact on the inside of the door latch mechanism with a wire that leads to the power window switch. All the switch on the door panel says is "lock", hence my confusion. I'm still not sure what the purpose of this contact and wire is. When the door is latched, this contact is broken (open). I'm confused. Does this somehow relate to the power windows?

[0F94M]

The switch on the door latch is for the door ajar light.

[CCP]

   THANK YOU!!! You guys are amazing! The help, as usual, is very much appreciated. 

[CCP]

  The new latches from NPD were slightly different where the contact for the 'door ajar' switch is mounted. After a little alteration the switch is installed and the door ajar lamp works as intended.
  Thanks again for the help.

                        Pete.

[Bossbill]

The short answer is the zinc dichromate will come off when exposed to a mild acid like what you find in chrome and wire wheel cleaner. Under the zinc dichromate is zinc silver which is left when the gold is removed. There has to be a base of zinc for the chromate to stick to.

On another forum my naivete on plating showed up when discussing another zinc dichromate part.
It appears even interior parts can suffer from environmental issues that degrade the gold chromate.
So while the threads of my bolt showed zinc dichromate, the head of the bolt was dull zinc. To further confuse things when you remove the bolt it removes the dull zinc and the shiny zinc underneath shows through.

I'm looking at Caswell Plating kits for both the CopyCad and their yellow chromate application.
https://www.caswellplating.com/electroplating-anodizing/zinc-plating-kits/chromates/yellow-chromate.html 

[Bob Gaines]

On another forum my naivete on plating showed up when discussing another zinc dichromate part.
It appears even interior parts can suffer from environmental issues that degrade the gold chromate.
So while the threads of my bolt showed zinc dichromate, the head of the bolt was dull zinc. To further confuse things when you remove the bolt it removes the dull zinc and the shiny zinc underneath shows through.

I'm looking at Caswell Plating kits for both the CopyCad and their yellow chromate application.
https://www.caswellplating.com/electroplating-anodizing/zinc-plating-kits/chromates/yellow-chromate.html

The chromate is very carcinogenic so you need to have proper ventilation and wear a good filter mask.Also there is a learning curve.

[Chris Thauberger]

On another forum my naivete on plating showed up when discussing another zinc dichromate part.
It appears even interior parts can suffer from environmental issues that degrade the gold chromate.
So while the threads of my bolt showed zinc dichromate, the head of the bolt was dull zinc. To further confuse things when you remove the bolt it removes the dull zinc and the shiny zinc underneath shows through.

I'm looking at Caswell Plating kits for both the CopyCad and their yellow chromate application.
https://www.caswellplating.com/electroplating-anodizing/zinc-plating-kits/chromates/yellow-chromate.html

A good choice. I purchased the same kit and after some experimenting I was able to achieve excellent results.

Bob is correct the Chromic acid is toxic and appropriate PPE as well as a ventilation system should be used. I can provide some guidance there if you elect to pursue this avenue.


After zinc plating a part it is rinsed in hydrochloric acid briefly to etch the new surface to receive the chromic acid layer. Agitating the part in the chromic acid for 20 -30 seconds creates what is known as a "conversion layer" on the fresh zinc.

I thought I posted a few pic on this site but it could have been the old SAAC Forum.

Chris

[Bossbill]

Chris T. -- Perhaps a new thread on how you did this? Jim started me going on Phosphate and Oil with his threads there, so this would be very useful. Cooking up that stuff requires good ventilation as well.

[jwc66k]

Jim started me going on Phosphate and Oil with his threads there, so this would be very useful.

I'll tell you my little secret - I have a local professional shop do my clear and gold zinc plating. We have an "arrangement". That "arrangement" includes me providing the shop with clean, bead blasted parts untouched by human hands (I use gloves), a minimum lot size order (75 pieces), no "due by" date (it's usually 4 to 6 weeks, my stuff is fitted in the shop's schedule) and no arguing. There's other "things" in the mix. I operated in bulk to get minimum lot sizes, I did have four cars most of the time, 65 and 66, so I got ahead of myself. Gold zinc was the most difficult to get minimum lot sizes as those years didn't have a lot of that type finish.
Bottom line - real good zinc plating needs techniques that are expensive and dangerous. There are a few members here that I have supplied with zinc plated parts using my method. I've received no complaints.
Jim