A question for those of you who do resin casting

[STYRENE-SURFER]

Just wondering for those parts like valve covers, suspension parts, or anything that would need to be sprayed with Alclad chrome.

Would it be advantageous to cast them in black resin so you could skip applying a black base?

Maybe this has already been tried.

[Mark]

You might still have to apply the black base; it's probably needed to help the Alclad adhere to the parts.  Alclad alone might rub off with even light handling of the parts.  But you probably won't need as much of it on a part molded in black, and that would be a good thing...fewer coats, less likelihood of obscuring fine detail.

[STYRENE-SURFER]

I thought the key to Alclad was having a perfectly smooth black base.

Wouldn't a clean smooth BLACK resin part be the perfect scenario?

 

[Mark]

I've heard of people applying black lacquer as a base, and having problems with the Alclad rubbing off.  I'd suspect that they specify the enamel base to (in part) give the Alclad something to "bite into".  Resin alone wouldn't provide that.  There's nothing stopping experimentation, though... 

[STYRENE-SURFER]

Has anyone tried Alclad directly over black styrene ? 

I will do a test myself, I have have an old Lindberg gas tank cast in black and stripped of chrome.

Update soon.

 

[Ace-Garageguy]

I know for a fact that one of the reasons Alclad recommends a high-gloss black under their chrome is to get the reflection right. Flat-black won't cut it. Black styrene might have the right look if it's been polished, but as mentioned above, adhesion MAY be an issue.

In my experience, resin parts rarely come out of the mold or in the mail with a polished surface. The PVA mold-release or talcum power some casters insist on using imparts a slightly pebbly surface to the part, and that's gonna screw the chrome effect, even if Alclad will stick to it.

IF you make your molds from polished masters, and use a non-antique, professional mold-release, you CAN get the same level of polish on out-of-mold parts as the master had.

So if you cast them in black, and if adhesion over bare resin is an issue, you should only have to shoot one coat of whatever you choose to use as an Alclad undercoat.

Edited January 28, 2016 by Ace-Garageguy

[bill w]

First never use black for a chrome base. The best results I have is a gray base, 10 to 40 percent gray. Chrome dose not have color, it reflects whatever is around it.

I use a two part automotive urethane clear, wait 5 to 10 minutes and spray Alclad. The two part clear cures in twenty four hours and you can try rubbing the Alclad off

and it will not smear.