PVD experts please chime in

[ajoesmith]

As you may or may not know i m currently doing a Bell and Ross PVD project.

I have sent the bell and Ross BR03-92 to be PVDed by a company.

The rep i sent had the rep PVD, not real.

The company will micro blast, clean and then PVD.

What is the purpose of the micro blasting?

Im asking because the company is saying that is is very difficult to do the micro blasting, due to the very small parts.

I could send them the rep case in stainless steel, ask them to just clean and PVD, no micro blasting. I take it this would be ok?

My understanding or micro blasting is that it just prepares the surface to be PVDed.

IF its blasted with different grades of beads then the finish of the PVD will be slightly different - is this correct?

If it would be ok to send the SS case and eliminate the need for micro blasting then it would be easier. Not impossible but easier

Any help is appreciated

[Guest avitt]

I'm not a PVD expert, but I've learned a few things in my quest to find a PVD/DLC vendor.

Bead blasting before PVD treatment serves a couple of purposes: 1) It helps to clean the substrate (this is absolutely essential for proper adhesion of the coating) and 2) It gives a nice, even matte texture to the PVD finish.

In your case, the bead blasting is necessary to remove the rep "PVD" finish. Since you don't know what this finish actually is, it should be fully removed - taken down to the bare stainless steel.

I just had a case and bracelet professionally bead-blasted by a watch craftsman. He gave me the choice of media - either fine glass beads, or fine aluminum oxide. The aluminum oxide is more aggressive - it will "cut" the material more, and leave a matte finish. Glass beads will leave more of a satin finish. If you have them do the bead blasting, just tell them to keep it at or under 40 psi...There's not too much worry about overblasting stainless.

[ajoesmith]

OK so the micro blasting is essential before the PVD is applied

Right that clears that up

Thanks

[Guest avitt]

I don't really think it's essential...Cleaning the substrate is essential, and bead-blasting is one way of cleaning it.

[Watchmeister]

It depends on the finish you are trying to get. I don;t know the B&R but on a PAM PVD the glass bead blasting is critical to achieve that lustrous finish. Otherwise the coating appears completely flat (and too dark).

[Pix]

Interesting thread.

May I ask an additionnal question ?

What is the difference between rep PVD and "genuine" PVD ? I suppose there's a good reason that you have your B&R completely recoated.

Thx

[HauteHippie]

This will be interesting. Bead blasting alone probably won't remove the rep PVD cleanly.... Usually it would need to be stripped. Is this what they mean by "cleaning"?

[Guest avitt]

If the rep finish is actually PVD, then it might not be necessary to remove it. It is possible to recoat PVD (the coating will have performance that is inferior to one applied to a properly prepared substrate...but it is possible, and common practice in the tool industry).

If the rep finish is not PVD, but is som other type of coating, then all bets are off.

[ajoesmith]

I have no idea about the rep PVD but its looks just like black shiny paint.

Before i sent it off to the Company for micro blasting, cleaning and PVD, i got a 3M pad, you know the ones with the coarse green side and rubbed it gently and the black rep PVD came off easily.

Im sure the only way to go is to get the real PVD done.

Watch this space, very soon i will have it

[Guest avitt]

Before i sent it off to the Company for micro blasting, cleaning and PVD, i got a 3M pad, you know the ones with the coarse green side and rubbed it gently and the black rep PVD came off easily.

Wow, that's scary...and it certainly validates your efforts to get some real PVD on these babies.