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Polish or engrave first?

2000

I intend to make a couple of front panels for my amplifier. They should ultimately be decorative chrome-plated, and there are also words to be engraved on the surface.

I have been advised by a plating shop that I should first cut the panels to size, then have them polished to mirror finish before drilling any holes or engraving, because according to this shop the polishing will take away all engraving and make the holes slightly oval at the edges.

The engraving shop however tells me that I should engrave first because there's going to be burrs after engraving that would need to be polished off anyway. Who's right here? Kik

Kik, Shian Jer
- Germany

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Dear Kik,

You want engrave the words on the surface of your panel. The engraving should be done after the polishing the part because the engraving letter has some height hence the reference plane should be parallel to the horizontal (0,0) and it can archive only with polishing.

We have done many engraving in our Injection mold (Made out of steel). If tool used for the engraving is proper then there in no chance of burr in the engraved letter. DRILLING OPERATION SHOULD BE DONE BEFORE POLISHING BECAUSE IN DRILLING PROCESS THERE MIGHT BE SOME BURR ON EDGES OF HOLE.THIS BURR CAN BE REMOVE BEFORE POLISHING THE PART. THE OVAL SHAPE CAN AVOIDED BY CONTROL PROCESS OF POLISHING ASK YOUR VENDOR TO TAKE CARE WHILE POLISHING THE PART.

Please let me know what your vendor say about my comments.

Thanks & regards

Bahadur Singh Rathore
- Udaipur, Raj., India
2000

Dear Bahadur, Thanks for your advice.

Due to problems in reproducing some of the intricate engravings, I have instead sourced for an old front panel that had been painted. The paint has been removed and the brass underneath looks in good condition. I will try to get this panel polished and you are right in saying that with care the holes should not be a problem. Hopefully after chroming the engraved letterings can still stay intact nonetheless.

Some of the shops agree with your idea of engraving after polishing, but they are also some who maintain that doing so provides the risk of scratching the polished surface. In any case I don't have a choice now. Regards, Kik

Kik, Shian Jer
- Germany
2000