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This tape will self destruct ... any alternatives?

I electroform Nickel Cobalt and Nickel forms from 18/8 stainless mandrels. I use acid resistant tape to mark the trim line, which has to be repaired/replaced every time an electroform is removed. This is time consuming. I now have a job which requires 3 times faster turnaround, so can anyone help regarding any type of permanent/semi permanent coating which can be applied to the mandrel which will act as the present tape does, but which requires no maintenance/retapes/repairing breaks, etc. I have been told there is a "ceramic?" coating, and a "rubberised"? coating, but I am in the dark here! The bath is at 65 °C with air agitation, immersion time up to 24 hours, All suggestions are very gratefully received.

Gary Batty
Doncasters Bramah - Sheffield, South Yorkshire, UK
 

More information is required. Ceramic and epoxy coatings can likely do the job you want, but application may be a problem. We use an epoxy dielectric to mask 304 stainless, but the mandrels are cured at 500 °F for one hour after the epoxy is applied. I believe ceramics require curing as well. I guess what I'm saying is that any other method will probably require extra steps compared to the tape you use now.

Don Piett
- Thompson, Manitoba, Canada
 

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Just a thought but blasting companies are trying to sell to us a rubber like coating such as you find on the nozzle of a grit blast gun as a maskant.

They might be able to put a band of this around your electroform to act as a mask as the tape does.

Martin Trigg-Hogarth
surface treatment shop - Stroud, Glos, England