Epoxy bond surface finish parameters

[RedCoat999]

I am looking to increase the bond strength in a current application. Are there particular surface finish parameters that best define surfaces for good bonding? (we currently look only at a minimum Ra). We are using quartz as the blast media. Are there general guidelines for size/shape of the blast media that give the best bonding surface finish?
Thanks

 

[tomwalz]

Surface cleanliness - latest Metal Finishing magazine has a good article on this.

There are studies showing that blast media can facture into slivers and impregnate the material interfering with the bonding. The study I saw was done, I believe, with silica and tungsten carbide.

Tom

Thomas J. Walz
Carbide Processors, Inc.

http://www.carbideprocessor.com

 

[Riadsala]

Alumina particles work OK - use 60-80 mesh sized particles; aim for an anchor profile of 2mils (50 microns) average; ensure blast media is dry when used.
As a general rule for any blast media it should not be re-cycled (i.e. use it once only) as otherwise the surface finish will be compromised and inconsistent.

Riadsala