Machining Powdercoated aluminium

[surfit]

We are going to powdercoat aluminium castings with CARDINAL P141-BK03 prior to machining to eliminate the cost of masking before powdercoat. Has anyone had any experience with this practice? What are the pro's and con's? This is an acrylic powdercoat. Is there going to be an issue with chipping or tool wear?
Thanks,

[Cmailco]

No, there will be no increased wear to the tooling. I've machined a number of powder-coated and hard anodized materials over the years with no discernible cost to tool life.

[Geof]

You might get chipping and my experience is that this depends both on how well the aluminum surface was prepared for the adhesion of the coating and on how aggressively you machine. Certainly try to avoid any up-cutting on a powdercoated edge as this tends to lift the coating off.

One idea I had but did not put into practice was to pre-chamfer all the powdercoated edges with a tiny carbide spot drill. This separates the powder coated area that will be machined away from the part that remains.

[surfit]

Originally Posted by Geof You might get chipping and my experience is that this depends both on how well the aluminum surface was prepared for the adhesion of the coating and on how aggressively you machine. Certainly try to avoid any up-cutting on a powdercoated edge as this tends to lift the coating off. One idea I had but did not put into practice was to pre-chamfer all the powdercoated edges with a tiny carbide spot drill. This separates the powder coated area that will be machined away from the part that remains.

I was thinking about chamfering first but I am going to give it a try without first and see what happens.