Trying to achieve a "swirl-less" finish on epoxy

[honoluahomes]

I used colored/pigmented epoxy for signs and decorative art.  I was having some trouble with the old Dewalt RO sander I used especially with fine grade paper (say 400 grit and up).

So I took the plunge and got a Festool Rotext 150 believing that the integrated dust collection would help pull the sanded epoxy away from the work and not grind it into the epoxy like I was seeing with the Dewalt.

The Rotext & vacuum did alleviate the problem of the sanding the dust back into the work piece but the issue I'm having now is that I can't get anywhere close to the swirl-less finish I was looking for.  I purchased some Rubin 60-120 paper and in "aggressive" mode it does a pretty good job of evenly sanding the surface up with nothing in the way of distinct scratches or swirls.

As soon as I move over to the 220+ grit Granat (using RO mode) the paper just gums up and nothing but scratches and swirls.  In fact, it's far worse than even the big box Dewalt sander and paper (with the exception of not leaving behind a significant amount dust to grind back into the piece).  It has to be something I'm doing....wrong paper, wrong approach but I'm at a loss.

Any ideas, comments or suggestions would be appreciated!!

 

[Michael Kellough]

Turn the suction all the way down on the vac.
Reduce the speed of the sander.
Move the sander around quickly so the epoxy doesn't get too warm and gummy.

 

[peter halle]

Also might want to throw in a grit between your 120 and 220 and make sure you wipe between grit changes.  Last thing you need is coarse grit being swirled around on the finer pad.

Peter

 

[Holmz]

Is an epoxy a thermoplastic? or a thermoset?
More power and more heat will tend to soften the surface. A softened surface tends to gums up.

You may need to "do it wet"...  In which case a pneumatic sander could be better than a "PlugIt in a bucket".
but I am no expert in this so you need to check.

 

[bkharman]

Might want to also try the abranet screens from Mirka. The elimination of the actual holes might help any Corning that is happening.

Cheers. Bryan.

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