Festool Fine Grits - Am I Understanding This Correctly?

[Bill Adamsen]

This should perhaps go to the finishing forum.

For spray lacquer finishes which - depending on customer requirements - I might flatten with progressive wet sandpaper followed by polishing and even wax. I would start with 400, 500 or 600 grit and progress typically to 2000 (Norton Black Ice) grit. Recently I "drank the coolaid" and bought into the Festool system, primarily to control dust on coarser grit wood/plastic sanding, but also because of it's flexibility with polishing. I was "caught on my heels" to discover (only after the fact) that the Festool grits seem to deviate significantly in the higher grit ranges (see image below).

Is this correct? Here is where I got into trouble ... I'd wet sanded to 800 grit and then used the Platin 1000 ... turns out to have been a major step backwards. No one at the Festool retail store brought this to my attention ... my own "mea culpa" for not reading the fine print.

Page 3
http://www.festoolusa.com/Web_files/Getting_the_most_from_Festool_sanders.pdf

[Bill Adamsen]

Turns out George Salerno has a good tutorial on just this topic, for which I somehow "missed the memo."

http://www.arcair.com/arcarm/tnt1/101-200/tnt134-sandpaper-Salerno/00.shtm

[Brian Tymchak]

Nice chart! That's going in the shop.

Thanks for posting!

[Mike Heidrick]

I don't wet sand pre cat. I break the surface and spay the next coat. The sand up on final layer.

[Bill McNiel]

As I understand it, the European "P" grading standard is much more restrictive than the US. The CAMI allows a greater percentage of not to spec grits to exist in a single sheet of paper where the FEPA is significantly more restrictive as to actual grit sizes and therefore more accurate. It works for me.

[David Nelson1]

That is some good gouge Bill!

[Andrew Pitonyak]

324308

I have been maintaining a "grit" chart for some years now. It is difficult since a "grit" is generally based on a percentage in a certain size range. We will see if the attached XLS file works. It refused the ODF file (sadly).

[Bill Adamsen]

Update ... used the 4000 Platin, followed by the 8000 polish via a felt pad, and I'm actually pleased by the results. They should be readily reproducable. The finish was a Satin Lacquer though it may be too lustrous for the job architect. We'll see. This is just a sample to illustrate the fit, finish and glass. Any thoughts on how to cut the lustre if the client objects?

Bill McNiel ... while I too am satisfied ... it just would have been nice if when I purchased the equipment and the $280 worth of fine grit sandpaper someone had been knowledgeable enough to say, "the grit may not align with your expectations for grit ... and may not work interchangeably with the grit of another supplier."

I now know that Festool uses the European "FEPA P" system, but nowhere on that box is that mentioned.

[Bill Adamsen]

324308

I have been maintaining a "grit" chart for some years now. It is difficult since a "grit" is generally based on a percentage in a certain size range. We will see if the attached XLS file works. It refused the ODF file (sadly).

Thanks Andrew ... this downloaded fine and is very helpful

[Andrew Pitonyak]

Good.... The data is acquired from numerous sources...

[peter gagliardi]

The P system has been in use here by 3m, and others I believe for at least the last 15 years. I have not had to correlate US to European systems since back then. Until I tried sponge backed paper like the Mirka goldflex, or Indasa Rhinosoft, I would use the spent discs for hand sanding, wrapping them around cotton rag to conform to odd shapes.
In the shop, we have for years sanded to 320/400 on everything, but you get into trouble with that on stain grade work.
I have never had an issue with spray applied finishes at that level coming out like glass , minus a dust spec occasionally.
Unless someone does a poor job with successive grit sanding, you need waaaay above average eyes to be able to try to see a scratch pattern.

[Bill McNiel]

Mahalo Andrew - your "grit" chart is most appreciated and unbelievably comprehensive. It is already stored on my desktop and soon to be printed, laminated and posted in several areas of my shop.

Thanks again

[Bill McNiel]

Bill Adamsen- first off - NICE WORK! You can "adjust" the finish luster with MicroMesh. It comes in about 9 grits and is a really simple way to rub out most finishes to a desired sheen (IMHO).

As far as paper by & for Festool toys I pretty much use Granat now. Klingspor offers a very competitive paper at a significantly lower cost that has the Festool 9 hole pattern. BTW-It is rated on the P scale (I checked this with them a couple of years ago).

[mreza Salav]

I gave up on Festool sand papers very soon after I tried a batch of them. You can find other brands that have the same hole pattern. For 3M is not bad value (inexpensive). Abranet is expensive but pretty good.