Petrzelka #4 - Flamed Maple and Sitka 00-12

[Daniel P]

I've started thinning the sides for this build. First several passes through the newly acquired Preforamx 10-20 to get them down to about .090 - then on to hand scraping as I take them down toward .080"

Figured maple really wants to burn with 80 grit in the drum sander - still working out feed rate vs depth of sanding. I went back to the 36grit in the first few passes and ran the feed at 100 - seemed to work best at a higher rate of feed. Slower feed rates, with 80 grit, and even the lightest past wanted to start turning brown.

So much to learn.

[Bob Dill]

Try running your maple a second time at the same setting, most of the burning should be eliminated. I've used this method on several flame and quilted maple sets and it worked for me. I'm running it thru a 80 to 120 grit double drum sander, coarser grits leave deep grooves which are hard to remove.

[ken cierp]

The only abrasive we have used that does not cause hardwood burn is this

http://www.woodworkingshop.com/product/pe40280/


I think the Zirconia particles have edges that stay sharp and don't clog -- if the feed speed is too slow you'll also have issues. Thicknessing with finer grits is well -- a waste of time. The tool is after all a thickness sander not a finish sander.

[Daniel P]

Thanks for the link Ken.
Is 80 your preferred thicknessing grit?

[ken cierp]

Yes -- smoothing with a RO and 120G is a snap.

[Daniel P]

I took the sides down to about .085" and decided to go for it with the side bender.

I set my controller to go to 300 degrees and hold - I started the bending as the temp hit 280, finished within a few minutes, and then let it soak at 300 degree for about 5 minutes. Cooled it to room temperature, and then did another cycle to 280 degrees for 6 minutes.

The first set had just a slight cupping, likely due to a little too much water - the second set I misted more lightly with water and it came out quite flat. I'll be using wood side reinforcing strips, so the cupping should be easy to flatten.

No cracks, crumples or scorching - I'll call it a success.

[Daniel P]

They fit the mold nicely.

Another great example of the versatility of the KMG mega mold. A couple days ago I had this set up with the 00-12 template, and used the contour bar to make side patterns for this build, as Ken outlines here:

http://www.kennethmichaelguitars.com/si ... lates.html

It then only took a few minutes to set it up with a Ditson 12 fret template to hold a body for routing binding channels, and then back to a 00-12 to complete this build.