Brodhead Pietenpol Association

Original Posted By: "Gary McNeel, Jr."

Original Posted By: clif

Original Posted By: owner-pietenpol-list-server(at)matronics.com
I believe the correct term is "Engine Turning". It is the technique used onthe cowling of the Spirit of St. Louis, and is actually very easy to do. Imade a couple of inserts for my instrument panel this way:1. First I made a grid of squares on a piece of particle board. I mademine 1" squares, due to the size of "swirls" I wanted. I drilled a 1/8"hole at each intersection (the corners of the squares, where they touchedthe adjacent squares).2. Then I made a base plate to support the workpiece that I wanted toswirl. On the bottom of the base plate, I drilled two .121" holes 4" apartand pressed in a couple of small lengths of 1/8" welding rod. I made suremy base plate would fit anywhere on the grid board, and could be easilypicked up and repositioned.3. I then fastened my work piece down to the base plate. Since I wasmaking an insert to hold instruments, I made sure I was putting the screwsin locations that would be cut out for an instrument hole. If you aremaking a piece that is to be continuous, you will have to screw it downaround the edges and then trim off the area with the screw holes.4. Then I clamped the grid board onto the work support plate of my drillpress. I made my "swirler" from an old Continental exhaust valve with apiece of Scotchbrite superglued onto the face of the valve and trimmed tofit.5. I positioned the base plate with the workpiece screwed to it on the gridboard so that the swirler tool would start the pattern near one corner ofthe workpiece. Then I turned the drill press on and lowered the tool ontothe aluminum until ihad burnished a swirl pattern. You don't have to presstoo hard, and it only takes about one second to swirl each location. Then Iindexed the base plate one set of squares over and made another swirl. Thisis continued until you reach the end of the row, then you reposition thebase plate to begin the next row. In this manner, you can easily make niceuniform overlapping swirls. It took me severl hours to make the setup, andthen about 15 minutes to actually put the engine-turned pattern on myinstrument panel inserts.I have pictures of my setup, and would put them on the list but every timeI've tried to do that it gets screwed up. If anyone wants to see them letme know and I will email them to you.By the way, Pieters, I visited Mike Cuy last weekend and finally got to seehis airplane. Beautiful job! And what a nice fellow he is. We couldn'tpossibly have a better ambassador for the Pietenpol community.Jack -----Original Message-----

Original Posted By: "Michael Brusilow"
clif wrote:> > Some call it "swirling" others "burnishing" but I seem to> remember there was a better name back when I had> my 1st car, a 56 studebaker Hawk (no fins). It had this> neat swirled dash panel."Turned?" As in "engine turned?" Not much like whatyou do with a lathe, but that sounds awfully familiar.Owen Davies________________________________________________________________________________

Original Posted By: Gary McNeel, Jr.
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Original Posted By: "DJ Vegh"
This is an ancient procedure that probably dates back to thetime when craftsmen fashioned metal shields and armor.During the 1950's I apprenticed under an aircraft mechanic who had been in the business since the 1920's. He called thepattern "whirlies" and told me that, aside from being "pretty",it is an excellent means of covering scratches and minor form-ing marks without painting. He said its use should be restricted to non-structural parts.Lindbergh's Spirit of St. Louis used it on cowlings, etc. accord-ing to the custom of that period. No doubt he was happy with it because it didn't add any weight, as painting would have done.It was popular in the early days of aviation and is therefore most appropriate for Pietenpol airplanes. Graham Hansen (Pietenpol CF-AUN)________________________________________________________________________________

Original Posted By: "Dick and Marge Gillespie"
Subject: Re: Pietenpol-List: Swirly aluminium....Burnishing. Just cut a scotchbrite pad and glue it to the face of a small rotary sanding disc. The size is up to you. The swirls overlap. It is best to do your pattern before you cut it to shape Don Hicks________________________________________________________________________________

Original Posted By: DonanClara(at)aol.com
Subject: Re: Pietenpol-List: Swirly aluminium....In a message dated 5/31/02 9:53:12 PM Pacific Daylight Time, gmcneel(at)mykitplane.com writes:> I was wondering how some aluminium was made to have the little swirls on it> (I know it has a name, I cannot think of it).> > Once, long ago, I saw how it was done, but now cannot recall it. If any of> you know the name or where there is info on doing it, I would appreciate> hearing it. Thanks.> > Regards,> > Gary P. McNeel, Jr.> MyKitPlane.com> EAA 665957> Gary,Here's how I do the spot finish on many of my projects. This is shown on the Spirit of St Louis movie with Jimmy Stewart for just a few seconds during the aircraft production scenes.I use a 1 inch diameter wire brush from Ace Hardware (only one I could find),put the work piece on the drill press table, run the drill press spindle at slow speed, press lightly for each spot overlapping a little less than half of the previous spot. Continue making rows. No other tools are needed and it is very easy. Doug Bryant________________________________________________________________________________

Original Posted By:
Doug,After the swirling, do you use anything as a protectorant to guard againstcorrosion?DickG. in Ft. Myers----- Original Message -----

Original Posted By: Larry Neal

Original Posted By: DonanClara(at)aol.com
Subject: Re: Pietenpol-List: Swirly aluminium....In a message dated 6/2/02 5:14:08 AM Pacific Daylight Time, dickmarg(at)peganet.com writes:> Doug,> After the swirling, do you use anything as a protectorant to guard against> corrosion?> > DickG. in Ft. Myers> Hi Dick,Good to hear from you. I don't use any form of corrosion protection here in Kansas, but I suppose a clear alodine could be applied. Doug Bryant________________________________________________________________________________

Original Posted By: "Gary McNeel, Jr."
Subject: Re: Pietenpol-List: Swirly aluminium....In a message dated 06/01/2002 2:15:57 PM Central Daylight Time, grhans@cable-lynx.net writes:>The amphibion Fleetwing Seabird in the late thirties used burnishing over most of the stainless steel hull skins to cover irregularities. Quite an eye-catcher. Two are still flying in Calif. and Florida. ________________________________________________________________________________Date: Sun, 02 Jun 2002 16:54:16 -0500

Original Posted By:
EVERYTHING has to be protected here in Florida. One of the prices to payfor living in "Paradise". Couldn't a clear coat or clear lacquer orsomething like that be sprayed on?Ted B in Naples----- Original Message -----

Original Posted By: "Ted Brousseau"
Spar varnish (or equal) was used on the nose of the Spirit of St. Louisswirls -- as a result, there is a "golden" hue to the Alum. as it sits inNASM.Also, the "quick & dirty" way (used by Fokker in WW1) was to just "sand" thecowl all over with a grinder or dual action sander (no nice rows -- justrandom stuff! ;-)Mike C.Pretty Prairie, KS----- Original Message -----

Original Posted By: raymond smith

Original Posted By: Michael Conkling
I always understood that the purpose for the "burnishing" or "machining" or"machine turned" swirls was that the grooves would hold oil and preventcorrosion, so if you spray some light oil on and wipe it off it shouldprotect. I would think that the Spirit was probably varnished at some laterdate as an attempt at preservation, but I do not know if that is the case.Gene----- Original Message -----