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Permalink Reply by Joe Harrington on October 14, 2012 at 7:55pm

I have spent about 12 more hours polishing since my last post here. I am learning a little as I go and I am getting a little more efficient. I have polished the top and bottom of the fuselage and am now working on the left side of the fuselage. Because most won't see the bottom and top, I made two passes with Nuvite F9 and one with Grade "C". They look okay but are not great. The quality of finish on the sides of the fuselage will be for all to see, so I am spending more time on them. So far, I have made 2 passes with F9 and 2 passes with F7. It looks okay but definitely needs more work. I am not sure if I am going to do more "heavy" polishing with F9/F7 or if I am going to go now to Grade C. BTW, I really could not see any real difference between F9 and F7.

For technique, I have tried running the polisher faster and slower, more and less pressure, more and less polish, polishing across and with the grain. For me, running the polisher slower (300 rpm) with a fair bit of pressure while using more polish than the available information says to use, seems to work best. There are so many variables and am like some, and I am becoming almost superstitious in my methods. I recently have been experimenting with first polishing across grain in one direction, then across grain the other (180 degrees), then both directions with the grain. This seems to bring a little better shine quicker. Even though slow polisher speed seems to work best for me, I have tried upping the speed to 1500 rpm. I have to move the polisher much faster to avoid heat build up, so I am able to cover more ground this way. It just seems like it does not shine quite as much with the same number of passes. 

I will report again when I have a little more experience. In the mean time, here are a couple more pictures.

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Permalink Reply by Ken Ryan on October 14, 2012 at 9:59pm

Thanks for your insights.

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Permalink Reply by Rick George on October 14, 2012 at 10:05pm

Wow - Looks great!!  Thanks for the report.

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Permalink Reply by Joe Harrington on October 27, 2012 at 10:27pm

OK, so I am continuing to learn and progress. Basically the more passes, the nicer the finish. I finished the right side of my fuselage to the point that I would be willing to fly it like that. I made 2 passes with F9, 1 pass with F7, 2 passes with C and then I bought the "Cyclo" random orbit dual head polisher and made 1 Cyclo pass with C and the finished with 1 cyclo pass with S. It is pretty shiny now. Sorry, I don't have a photo because I am in my dark and dingey (and now very dirty..!..) garage. I will try to get a picture posted here soon.

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Permalink Reply by Joe Harrington on November 12, 2012 at 10:23pm

Here is a couple of pics of my polished fuselage. Hard to get good photos.

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Permalink Reply by Louis W. Ott on November 19, 2012 at 12:12am

Hi Joe,

I've begun polishing my 601XL-B. I'm generally following the polishing instructions found on the Sonex web site referenced in an earlier post. I also have the Makita variable speed polisher and, like you, found that a slower buffer RPM works better. It has less tendency to cook the Nuvite and leave that impenetrable black coating. I really like the variable speed setting wheel to set maximum RPM plus the variable speed switch. The soft start is nice too. Since my plane is done except the wings are off right now I have some corners, and junctions where the big buffing wheel just won't fit. I'm going to look for a small buffer maybe around 3" or 4" to use in those places. I could do it by hand, but the rotary motion is better to not leave noticeable scratches. One thing to add is to not scrimp on the passes with F9 to take out all the mill marks. Otherwise you get nice shiny mill marks where they show up the most.

It leaves a black coating on the floor so use a drop cloth. I didn't notice the floor until I was finished with this step. Here is a couple of pictures with two passes of F9 (should have been 3 passes) and two passes of C.

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Permalink Reply by Joe Harrington on November 19, 2012 at 1:45pm

Hi Louis,

Yes, smoothing out the mill finish first is the key to getting a nice finish. For some reason that I haven't determined, the mill finish was easier to knock down in some areas that others. Not sure if it is my inconsistent polishing methods or if there is some inconsistency in the aluminum sheet properties. Did you notice this at all?

I also have alternated between using F9 and F7 and can not see any real differences in finish or time to polish.

BTW, your 601 looks great!

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Permalink Reply by Louis W. Ott on November 19, 2012 at 9:34pm

Hi Joe,

I worked on the bottom of the wings today. They are in a cradle so they are near vertical and not having to lay on my back. One striking difference in taking away the mill marks is the structure underneath. Where there is a simple angle stiffener, upright, rib, or anything supporting the aluminum the mill marks come right off. In between on unsupported Aluminum sheet, it is very time consuming with many passes needed. I think Nuvite needs F12 or 15 to get the surface smoothed out.

I also trailered the fuselage to the airport this morning so it's been a full day.

It's been within a week of three years ago that I brought the airplane home in big crates.

Here is a picture with the fuselage on the trailer this morning and another in the hangar lit by one small bulb after dark when I finished this evening.

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Permalink Reply by Mack P. Kreizenbeck on November 25, 2012 at 7:11pm

This is 4-5 passes with Nuvite F-9. You can see where I stopped. I use Harbor Freight polisher at low speeds. I do not get the same results that you guys have. What am I doing wrong?

Mack

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Permalink Reply by Joe Harrington on November 25, 2012 at 9:31pm

Hi Mack,

4 or 5 passes? I am not sure what, if anything, you are doing wrong... Because our descriptions are very subjective, you just have to experiment until you come up with a method that is acceptable to you. Getting the correct amount of polish product, I believe, is important to match your method. I find that too little and it doesn't polish and too much and it just "lubricates) (feels greasy) which also results in poor polishing. I find the right amount of polish coupled with the right speed, the correct angle of the pad, the correct pressure (quite a lot) and it wants to pull the polisher out of my grip. This is when I get the most effective polishing. When I first started, I borrowed my friends polisher equivalent to the Harbour Freight polisher and I found that I could not put enough pressure on it or it would stall. If I bumped up the amperage, it would just spin wildly when I inevitably let up on the pressure and it flung polish all over the place. I think buying a good polisher (eg Makita, DeWalt, etc) is a worthwhile investment. It is also important to keep the pad fluffed up. Once the pads get matted, they drastically lose their effectiveness. I have washed my pads several times so far. I have bought 6 pads so far and am soon going to buy more. 

Also, you might try going to Grade C. With F9 or F7 it will not get near as shiny as the finer grades get. You might want to try a small area and see if that starts to give you some results you are looking for. Sorry I don't have any better suggestions. Good Luck!

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Permalink Reply by John Clark on November 18, 2012 at 9:39pm

Underside of right wing.. I'm polishing the skins first to Nuvite grade C, then I might do a final coat of grade C then S before final assembly to the airplane. Polishing with the heavy polish over rivets bothers me.. I am worried that it might be degrading their strength. At this point, I am planning on polishing all exterior aluminum on the airplane. I am much better at this than painting (or even choosing a color)

Sorry about my ugly ceiling with wires running about.. darn that shine!

--John

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Permalink Reply by Joe Harrington on November 19, 2012 at 1:55pm

Hi John,

I really don't think that polishing will hurt the rivets at all. I read somewhere that Boeing tested for material removal and found there was very little, if any. If I remember correctly, the test samples were polished repeatedly (something like 40 passes) and the alclad was still intact. Alclad is very thin; measured in the microns. This type of polishing apparently just "moves" the surface around.

I am polishing for the same reason as you; I HATE painting! So far, if I were to do it again, I would still polish.

Keep at it.

Joe

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