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 Sailplane Construction Project Session #148

Comet Sailplane Project
You know that sick feeling that comes in your stomach when you sudden realize something has gone wrong! After looking at the hand brushed on flat black Acrylic shown below on the fuselage for a while that I selected for the trim, I became painfully aware that it was too flat! In fact is was so flat that in the light it looked almost smoky gray %$#&@! Of course the question was, what can be about it.
A decision was made to stop and conduct a test to see what the possibilities were for bringing out more of the sheen in the flat black Acrylic. My test findings are reported below.
 Pictured below is the test sample with the three black Acrylic paint strips that were made up. The approach was to first air brush glossy Klass Kote over the (2) Flat Black strip on the right and compare it with Flat Black (1) strip in the center. Then air brush satin Klass Kote over all three strips and see how they compare.
Test A
Result (1): The glossy Klass Kote air brushed over the (2) Flat Black strip on the right made the finish actually quite glossy as you can see. You can even kind of see my facial reflection in the strip. 
Test B
Result (2): The satin Klass Kote was air brushed over the entire test sample, which covered all three test strips. It is a little hard to see in the picture, but the finish on the semi gloss and flat back without the coat of glossy Klass Kote are exactly the same.
Test C
Result (3): Comparing the finish on the (2) Flat Black strip with satin Klass Kote over the coat of glossy Klass Kote, it may have a slight more sheen and be slightly smoother than the other two test strips. However, the word "slight" is ever so slight as there is actually hardly any difference. The satin Klass Kote on the test samples was allowed to cure overnight and was examined again the next morning. It was concluded that the glossy Klass Kote made no difference at all.
A painting mandrel for the Sailplane's cowl shown below was made so there would be a stem of mandrel to hold on to while the satin Klass Kote was air brushed on the cowl.
This is a close up picture was taken of the cowl as a reference for comparison to show just how really flat the flat black Acrylic paint came out when it was brushed on the cowl. The finish borders on being terrible in that it looks a lot like charcoal. Also, if you look close you can see the brush marks left by the second coat of flat black Acrylic paint.
Using the 1500 grit, I carefully (but thoroughly) wet sanded over all of the flat black Acrylic on the cowl. I went over it twice and never did sanded through to the orange silk. :O) Then I mixed up 1-part clear and 1-part satin catalyst and let it set for 45 minutes. Then I mixed in 1-1/2-parts reducer and stirred the mix up well. Finally I airbrushed the entire cowl with a single coat of satin Klass Kote. As you can see below, the doped orange silk and the sanded flat black Acrylic both came out with a beautiful matte satin finish that is completely homogenous in both texture and sheen. Wet sanding with the 1500 paper got rid of almost all of the brush marks in the black Acrylic and the satin Klass Kote filled in the rest. 
 I could not be more pleased.....excited is more like it!.............................Tandy

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