War Paint on the Rudder

After a long few days of prep and paint, the rudder is finally covered in war paint.  The rudder on the left is mine, and the one on the right is on a flying Sopwith.  The paint took a few days because between each coat of each color I had to let it dry.  I would work fifteen minutes at a time towards the end.

 

I did the white stripe first, figuring that would be the easiest to cover if there was a mistake.  I set up a makeshift paint booth in my garage and used the spray gun for the first coat.

 

 

 

Overall, I wasn't too happy with the spray gun, so I switched to rollers. Several other builders rolled their paint on aircraft that are flying and have no issues, and rolling takes about 1/10th as much time in cleaning and prep, so that seems to be the way to go.   I used simple 4" high density foam rollers from the aviation department at Lowe's, the same place I picked up the paint.  Side rant:  When did paint get so bloody expensive?  Seems like it has tripled since the last time I painted...

 

Here is the white stripe after the second coat and the masking tape was pulled.  One thing I noticed was there was some bleed that I didn't like.  I think the spray gun was part of the problem. For the next two rolled colors I had much more success, but I also made sure to keep the tape lines at the top as I painted to allow gravity to help, so that might have been the major factor in the better lines.

 

 

Coat one of the red paint for the tip. hanging the rudder so I could rotate it to get at the edges was a big help.

 

 

Second coat of red and, when the tape was pulled, I was much happier with the line. 

 

 

Next, the first coat of blue.  I had to use a brush to get all the nooks and crannies on this stripe, particularly around the control horn.

 

 

Using a pile of shop towels and a clamp I then hung the rudder to dry so that the blue paint would be pulled away from the paint line.

 

 

The second coat of blue, then the tape was pulled to reveal the final product.

 

Tomorrow, spraying two clear coats over the rudder and she is all done.

 

 

Practice Build Time = 5.5 Hours

 

Final Fabric Shrink and Primer

It's looking good!  As the rudder is almost ready for paint I am pleasantly surprised with the results at this point.

First thing before the final heat shrink of the fabric, I picked up a basic full-size iron from Target.  The small hobby iron I had worked great for small lines, curves, and tape, but it would loose heat quickly and was very lightweight.  This one worked great, held heat well, and had a bit of weight to let the iron do the work when shrinking.  I used my infrared thermometer to get exact dial points for 250, 300, and 350 degrees (the white paint marks on the dial).  The iron worked well and held its temperature within +-4 degrees.  I looked a while for an iron without auto shutoff, but it wasn't a problem with this one.  It had a red light that would flash when in auto shutoff mode, so you will see it and know the iron needs to heat up again.  Plus, it only took about 60 seconds from cold to full heat.

 



I started with the iron at 250, working the tapes and seams in an alternating pattern to avoid distortion while the fabric shrinks.  Then, I worked the open fabric in the same manner, letting the weight of the iron do the work as it slowly slid along.  The results were positive with wrinkles shrinking up, glue bonding stronger, and the fabric tightening up.  After a cooling period, I repeated the process with the iron at 300, then after another cooling period did it all again for the final shrink at 350.  The tightness of the finished fabric turned out very strong.

Finally time for paint!  The primer process using Stewart Systems EkoFill uses three coats applied in a certain manner as a primer and UV blocker. The first coat and the second coat are applied in opposing directions.  I put the first coat on with a foam brush from front to back, taking care to use even strokes and getting a good full coverage.

Once the first coat was dry, I lightly ran over the surface with a 320 grit sanding sponge to try and take out any minor bumps and imperfections.

 

 

Then, the second coat of primer.  This one using a foam brush as well, but applied in the opposite direction.

 

Tomorrow, once it is dry, I'm going to apply the third primer coat with the spray gun, then it will be time to paint and finish this thing.

 

Practice Build Time = 2 Hours

Finishing Tape

Now that the fabric has set, it's time for the finishing tape.  I cut out 2" strips of fabric to use as tape for the rib seams with the pinker after tracing out the strips with a pencil.  I figured for this practice rudder there was no need to order a roll of tape and the spare fabric could get me by.  They turned out nice and straight with clean pinked edges.

 

A quick sizing and pinking the edges for a precise fit and they are ready to glue down.

Per the suggestion of the fabric system manufacturer, I started by gluing about a two inch square on the wing fabric, then placing the leading edge of the strip over the glue patch while wet.  I pressed in the strip, then brushed glue on top.  While wet, I wiped the glue with a shop towel to help press in the glue and to clean off any glue ridges that would show through finish.  I repeated for the rest of the rib tape strips, then let dry.  This gave a good base to work with that allowed be to tug the strip straight as I worked it later.

Once the tip was dry, I finished the tape with the same process as the initial spot.

I let that dry, then worked the other side of the rudder  in the same manner.

Next was the finishing tape for the rudder bow.  I use 3" Bias Dacron tape for the bow because I wanted something that could stretch out the wrinkles around the curve.  Turns out that was a good choice.  I started by tracing clean glue line with a pencil around both sides of the bow.

Just like the rib tape, I started with a glue patch on the top edge of the bow, then let it dry as an anchor while working the bow tape. Again, using a shop towel to clean off the excess glue while wet.

I worked out the wrinkles while working the tape around the bow.  The bias tape worked well and with a little tugging along the way the wrinkles were not a problem.

 

Once finished, the tape looked decent enough.  Time to let it all dry fully, then do the final shrink of the fabric.

Practice Build Time = 2 hours