Fabric Covering

Introduction
There are several different covering systems out there.  I used Poly Fiber available from Aircraft Spruce and Wicks Aircraft Supply among others.  I could not have done this without having the process manual Poly Fiber sells that describes the details of how their process is to be applied.  Most of this I covered in my first blog (easyriser1.blogspot.com).  Here I have included some changes to that original process that I am now using whenever I cover a panel not to mention you will also notice changes to the internal structure that have since become my standard.  Details of these changes are covered in the relevant posts of this blog.
Use a small spot of Gorilla Glue on the LE where the half rib seats to lock it onto the spar.  Before the spanwise leading edge tape is applied all of the main and half rib cap strips should be coated with 2 layers of full strength Poly Fiber Poly-Tak cement.  This stuff will eat right through the foam I used so don't get sloppy.  I used a 1/2 inch brush to do this part.

Used 1.0 inch wide Poly Tape to run 5 spanwise runs from the root rib to the tip rib spaced 1.0 inch apart. I started the leading edge of the first run 1.75 inches from the spar leading edge as shown in the photo.  No magic about this measurement, just had to make a decision.

I still don't have a real good quantitative way of conveying how much tension you can put on these strips without starting to warp the spars.  Just pay attention by sighting down the spars as you apply them.  You should see no bowing of either spar.  Remember, you're going to be adding even more spanwise compression when you apply the fabric AND, this is unshrunk aircraft dacron tape so it's going to shrink a LOT more than your fabric store polyester cloth when you iron out the covering fabric.  Don't glue the strips to ANY of the ribs.  You want this tape to float until you have done the final shrink process to the covering to ensure an even fabric tension over the entire wing surface.

Wrap the tape around the root and tip ribs (already coated with glue) and cement in place.

Next, mask the spars at the fabric tangent line on both the top and bottom of the panel to avoid getting glue past this point.  If this is not done, you will likely get puckers anywhere along the spar where the fabric is even just a little slack as it glues itself to the spar past the tangent point.  Once this happens, it is nearly impossible to get them out so I see this as an easy preventative measure that's easy to do.

The following notes and process pertain to the use of Poly Fiber covering materials and processes.  I followed their manual for the most part.  Attempting to complete the covering process without the manual is not the smartest approach.  I highly recommend just buying a copy of the manual when you order the chemicals.  Apply full strength Poly Fiber Poly-Tak cement to the entire perimeter of the airframe.

TO BE CONTINUED

1/14/18