Covering The Tail
Both AFS & Poly Fiber Methods



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We will be describing the process of covering the tail section - elevators, rudder and the elevator & rudder stabilizers.

The Poly Fiber method instructions of gluing will follow the AFS method at the bottom of this web page.

For more information on Poly Fiber products and technique, check information available at Poly Fiber Aircraft Coatings.

NOTE: Aircraft Finishing Systems (AFS) is no longer in business. However, the production rights to the former AFS of Montana has been assumed by Stewart Systems of Washington.


Tapping Down Edges

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Prior to taping the gusset edges, it is recommended to first use a plastic mallet to tap down the edges as close to the aluminum tubing as possible. This should be done on "ALL" gussets and sheet aluminum edges throughout the plane. This will help in the long term effect of reducing the gusset edges from cutting or wearing through the covering or skin of the plane after the plane is flying.

Taping The Edges

The best tape to use for taping off the gusset edge and rivets is a Dacron First Aid tape available at WalMart. The covering is also made of Dacron, so if it ever gets wet, it will not mildew or decompose. For all the edge and rivet taping throughout the plane, you will need to buy about 15 to 20 rolls.

         
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Before applying any tape or glue, be sure to completely clean all aluminum surfaces to be taped or glued with MEK.

See MEK Warning Information before using.



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Be sure to apply three (3) layers of the Dacron tape over all rivets and sharp edges, like the gussets and tube ends.

         
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If you would like a more finished look after covering, try using Super Fil two part epoxy to fill the ends of the tubes. (Available at Aircraft Spruce and other aircraft part suppliers.) Using a standard file, sculpt and smooth the tube ends to conform with the tube contour. When using this method, taping the tube ends is not used.

This method is also described in the "modifications" Section of the "Articles" web page.
         
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Masking For Straight Glue Edge

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When getting ready to apply your glue to your tail feathers, it is best to use an inexpensive masking tape to create a "straight" glue edge. Mask for about a 1/2" glue strip along the outside aluminum tubing and about a 1/8" strip along the center cross tubing.

         
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What Glue To Use

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There are two primary types of gluing systems, Poly Fiber's and AFS.

Our builder will be using the AFS bonding system, using CecoBond Cement and an AFS Heavy Duty Cleaner.

         
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Using a small paint brush to apply your glue, apply two coats of your glue to the masked areas of the tail feathers, allowing each coat to dry between applications. When done and the glue is completely dry, remove the masking tape slowly by folding the tape back onto itself and pull in a slight outward direction from the glue. This will help to keep the glue from lifting off the aluminum tubing and give you a clean glue line. This is done prior to placing the fabric sock onto the tail feather frame.


Adjusting The Tail Sock To The Frame

This is perhaps the most difficult part of the covering process if you want a clean, professional look when finished. What we will be describing is how to keep the sewn seam aligned with the outside center of the tubing while gluing and shrinking the fabric.

NOTE: it is "IMPORTANT" to determine which tail feather you are working on, right or left as well as determining top from bottom. The reason for this is, you will need to first apply the glue in the correct direction for gluing the "BOTTOM" sock flap "FIRST", not the top flap.


AFS Method
Covering Your Tail Feathers

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After your glue on the outside edge and center cross brace tubes have dried thoroughly, slip the appropriate material sock onto the tail section.

Using the masking tape, tape off a glue line on the bottom of the hinge side of the aluminum tube. The glue should be applied from the glue line around the tube to the inside of the tube. Apply two coats and allow to completely dry.

         
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While working with the sock in preparation for gluing it to the aluminum frame, you may want to use hand spring clamps to keep the sewn seam centered on the outside edge.

This would also be a good time to adjust the inner sewn seam flaps to all face toward the bottom of the tail feather from the sewn seam itself. If you allow the seam's flaps to alternate, both up and down, your tail section will not look as good or professional as they could be.


Securing Bottom Flap

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You will now have to cut the sock at the two corners to create flaps at the top and bottom of the sock. "WARNING", do not cut the sock right up to the aluminum tubing. You want to stop cutting about 1/4" from the tubing. Lightly pull the bottom flap up and around the tube and rub it down into the glue with your hand. At this point, it can be pulled off and repositioned as needed.

         
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Once it is fitted around the tube, you can do any additional cutting and repositioning to obtain a good fit. Now take a hot iron and 'set' the glue joint with just a small line down the front of the tube. You can take a pencil and mark a cut line on the excess fabric on the inside of the tube. The excess fabric can now be gently pulled up and cut with the scissors. When fitted and the excess cut away, you should have a fabric wrap of about 270 deg around the tube.


Using your hand, rub the fabric down onto the glued tube working out any wrinkles and securing a good bond. At this point, the fabric can still be pulled away from the structure and repositioned if needed.

Using a hot iron set at about 225-275 deg F., iron the fabric down into the glue bed by using heat and pressure. The heat from the iron softens the bed layer of glue allowing the pressure to push the fabric weave down into the glue. You should see a slight darkening of the fabric where you have heat bonded the fabric to the glue.

Working in strips of about 6" to 10", reapply glue over the glue bond area and rub it down into the fabric with a Blue Scott Towel (white paper towels leave too much lint behind). Be sure to wipe away any excess glue left on the surface of the fabric. Allow to dry.

Securing Top Flap



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Again, mask off the top and bottom glue line for securing the top flap. Apply a bed of glue and remove the masking tapes. After the glue has dried, pull the top flap down over the tube and rub the fabric down into the dried glue. Using the hot iron, secure the fabric down with a line down the front of the tube. Using a pencil, mark the line to cut off the excess fabric and cut it off. Lay the fabric back down into the glue bed and rub it down good with your hand. Once it is located where you want it, again use a hot iron and pressure to force it down into the glue bed.

         
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After it is ironed down, working in short strips, apply glue on top as before and rub it down into the fabric using the Scott Towels. Be sure to remove all glue from the surface of the fabric with the Towels.


Shrinking The Fabric

Cooking Thermometer
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Start with a household iron set at about 225F to 250F or 107C to 121C. Most builders will use either a $10.00 cooking thermometer or the far more accurate $70.00 Raytek Minitemp MT4 laser, infrared thermometer, available at www.infrared-usa.com.

When shrinking the material at 225F, you will need to alternate from one side to the other as you only want to take out some of the slack at first as you "DO NOT" want to shrink the fabric so much as to pull the sewn edge off the center position of the outside tube.

         
Raytek Minitemp MT4
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You will have some creases along the seam's edge and will need to iron these out at 350F. Once you have completed the lower temp. shrink, you can reset your iron to about 325F to 350F for the final shrink. Again, keep alternating from side to side as you shrink to keep the sewn seam in the center of the outside tube. Once this is finished, use MEK to activate the glue on the aluminum tube and secure the fabric to the tube along the sewn seam and center cross tube.

         
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Poly Fiber, Poly Tak Method Of Gluing

Before applying the glue edge tape, be sure to completely clean all aluminum parts to be glued with MEK.

See MEK Warning Information before using.

As the method of covering your tail feathers are the same for both methods, no additional photographs are needed. The only difference in the Poly Fiber method is setting the fabric into the Poly Tak glue.

Use a small 1-1/2" paint brush to apply your Poly Tak glue. Wait until the first coat of glue has fully set up before applying the second coat. Once both glue coats have completely dried, remove the masking tape by folding the tape back onto itself and slowly pull the tape off.

You will need to apply two coats PolyTak glue from the glue line and extend around the aluminum tubing to about the middle of the inside of the tube for the bottom glue flap. After applying the Poly Tak to the glue flap area, outside perimeter of the frame and a 1/4" strip down the middle, both sides, of the center cross brace, you will be ready to seat the fabric to the glue using MEK.

With the elevator sock slipped over the frame and corners cut to make "flaps" to both top and bottom, you are ready to seat the fabric into the glue on the frame. Fold the bottom flap over the hinge tube of the frame and adjust for a "ALMOST" snug fit. Use a clean 1-1/2" or smaller paint brush to amply apply MEK to a 6" strip of the fabric which is setting over the Poly Tak glue. Use your index finger to rub the MEK saturated section of fabric and work the Poly Tak up into the fabric until the MEK has evaporated.

CAUTION: You want to do this "JUST ONCE", so you need to get the glue up into the fabric the first time. If you do not, reapplying MEK will only serve to separate the fabric from the aluminum tubing. If this happens, you will need to remove the fabric, clean off all glue residue from the aluminum tubing and reapply two coats of Poly Tak and start over.

Once you have finished seating the fabric to the aluminum tubing and removed any access fabric, you are ready to mask off the glue area for the top flap. When applying the glue edge masking tape, be sure not to set the tape beyond the area on the covered tubing where the fabric leaves the tube or your fabric will be pulled down at this point. This will be noticeable when shrinking the fabric later. You can now apply the two coats of Poly Tak and when dry, remove the masking tape.

Now, fold the top flap over the tubing and as before, apply MEK to about 6" of the fabric and rub the glue up into the fabric. Continue this all the way down the tubing until the entire top flap has been glued down.

After both glue flaps have been seated into the glue, you are ready to do the initial 250F degree shrink of the fabric. Remember to alternate between ironing each side to keep the sewn edge from being pulled off center of the parameter tubing. Once the fabric is "slightly" taught, it is a good time to use a single sided razor blade to remove the excess fabric from the top glued flap. This is done by folding the fabric back onto itself, place the razor blade into the fold and "FLAT" with the aluminum tubing, then slide the razor blade down the tubing cutting off the fabric excess and making a straight, smooth cut line.

Now you will want to reset your iron to about 350F degrees and iron out any fabric creases along the parameter of the elevator as well as the glue flap area. After you have finished this ironing of the outside edge, use MEK to seat the fabric to the tubing along the outer perimeter edge and center cross brace like you did for the glue flaps. Make sure your seam is as straight as possible as you seat the fabric into the glue.

You are now ready to do the final 350F degree ironing of your elevator.

Repeat the above Poly Fiber process for the remaining elevator, rudder and stabilizers and you are done.


That's it, you finished one section of your tail section. Repeate the above processes for the remaining elevator, rudder and stabilizers.