Nov 12, 2020     Fuselage access covers - (2 hours) Category: Fabric Cover

I finished fabricating, trimming, deburring, prepping, and priming the six access covers for the aft fuselage (one for each side of the forward stab tube, then an upper and lower on each side for the rear tube). I plan to cover these in the yellow Oratex just so they blend in as well as possible.

Following that, I began installing the rear heat box outlet under the floor, but realized that I fabricated it before installing the stringers, and now it interferes with the stringers. My backup plan is to just have the SCEET tube bend 90 deg to a flange screwed to the floor. This method will be lighter and a cleaner installation, but I will have some work to do filling in the existing hole in the floor.

  Nov 11, 2020     Fuselage access covers - (1.5 hours) Category: Fabric Cover

I started fabricating the covers for the aft fuselage access holes.

  Nov 10, 2020     Rudder cable exits - (1.5 hours) Category: Fabric Cover

I finished up gluing the rudder cable exit backing plates on each side, and also needed to adjust the rudder cable by shortening the 4130 tabs that set the distance between the rudder pedal horn and the cable shackle to achieve a full 30 degrees of travel. On the left side, I need to glue a .032 washer on the stop bolt to get the distance right. I also removed the firewall and deburred many of the holes prior to permanent installation.

  Nov 09, 2020     Rudder cable exit backplate fab and misc tasks - (7 hours) Category: Fabric Cover

Between the 6th and 9th, I made some back plates for where the cable exits the fuselage, and mounted the rudder so I could get the exit points just right. I also determined that the rudder travel was not reaching a full 30 deg so that will require adjustment. I also experimented with various means of filling in gaps between the fabric and fuselage members in the interior, but ended up removing the patches because it looked worse with them on. I went around the fuselage with a soldering iron to make holes for screws, bolts, cable exits, drain holes, pulleys, etc.

  Nov 05, 2020     Under Door Fabric and float patches - (1 hour) Category: Fabric Cover

I finished the right side under door fabric and cut out a patch to put over the float fitting area. Even so, It's hard to make that area look perfect. I might solicit advice from Lars.

  Nov 04, 2020     Under door fabric - (2.2 hours) Category: Fabric Cover

I glued the left side under door fabric with no issues. I was hoping to wrap it up around the door sill as a contiguous piece, but unfortunately I had to slice it at the bend in the door sill. Doesn't look terrible, especially if I install a door sill plate at a later date. I did the same on the right side, but didn't quite finish gluing all around.

  Nov 03, 2020     Under main door fabric areas - (2 hours) Category: Fabric Cover

Happy birthday Ella, and happy election day! I examined the remaining pieces of fabric and determined there is barely enough to do under the main doors, along with the back and bottom of the rear seat and the bottom of the main seats. So I started work on the fuselage side panels by trimming and tracing them followed by two coats of glue in the basement. The garage was too cold to apply glue this morning, but I will start on that tomorrow and hopefully get the fuselage gluing completed this week.

  Nov 02, 2020     Final shrinking part 2 - (2 hours) Category: Fabric Cover

I finished the final shrinking. Unfortunately, I experienced a runaway temperature condition on the heat gun while trying to even out the fabric attachment over the bottom longeron, and I burned a hole in the Oratex. So cleaned the area very well and glued a patch over the hole. It's great how easy repairs are, but I was hoping to to have repairs on my brand new airplane! This is the third time I've burned a hole in the fabric due to runaway heat (where I'm humming along at 450 deg, then suddenly a hole opens up on the fabric and I realize the heat gun is climbing through 800 deg F). There is one other on the fuselage in a very discreet location and another on the bottom of a control surface. The most significant repair to date is on an aileron where molten lead came out a unnoticed hole and burned away some fabric.

  Oct 27, 2020     Final shrinking - (2 hours) Category: Fabric Cover

I got part way through the final exterior fabric shrinking, including applying the heat gun to any edges where the fabric was glued a little too far around a curve. Then, we went on vacation.

  Oct 26, 2020     Fuselage top - (1.5 hours) Category: Fabric Cover

I spot glued, trimmed, and finished the top fuselage fabric and also organized my leftover Oratex pieces to figure out what to keep and what not to keep.

  Oct 26, 2020     Fuselage Tapes - (3.5 hours) Category: Fabric Cover

I glued down the 2" tapes along the vertical stabilizer ribs, and laid a 3" tape on top of the vertical stab. Then I ran two 3" tapes down the top stringers to the base of the vertical stab, and another 3" tape up the vertical stab. Because there were two tapes converging on one at the base of the stab, I decided to use a separate tape for the stab rather than trying the technique suggested in the manual where a single tape was used with a complex process of cleaning the glue off, gluing both surfaces, and shrinking the middle.

  Oct 25, 2020     Reinforcing tape and rib/stringer lacing - (3 hours) Category: Fabric Cover

I applied reinforcing tape over the vertical stab ribs, and also along the first few feet of top fuselage stringers behind the skylight. I then rib laced all of those areas. and applied a couple coats of glue

  Oct 23, 2020     Top Fabric - (1.5 hours) Category: Fabric Cover

After looking at it in better light, the top stringer to stabilizer transition is actually symmetrical. The garage lighting originally cast a shadow on one side that made it look lopsided. So I pulled out the piece of fabric I cut for the top, and marked it for gluing, then taped the top fuselage for gluing, and applied the first coat of glue to both.

  Oct 22, 2020     Left Side Fabric - (2 hours) Category: Fabric Cover

I spent all morning just trying to get the transition from the top stringer to vertical stab to lay flat and shrink the surrounding fabric. Two challenges remain with no clear way forward yet. The first challenge is the contour of the fabric is different on the left side vs right, likely because of a difference in how I pulled on the fabric before gluing. I had no idea it would be so different. Challenge two, somewhat related to the first one, is that there was too much loose material next to the transition area, so shrinking at high temperatures did not fully pull the fabric tight. I mitigated heating the glue holding the fabric to the top longeron and pulling it down over the longeron and re-gluing it, then shrinking the loose fabric that is now below the longeron. It not looks tight, but isn't as tight as I would like, and is still not symmetrical on either side of the vertical stab.

  Oct 21, 2020     Left side fabric - (3 hours) Category: Fabric Cover

I glued and shrunk the fabric at the forward end of the left side, and trimmed/glued the fabric down the stringer toward the vertical stab. Later in the day, I glued the fabric on the rudder post and vertical stab except for about 2 feet in the area around the stringer-to-stabilizer transition area which will require some special application of heat.

  Oct 20, 2020     Let side fabric Category: Fabric Cover

Using the same apparatus as I used on the right side, I stretched the fabric at the forward end of the lift side and marked it for glue application. I also marked and applied glue to the fabric and structure in the vertical stab area.

  Oct 19, 2020     Left side fabric - (2 hours) Category: Fabric Cover

I glued the fabric along the top longeron, the window and door frames, and the rear inspection frame. Then gave it an initial shrinking with the iron and heat gun. I feel better about this side regarding the upper stringer to vertical stab transition as I allowed for more material to make the fold over the top longeron. I recommend ensuring you have enough fabric at that transition before gluing any of the rudder post or anything else above the lower longeron.

  Oct 18, 2020     Left Side fabric - (1.5 hours)       Category: Fabric Cover

I used the magnets to set the left side fabric in place and started ironing along the bottom longeron. After the initial tack, I creased the excess along the tape line and cut it before gluing it all down. I followed with the heat gun and felt blade along the bottom. The second picture below shows the fabric in the area of the float mount. I plan to make another patch to go over this area to ensure it's weather tight before calling the fabric complete.

  Oct 17, 2020     Left side fabric - (1 hour)       Category: Fabric Cover

Last night and this morning I used magnets to preliminarily attach the left side fabric, then traced and trimmed it before removal. I then spread it out on the living room floor to clean and brush on the glue.

  Oct 16, 2020     Left Side Fabric - (1.5 hours)       Category: Fabric Cover

This morning I filed down some high spots on the fuselage and spot-painted them, and also riveted the round window frame on. I finished up the right side fabric by ironing down some loose edges, and finally riveted the lower forward aluminum backings using a combination of CCC-42 pop rivets and -4 solid rivets. I'm really glad that I re-made those.

  Oct 15, 2020     Misc fabric tasks - (1.5 hours)       Category: Fabric Cover

I painted the aluminum that backs the fabric around the gear legs, and also brushed glue in all the grooves along the sides both in the baggage compartment and between the right lower longeron and right side fabric. I also used JB Weld to attach the left side access frame at the tail and ironed on the right side round forward access frame for the tail's forward spar. I located it to be somewhat centered between the upper stringer and upper longeron so that the spar carry-through will be somewhat centered in the hole. This allows an opening big enough to get my hand in when the carry-through is not in place so that I can connect the trim cables when needed.

  Oct 13, 2020     Right Side Fabric - (2 hours)       Category: Fabric Cover

I visually completed the right side fabric piece by gluing all around the vertical stabilizer and shrinking with the heat gun and iron. I went over all the fabric with the iron at 130 C and will later do it again at 160 C. I still need to finish gluing around the top stringer and forward stringer, but will need to re-apply some glue in that area as I believe I already activated the existing glue with the shrinking.

  Oct 12, 2020     Right side fabric - stringer to tail transition - (1 hour)       Category: Fabric Cover

Using lots of stretching and tugging, and aided by strategic cuts in the fabric, I was able to attach the fabric to the stringer-stabilizer transition area. I was worried there would be difficulty here as it required a lot of stretching to avoid having large wrinkles in the area at the base of the stabilizer. Later in the day, I traced the stabilizer onto the remaining fabric and applied glue to the remainder of the stabilizer and fabric.

  Oct 09, 2020     Right side fabric - (0.5 hour) Category: Fabric Cover

I stretched and glued the fabric at the forward end of the right side to the stringers and top former, then did some shrinking to verify eventual satisfactory tightness. I think after shrinking at 160 C it will be amazing.

  Oct 08, 2020     Right Side Fabric - (2.5 hours)       Category: Fabric Cover

Hopefully the left side goes faster! I glued the fabric to the stringer above the first bay aft of the baggage door, then started working on the forward part. As it sat, there was a large longitudinal wrinkle in the fabric because of the shape of the forward fuselage. After pulling and heating a lot, my plan evolved to using large clamps to hold the fabric tight in multiple directions (forward and in), then use the heat gun on the fabric until the wrinkles were out. I had to stretch a little, heat a little, stretch a little, heat a little, etc., but eventually I got the fabric to lay nicely on the forward fuselage area, so I marked and brushed glue onto the fabric and fuselage stringer and forward former.

Then I moved to the back, which has proven to be more challenging. It's very difficult to stretch the fabric to contact the concave arch where the stringers meet the fuselage. The challenge is slightly abated by tilting the fabric over the stabilizer forward a little, but this causes a large crease all across the stabilizer and an even larger one between the stabilizer and top longeron. But I think I can avoid doing this by simply applying loads of heat wherever the fabric is taught while stretching it to contact the arch. So I brushed glue on the fabric, stringer, and arch to prep for this challenge.

  Oct 07, 2020     Right side fabric - (2.5 hours)       Category: Fabric Cover

I finished and somewhat shrunk the fabric on the right side up to the top longeron. I have been tacking it in place with the iron and going back with the heat gun and felt blade to heat it up again. On the door formers, the heat really dissipates so it's hard to judge how much heat to pump in there. Everything below the top longeron came out great. On top, it's going to get tricky and I'll need to use heat to stretch the fabric in some places. I'm going to start buy attaching the fabric to the stringer in the area over my baggage compartment (one bay aft of normal baggage compartment) and stretching from there.

  Oct 06, 2020     Right side fabric - (2 hours) Category: Fabric Cover

Yesterday I brushed the glue onto the fuselage and right side fabric piece. Notably, I only went as high as the top longeron on all surfaces as I wanted to ensure a tight fit there before proceeding to wrap it over to the top stringer. I also allowed small wrinkle at the top longeron near the vertical stabilizer forward spar so that there would be extra material to wrap over the curve from the fuselage to the stringers. I used the heat gun to shrink this wrinkle on the upper longeron so that there was no actual wrinkle in the fabric.

The shape of the forward fuselage is interesting to when it comes to wrapping, as the top longeron has a slight concave curve near the forward fabric termination. As it turns out, it was not simple, but definitely manageable.

  Oct 05, 2020     Fuselage rear access holes - (2.5 hours) Category: Fabric Cover

I fabricated, scuffed, painted, and attached nutplates to the frames for the rear fuselage access holes. I then used JB Weld to attach the rearmost frame on the right side in position. this is mainly to ensure it doesn't move when the fabric is shrunk, but the adhesion doesn't matter much beyond that.

  Oct 05, 2020     Right side fabric fit and tracing - (2 hours) Category: Fabric Cover

I positioned the large piece of fabric on the right side using the magnets. Comments on the forum suggest not following the distributor's advice on covering from the bottom longeron all the way to the top stringer, including the vertical stab. I can see that the fabric will certainly have some wrinkles when it goes on, but based on how much I've seen it stretch, I'm going to try it.

I plan to glue it to the bottom longeron first and then up the door post and rudder post. As it goes up the rudder post, I will give it a wee bit of slack to help when the time comes to stretch it over to the place where the stringers attach to the fuselage, but it will likely take some heat to help with the stretch.

  Oct 04, 2020     Prep for fuselage fabric - (2 hours)       Category: Fabric Cover

I finished up a few things inside the tail section prior to applying the right side fabric. This included torquing and pinning the bolt holding the aft pulley section and the bolt holding the trim crank (both are additions to the plans and not on most Bearhawks).

  Oct 02, 2020     Test fitting of left stabilizer and elevator - (2 hours)       Category: Fabric Cover

I bolted on the left stabilizer and elevator to validate my design for the access holes. I will have the standard small round hole for the forward stabilizer spar, but fabricated a unique rear hole frame designed to minimize the size of the access cover visible on top of the stabilizer while providing generous space underneath to facilitate access to the pulleys, trim cable hook-ups, and tailwheel spring bolt.

  Oct 01, 2020     Bottom Fabric - (6 hours)       Category: Fabric Cover

Though the bottom fabric took about 4 days, I consolidated it into a single post. It was fairly easy, and I left a little extra overlap at the leading edge so there would be extra glue surface securing it there. It was trickiest around the float fittings, but came out nicely.

  Jun 02, 2020     Aileron Oratex from start to finish - (3 hours)       Category: Fabric Cover

I intended for this post to be a sort of pictorial process description of how I'm covering the ailerons. But as it turns out, I just put my head down and did nearly all the covering without updating my build log. I will slowly update those as I go.

Other than seat frames, these are the first parts I'm covering. While they recommend that you begin with small pieces like trim tabs, I chose the ailerons for no good reason. The process will describe covering one aileron and the times recorded are for the second aileron after having ""practiced"" the task on the first.

20 min: cutting out fabric, clamping, and tracing structure onto fabric
55 min: cleaning fabric and ailerons, applying glue
85 min: initial fabric attachment and glue application to overlaps
25 min: shrinking with heat gun and iron


Notes:
- Heavy sharpie marks on structure or pencil marks on fabric will show through finished product. very light pencil marks are ok. Yellow marker is better.
- About 80 inches of rib stitching thread is required on each aileron rib
- Recommend curved needle, such as Osborne 5018 from ACS

  May 28, 2020     Filled gusset overlaps on flaps - (2 hours)       Category: Fabric Cover

I cut out the fabric piece to cover one aileron. The width of the fabric roll is more than advertised and was the perfect width for the ailerons with a comfortable amount of extra on the ends.

I spent some time on the phone with Lars recently, and his instruction was to glue the fabric to everything it touched. This way, there was really no padding required underneath except where there was an unusually sharp edge. But he also warned that EVERYTHING on the surface would be visible through the fabric. So I decided to at least apply some filler forward of the gussets on the ailerons.

  May 25, 2020     Prepping for Oratex work - (3 hours)       Category: Fabric Cover

This work included days of research while distilling the Oratex manual to a short document that I can reference. Also included a draft layout to determined be what part of my 30 yd roll or Oratex I should cut different parts from. Finally, a complete cleaning of the basement and organizing of workspace was in order.

  Mar 27, 2020     Seat fabric supports - (1 hour)       Category: Fabric Cover

I glued in the aluminum supports that hold fabric edges which are not attached to the tubular structure.

Of course, no later did I glue them in did I realize the ones on the bottom seat frame are on the wrong side. I attempted to remove them with a lot of heat but the effort was futile, so I made new ones. This mistake will mostly be covered up when the second layer of fabric is applied over the seat frames.

  Mar 26, 2020     Covering Seats - (10 hours)       Category: Fabric Cover

The last month has been quite busy with work and life, so I've snuck down to the basement a handful of times to play with the Oratex. After feeling comfortable with it, I started covering the front seats using samples that I collected at Oshkosh. The bottom seat will be covered in two layers, so I used up some random color samples that I had first and will follow with yellow. I'm glad I started on these as they will not be fully visible in the finished cabin.

  Feb 26, 2020     Oratex glue test - (2 hours)       Category: Fabric Cover

I conducted the Oratex glue test as specified in the manual to ensure my covering practices were up to snuff. To begin with, I glued a 1"" wide strip of Oratex to a piece of aluminum over a span of 6"" or so. Once it is dry, you take the loose end of the Oratex strip and hang a 1.3Kg mass on it and ensure the glue can hold it when the resulting force is perpendicular to the surface, as shown in one of the photos below. It held this mass just fine, and when I filled the bag with all the bolts (over 2 Kg) it still held just fine.

Next, you are supposed to increase the force until it begins to tear away the glue joint, then reduce the force back to 1.3 Kg and see if it still holds. Repeat this several times. It held perfectly well with my 2 Kg mass. I tried all orientations and the glue joint still held. I chalk this up to a resounding success.

While not a prescribed procedure, I wanted to test the strength in the tangential direction. I clamped the end of the fabric strip in my giant bench vise and lifted it off the ground! The glue joint was 1"" by 1.8"" at this point, That 1.8"" is about how far around a 3/4"" tube the glue joint would wrap, so is representative of real-world application. I don't know how heavy the vise is, but I couldn't lift it off the ground with one hand. I put a foot on the vise and pulled to failure, which occured in the Oratex and not the glue joint. Overall, this was a very encouraging test to show the strength of the process and the validity of my techniques.

  Feb 13, 2020     Oratex research and prep. - (.7 hour) Category: Fabric Cover

I organized the basement to create a workspace for fabric covering. I also read through the 62 page manual that Lars sent me. It still leaves me with questions, but I know enough to get started on some practice.