Carl, it looks really nice! I painted the primer on my wings today so I am about ready to cover. I am sure I will be calling you with lots of questions:D
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Carl, it looks really nice! I painted the primer on my wings today so I am about ready to cover. I am sure I will be calling you with lots of questions:D
This pre-glue step will be repeated for the 1" tapes covering the false ribs. I didn't order sufficient 1" tape. After the fuselage is covered I'll know what additional materials might be required. Any left over wider tape can be cleanly cut down to 1" using a long straightedge and a rotary cutter. Or left over fabric can be used to make the tapes. Both of these options will leave a thin white line where the color coat would be missing. A red sharpie pen is a close enough match but I'm more in the puddle jumper rather than the show category and probably wouldn't bother. All in all, ordering a 1" roll of tape is easier and, with luck, can be supplied from Lars' Alaska office rather than shipped from Germany.
My rotisserie doesn't seem ridiculously tall and, when inverted, the top of the rudder just has a few inches of clearance from the garage floor. Still, it took a simple scaffold of cinder blocks and 2 x 8's to be tall enough to fabric the bottom. Covering the bottom took three days.
- Lay a wide piece of fabric on the bottom, clamp one side, trace a cutting line down the other side.
- Transfer the fabric to a 4' x 8' table top for cutting.
- Get nervous and measure the fuselage width down a series of reference points. Then transfer these points to the fabric and draw connecting lines as a sanity check on the rough cutting line.
- Cut the fabric and relax when the test fit looks good.
- Scotchbrite the airframe, wipe clean, then paint double coats of glue on both tubes and fabric.
- Wait overnight then use heat and pressure to secure the fabric around the perimeter of the bottom. Cut slits where necessary.
- Come back the third day and heat shrink
Oh the memories.
Looks good Carl
Your plane is looking nice Carl, adrenalin runs high when your about to make those cuts into large pieces of fabric. Thanks for sharing your progress.
Carl, that red is stunning. Do you know the Oratex colour name ?
David,
The fabric is Oratex Fokker Red. They have a limited set of colors and I believe this is still the only red. The USA distributor, Lars in Alaska, quickly mailed free samples of various colors. No idea who might handle the fabric in Aus.
I decided on red after seeing a picture of Gary's (Colospace) smiling face, holding a freshly covered rudder or elevator in his thread.
Yes it certainly brings back memories (seems so long ago). Looking real nice Carl.
One of the beauties of Oratex is that, once you've shrunk it tight, you not only have the satisfaction that the taut fabric brings to any build, but also the feeling of completeness that having the final finish brings.
Finish tapes still to go obviously, but I found that to be a no brainer except around some of the smaller tail surface radii.
Thanks Carl. I guess the Fokker red is based on the WW1 colours of the Red Baron ... another good reason to use it, although I'm using Poly Fibre per the factory kit so I'd have to try and match.
I'll be happy to mail you a swatch from the many scraps that are piling up. That might help get a reasonable match in the paint system you are planning to use.
PM your address if you are interested.
I really am enjoying reading the covering process. It's making it a little less daunting for me. I'm also going to use Oratex, but have not decided on color(s) yet. I'm going to have to get a few samples to look at.
I can also provide silver and yellow if you let Carl know in your PM that he can provide me your address.
Eddie
Eddie, Sent you a PM. Thanks for the offer.
I am curious, do you tape wider with blue tape than the finishing tape or narrower so you don’t have glue not being covered by tape and being exposed? If you put the blue tape narrower than finish tape so the finishing tape completely covers the glue? If you do that isn’t the edge of the finishing tape going to peel up where there was no glue?
The Oratex finish tape comes pre-glued. I just want better adhesion over the reinforcing tape that is under the rib lacing. Also the flat, waxed lacing thread that lays down so beautifully, isn't strictly approved by Oratex. Before stitching I scraped both sides of the thread a couple of times with a thumb nail then ran it two or three times between tightly gripped folds of an alcohol soaked rag. There was no obvious was build up while stitching.
The blue tape goes just outside the rib lacing holes (burned with a soldering iron). The 2" wide tapes easily cover the maybe 1 1/4" glue strip. Tapes are easily applied with a little extra time spent pressing the tape against either side of the lacing. The pre-glued edges look nice and secure. Contrary to another thread, the edges of the Oratex tapes are coated with color - not raw. At least the red ones are.
I used "straight" finishing tapes but "pinked" are available. No idea how easy dealing with those little pinked triangles might be.
I think I referred to them as "raw" in another thread. I just meant that they had no additional topcoat to blend them into the fabric underneath, not that they didn't have color at the edges. I also wasn't trying disparage Oratex. After doing a wing in Poly Fiber, I'm honestly not sure which way I'd go if I had it to do over again. If Oratex had a little bit more in-service history, it would probably tip me that direction, so I hope I didn't come across as overly critical. I'm probably just trying to convince myself that I made the right decision.
Ah these pesky forum posts. They can be as bad as emails. My "raw edges" comment did sound kind of snotty and I apologize. I had read your post as non-colored and off I went!
And you are absolutely correct. A big downside of the Oratex systems is lack of paint coats to "soften" the edges along the finishing tapes and joints. Here is a situation where that can be a problem. When applying the top fabric to the wing, I used the straight factory edge of the fabric to make a straight, clean line overlapping onto the underside of the trailing edge. Neat as a pin. However, it is very tough to get a clean, straight line where the fabric overlaps the bottom fabric on the leading edge. You can cut the Oratex fabric exactly to size, but you risk shrinkage and a wavy line while you use heat to bond the glue. So the factory recommends you leave a few inches of "gripping" fabric and do the following:
- Use masking tape to make a clean glue line on the already attached bottom fabric. Remove the tape before the glue dries!
- Apply glue to the top fabric so it will more than overlap the masked glue line on the bottom fabric.
- Attach the fabric, using heat and pressure to bond the glues.
- The glued surface of the top fabric will not have a good bond to the masked area on the already applied bottom fabric so you can fold the fabric back, make a sharp crease, and cut neatly along the line.
- Finish by heating and pressing the clean edge of the fabric.
Sounds easy enough and the factory guy doing the YouTube video is an artist. In practice, I had a very hard time getting a straight cut along the creased fabric. The line on my first wing is jagged enough that I masked and applied a couple of coats of glue so it would melt and "caulk" the imperfections in the line. With experience, the second wing went much better. Of course, with so many stages of the project, you are often approaching major jobs as a fresh faced kid.
I'm happy with the Oratex, particularly in light of my complete lack of painting skills and equipment. With care you can do a very nice covering job. But there are downsides to the process.
For what it's worth, there are certainly steps in Poly Fiber that the manual and the pros make look/sound easy, but the finesse required takes more than a practice kit or two to develop. I guess there's a reason we do this solely for recreation and education. Sometimes more the former than the latter ;)
The triangle edges on my pinked tapes were pretty harmless. Not to say I haven't found some that needed addtl attention..
With regard to the edges not having color. My yellow fabric, once cut, does have a white edge. So, when I cut the holes out for the rudder hinges I had to apply yellow paint on the edges to dress it up a bit. I think that the tapes, being made from the thinner fabric, don't show that same white edge. I bought some sample fabric from the thinner line and when I cut it it doesn't show white.
Eddie
Might send a letter to the editor of the local paper, letting them know I've found another use besides lining the cockatoo's cage. This pattern matches the sides of the fuselage. Should you go this route, be sure to flip the paper when cutting alternate sides.
With the tail feathers and wings complete, I expected covering the fuselage would be a snap. But things didn't work according to plan. The idea was to use the straight factory edge of the fabric to overlap the existing fabric on the fuselage bottom. The technique of masking tape, two coats of glue, then quickly removing the tape, left a neat line of glue. Then I started test fitting the large piece of fabric along the line - using 1" green masking tape to hold things in place. The plan quickly fell apart with the fabric naturally bunched in places and too tight in others because of the nice curves of the fuselage. Being slow to catch on, I doggedly stuck to the plan and spent an entire evening not making any progress.
When things aren't working, walking away from the project usually helps. The next day I used the trick described in applying the top wing fabric. The part of the fuselage fabric that overlapped the bottom fabric had a larger than necessary area of glue. The side fabric was laid with a generous overlap of the bottom and rested neatly along the fuselage. A small iron tacked the fabric in place, followed by a hot air gun and pressure felt along the entire length. Overnight wait for the glue to bond, followed by air gun and hot iron to tighten.
Finally, the excess bottom overlap fabric was peeled back and creased along the clean, straight glue line on the fuselage bottom. Since glue was only on one piece of fabric, there wasn't the strong, glue-to-glue bond. It would take a lot of strength to separate the properly bonded fabric pieces and you will be able to create a straight crease. A sharp, short pair of scissors was run along the crease followed by the iron the secure the edge of the fabric. Finishing tape will complete the job.
You’ve described pretty accurately how I did it too, Carl. Sorry it was a pain, but your work looks top notch! Keep it up.
Great work Carl !. Keep it up. I'm travelling a bit behind you and enjoy your thread.
Its looking good! I will be using Oratex also. I think I follow what you are saying, but is there any videos online showing this?
I'm not going to lie: I think I'm feeling a little Oratex envy.
Here is a video of the technique. The "artist" used a second layer of masking tape to have a thin, unbonded glue line. When the extra fabric is folded back, creased, and cut there will be a roughly 1/8" edge of fabric that needs to be ironed down. His extra glue line will secure that edge. I use normal, blue painters tape and don't dare expose it to the heat necessary to bond. So the tape is removed before ironing. This still leaves the 1/8" edge. It gets ironed down, held by the single surface glue. This will be covered by finishing tape. It's not really a matter of strength - just securing a clean edge.
https://www.youtube.com/watch?v=_y-zePW3uhE
I wish Oratex had had some of those videos available when I did mine... had to figure out much of it myself.
Looks Great Carl. Im sure you enjoyed the part of gluing the fabric to the aluminum door angle as much as I did. ;)
Yeah, like John said! It was a bit like being a early settler pioneering the wild western frontier.
Carl,
It does look really nice! I have also decided on Oratex and I am always interested in seeing how you guys are doing everything. I tried with the practice kit and I definitely need more help so more practice kits are OTW. It didn't take me long to figure out that the guys in the videos definitely have a talent that I don't. I also wish there were more videos on the application process showing and explaining different scenarios. Everyone one here has definitely been a great help.
Brett
As you can imagine, I'm not crazy about posting this picture. But sharing the mistakes is all part of the forum.
I've described how two glue coated Oratex surfaces have a very strong bond when heat / pressure activated, but you can take advantage of the weaker bond when only one of the surfaces is coated. The technique is to have a sharp glue line on one fabric and a more generous, overlapping glue surface on the second piece. Apply heat and pressure to bond, let cool, then peel back the overlapping fabric to the sharp glue line and trim off the excess. The first time I tried this, overlapping the wing covers, the final creased line was pretty jagged. The second and third time, 2nd wing and 1st fuselage side, gave beautiful lines. This 2nd fuselage side covering gave the mess you see in the photo.
I had a very generous overlap of fabric but it was more securely bonded than expected in some spots and was a bear to peel back. There really was too much overlap to leave in place and most areas didn't have the double glue bond so it had to be peeled back. The photo shows a couple of spots where the glue bond actually peeled the color layer from the fabric.
To be clear, trusting a weak single coat bond between two pieces of Oratex is definitely not a factory suggested technique. In the video linked in an earlier post, the overlapping layer was applied to a type of "masking tape" not to a piece of Oratex. The video doesn't say, but Oratex sells a tape that looks like the material in the video. If you are considering Oratex, it would be smart to call Lars (BetterAircraftFabric.com) the US Rep based in Alaska. Lars is a very down to earth guy and will give straight answers to any questions about techniques.
Oratex glue is activated at 100C and the fabric just begins to shrink at 110C. This conveniently lets you bond the perimeter of the fabric before starting the shrinking process. After some thought, the two situations where I had problems were times that I had completed shrinking, floated a 160C iron over the entire surface, then concentrated heat along the glue lines. In the photo, I was thinking this final step would insure the tubing had heated sufficiently along the entire length. I believe this extra heat "melted" the dried glue and let it bond to both fabric surfaces. When you are applying Oratex to a surface, it's not uncommon to apply a little extra heat release the fabric - to remove a wrinkle for instance. In the two "clean line" situations, I had only used the 110C temp before folding and trimming.
This isn't an earth shattering situation. It's on the bottom of the fuselage after all. Before applying the finishing tapes, I'll use some spare fabric to make a long "patch" strip to cover the area. This is how minor damage to an Oratex covering is repaired so it is certainly suitable for this cosmetic problem.
Finally, yes that is a black fuselage tube showing through the Oratex. To be fair, the top of the fuselage isn't covered, the garage door is open on a bright sunny day, and there is a 4-tube florescent light just above. I haven't rolled the plane out in the sunshine yet so I really don't know how much of the skeleton will show. I won't find it unattractive.
Well Carl, That stinks. Nice thing is, its on the bottom. I had my silver stuff out in the sun and I didn't notice transparency. Not sure if the silver fabric is less transparent or not. The most undesirable thing I have noted is that the yellow 6000 fabric is slightly lighter in color than the thinner 600 fabric that make up the pinked tapes that are applied over it. Eh, not so bad. There is nothing that says I can't use my left over Poly Tone to just paint over the rudder and elevator.
It was completely my mistake. But think how good I would be a Oratex after covering three or four planes.
Carl, I had to ponder a while over my Chipotle burrito tonight before I recalled how I trimmed my overlaps. Back in that long ago time, there were no videos really and little in the way of instruction. (And as I was doing the work from early in the morning, I soon learned that Lars was essentially living on German time, so I tried not to call him except if I truly got stuck.)
Anyway, I'll try to relate how I worked out to do the trimming that went well for me 99% of the time.
I would of course apply adhesive in the desired width to the underlying layer of fabric. I would apply adhesive excessively wide to the underside of the outer layer. When dry, I would insure I was happy with the positioning of the fabric and then tack bond around the periphery well away from where I expected the final trim line to be. When happy with that, I would run the iron down that same "line" around the periphery (again, this is 1, 2 or 3 inches away from the final cut depending on how much overlap is required). I would then typically fold the top layer fabric back so I could see were the edge of the adhesive was on the underlying layer and pinch a small fold into the outer layer fabric periodically along the edge. Using these pinched locations, I could lay a straight edge in place to draw a light pencil line on the inside of the outer layer fabric. I would then just run my scissors along the line to shear-cut the fabric. Then it was a simple matter to finish ironing down the complete overlap. I would apply a couple of lines of adhesive along the cut edge as recommended and, once dry, proceed to the finish tape.
Hope that was clear. Seemed simple and worked well for me.
Gary,
That's pretty much the same process I used, except using a thumbnail to press a crease in the fold as a cut line. It was just in this instance, the glue on the overlapping made a very "good" bond where there wasn't a glued surface on the second fabric. I think this was caused by a hotter iron than the 100C required to bond the glue but I'm just guessing.
I will continue to use the technique while finishing covering the fuselage - only using a 100C iron on the overlaps.
What did you do on the wingtips and top of the rudder? Isn’t there a foam peice that you had to shape? Wondering if the heat will melt the foam parts you had to mold? I am guessing you fiberglass’s them?
Not sure what Carl did but I used Hysol over the foam on all empennage tips and had no issues with melting Hysol or foam at iron temperatures up to 350F. As long as you don’t hold the iron for too long in the one spot you should be ok.
Much the same as David, except I used West Marine epoxy with a fairing additive to make it easy to shape and sand the tips. No particular reason to use this product other than I had it on hand and have used it for years in other applications. No problems with the heat but didn't rest the iron in one spot.
Also have the thin, fiberglass Laker Leading Edge. No problems with heat but was aware of the potential and kept the iron moving.
I have recently mentioned my problem in another post. I used foam and Hysol. I had significant difficulty wrapping the Oratex smooth on top of the rudder. I spoke with Lars and it was recommended to use 400 degrees to get the fabric to shrink and smooth. Well, I couldn't do it without melting foam. I could feel it softening the foam as well as the Hysol. Needless to say, I have what appears to be a first graders paper mache project on the top of the rudder. I will always recommend that you use wood or some other more heat resistant substance. Somehow, my horizontal stabilizer tips worked out fine. And others have succeeded as well. So, Im not saying it will definitely be a problem. The foam I used on the rudder was of substantial size. I didn't just fill in the gap between the rib and the perimeter metal. I built it up to provide a more flat top. That may explain why Carl and others got away with it without problems.
Eddie
I only used the kit supplied foam on the horiz. stab and coated with Hysol. After that aggravating experience, I went to using balsa for all the remaining tips. Having said that, I did not have any heat issues with doing the Oratex over the foam.