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Oratex Fabric

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Roger Peterson

Registered User
Sweeny, Texas
Dave Calkins has request that I start a thread on Oratex Fabric, so here goes.

First I will try to give you a few URL's to look at to get some basic information:

Lars Gleitsmann
4621 Caravelle Drive
ANC AK99502
lars@betteraircraftfabric.com
http://www.betteraircraftfabric.com

http://www.supercub.org/forum/showth...7-Light-fabric
http://www.oracover.de/
http://forum.bearhawkgroups.com/view...304f32aa6c1dc9
http://www.g-tlac.com/oratex.html

Do a search on the internet for Oratex Fabric and you will get many hits and a lot of good information.

Then read my thread titled: N3150P Experimental PA11, on all the information relating to Oratex.

First, Use Oratex 6000 to cover wings, airframe, tail feathers etc. You can use Oratex 600 to cover any metal or other things that do not need the strength of the heaver fabric.
Call Lars for samples. He is great to work with and responds very fast.

When you get your samples, cover something to get a feel for how the fabric is to work with. But as I learned the hard way, get the right equipment first and get it calibrated.

I ordered a small Iron from Lars, about $35.00 and they shipped it from Germany with the fabric. It is great. You will need a 120 vac adapter to use it but they are available on the internet.
Next you must have a digital readout heat gun. Expect to pay around $250.00 for the heat gun and there are many to choose from in that price range. Stay away from the cheaper ones.

Now before you start covering anything, forget everything you know about shrinking fabric. This is a new ballgame.

Cut some 1" strips of fabric and using both the iron and heat gun, find out how hot you can get the fabric without it shrinking. Do this on both fabric just stretched across a open span, like between ribs, and fabric being glued to a metal tube and also fabric stretched over a leading edge. The temp is going to be different for all three. They are time dependent also, you can hit it with high heat real quick or a lower temp for a long period of time. Start out low and work your way up until you find the max temp you can use in all three areas without getting any shrinkage.
When performing the above tests, coat both the fabric and tubes or alum you will be testing on with adhesive so you get a good idea of how it works. While getting your heats calibrated that you will use, you can just as well run some pull tests on the fabric and adhesive.

I am sure you all have been warned that you should never use a heat gun while covering a airplane, that is probably true until you use Oratex. You wouldn't want to try to cover a plane with Oratex without one.

Now when you have run all the above tests, start all over and do it again finding the temp that is too hot for just sticking it down and where it starts shrinking.

Keep going, because you are going to want to run comparison pull tests on these glued joints also.

Now start all over again, and find out where too hot is. You will know it when you see it.

You need all this data, before you start messing up large chunks of fabric. The Oratex people cannot give you this information, because they don't have the same equipment you do and even if they did, they might move a lot faster than you do, or slower, who knows. You are learning what combination of heat and time do what to the fabric. You are always better off to use a lower temp and move slower to accomplish your task.

Next when running your higher heat tests, to shrink, glue your fabric between tubes, like two longerons, to check how much shrinkage you can get. Get to know your fabric first before you start covering. When you do start, start on something small, not a wing or the fuselage.

The tapes you will be using are preglued. Order 600 tapes. You don't need them for strength so get the lightweight ones. They just show up less and stretch easier than heavy ones.

Go to the thread N3150P Experimental, and look at the pict of the first side of the fuselage and then the pict of the second side. I saved the first side, but it was marginal.

You can stretch the tapes and fabric if you have enough strong friends. Don't expect your 110 lb wife to be able to pull hard enough. Those of you who have one that goes over 250 might give it a shot though.

Always let adhesive dry for a day on the fabric and metal before sticking down with heat. Don't hurry this, it don't work.
Use the brush they recommend.
Order release paper and always use it when using the iron.
Go to the gym and get to know some real strong guys to help stretch tapes and fabric. Good body builders usually don't drink as much as your pilot friends, so won't take as much beer.

I am old, so have probably forgot more than I am putting down, but just because you have already covered 10 or 20 airplanes, don't skip the above. If you do, Call Lars and tell him you will be ordering more fabric soon.

More to come. Feed back and questions will help.

Rog
 
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HI Roger, How much does a complete cover job weigh? I looked on the website and can't seem to find anything. Also, what is the approxamite cost to cover a cub?
 
I did everything but the wings including the cowl and spent about 6,000. I am guessing probably 9,000 total. but no paint, and all the labor that goes with it. When the fabric is on, you are done.
Have no idea about the weight, forgot to weigh anything, but it must be about 25 or 30 % of a regular cover job. Maybe Lars can give us the weight per sq ft of the fabric.
 
According to their website it's 155g /sq meter which works out to about .52 oz per sq foot so a normal cub cover job would be about 27-33 lbs when you figure the weight of tapes and dried glue.

Jason
 
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Agreed, good thread going here. Always interested in new and improved materials and techniques.

Jason, thanks for researching that. Just for reference, what would comparable weights be for more traditional systems, e.g., Ceconite, Stitts/Polyfiber, and Stewarts?

Thanks. cubscout
 
Stewart Systems is .75 oz per square foot which gives you about a 38-45lb cover job.

Jason
 
Jason. I still want to do a StewartSystems cover job, and likely will on my next one. ..just fyi.

This Oratex sounds exactly like what the model airplane crowd know as "oracover", also marketed as "ultracote".

It is fascinating to think that now a Cub or Champ or whatever can be covered like a model airplane, with the topcoat already on the fabric.

I am interested in others' results. Thanks
 
Jason, how much is Cub covering package w/ Stewarts? I think substantially cheaper. There are always trade offs.
 
Is this an apples to apples comparison? Can the Stewart' be "built" light? I remember someone mentioning only painting through "silver" or some primer type paint job to save weight and would this compare to the limited finish on the Oratex?. Does the finish paint add strength to the fabric in some way? Frankly for my mission I would like to only have wings and control surfaces covered but it seems the fuselage fabric is part of a two part system of support even there.
Restating my question: If you used Oratex with it's limited finish "gloss" or used Stewart's with a light matted look finish would the weight difference be more than a couple of pounds and does Oratex have any superior structural qualities at that paint/finish level? The description of application warnings in the first post coupled with the higher cost would only be worth it to me if Oratex was 20+# lighter apples to apples. When taking Jason's class I was impressed as to how forgiving the Stewart's was until the finish coat and since I plan a "spoof can" job :) for that so it won't be a concern.
 
I don't want to get in to thread creep here but anyone looking for info can email me directly. I am more than happy to share information.

Jason
 
Jason, we're all friends here. If someone doesn't like a little thread creep, they can go over to some other website and badmouth you there.

forgettaboudit!!
 
LMAO Dave, very true but Im just trying to be respectful of your request for an Oratex specific thread 8)

Jason

PS - We can start a second thread just about the different covering systems or just a Stewart Systems specific one. I'm more than happy to share info
 
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Thats ok Jason we're more then happy to bad mouth you on ether thread.

DW
 
Jason, the wings on my plane are Stewart System and they will be painted with Oratex paint. The first time Oratex paing has been used in the US.
Also, I think Lars has a post ready for this thread, so will be able to get his 2 cents in also.
Until I tried Oratex, Stewart System was the greatest thing I had seen. Also Oratex is simular in that there are no fumes. I have nothing but good to say about both of them.

There are things that you can do with Stewarts that you can't do with Oratex and the same goes for Oratex.

If I were to start another plane tomorrow, I would probably use Oratex because of its toughness and ease of application.
I would also like to do a plane in Stewarts, no Ekofill or paint and a vinyl 3M Wrap. Think I could make a great looking plane. Also put some neat designs on it.

Back to Using Oratex. When stretching the Oratex around curves like the rudder or elevators, I found it worked great to apply heat with the heat gun while doing the stretch. Not enough to start shrinking the fabric, but just a little below the point where it would shrink. This seemed to soften the fabric and make it real easy to pull over the curves. The same thing worked great while applying the pinked tapes. The adhesive you are using is a water born epoxy and has to have heat to kick it over. In my tests, I could get about as good a bond by long heating at a temp just below where it started shrinking as I could at a high heat. Takes lot longer when you have a tube under the fabric as it is a great heat sink. A good thermal thermometer will come in handy also.
Just don't get in a hurry.
The Oratex fabric and tapes are far more forgiving than anything you have ever used. Take a look at my video of me taking off a tape and replacing it with a new one.
http://www.youtube.com/watch?v=efFLc86e_TU
Good thing I was better at covering than I was at making a video.
The hardest place to put a tape on is at the base of the vertical stabilizer where it meets the top stringer. I was unable to do this with one piece of tape. I finally cut short lengths of tape and just laid them over each other. I am sure there must be a way, but I have not figured it out yet. The finished tapes are almost invisible anyway so it was no big deal.

Covering aluminum is another thing. The alum should be primed first or the adhesive does not adhere nearly as good. Then apply adhesive to both the fabric and the metal. Let dry for a day and iron on the fabric. It will look perfect. Let it cool down over night and there are bubbles all over it. Turn your iron up to where you would shrink fabric over metal and start ironing it down again using release paper of course. If you don't use the release paper, you might get the paint so hot, it will stick to the iron. Follow right behind the iron with a damp cold towel and set the adhesive.
the next day, you might have one or two small bubbles, but you can work them out. The Oratex fabric does not let the air out like other fabrics do and it takes a little work. I was able to cover the nose bowl on my plane and all of the cowl and belly pans. No bubbles. However if you do need a hole in the metal you have covered, drill it from the back side, not the fabric side. You will end up with fine alum shavings under the fabric around the hole if you try drilling from the front. This fabric is tough and it is even hard to drill through.

I did not tape all the places the fabric touches tubes like I would do with other fabric. It is so easy to apply, I thought I would wait and see if I would ever need it. After all this is a experimental airplane. What good is it if we don't experiment.
 
While I have no experience with the Oratex fabric, other than when Lars showed it to me at the AK Airmen's show last spring, I can say that I have known Lars for a number of years, and the guy is very knowledgeable and extremely honest. If I end up building up an experimental one of these days, I will be using Oratex.
 
What about "overheating" of the fabric and losing tension as is possible with the certified or "other" polyester or Dacron fabrics.

I have seen this often on model airplanes.......guys get the stuff too hot with the heat gun.

Has this been looked at or experienced with Oratex on fullscale airplanes?? Thanks.
 
What about "overheating" of the fabric and losing tension as is possible with the certified or "other" polyester or Dacron fabrics.

I have seen this often on model airplanes.......guys get the stuff too hot with the heat gun.


Has this been looked at or experienced with Oratex on fullscale airplanes?? Thanks.

I did not see it Dave, but that does not mean it could not occur. If you do the calibration that I described at the beginning it will not happen. In doing some expermenting, I did get some tapes so hot that the pinked edges started to curl up and turn under, but never tried to just overheat the fabric. I can say that it does not react like normal fabric, nor does it shrink as much. I wish Lars would jump in here and answer some of the questions I have not run up against yet.
 
I did not see it Dave, but that does not mean it could not occur. If you do the calibration that I described at the beginning it will not happen. In doing some expermenting, I did get some tapes so hot that the pinked edges started to curl up and turn under, but never tried to just overheat the fabric. I can say that it does not react like normal fabric, nor does it shrink as much. I wish Lars would jump in here and answer some of the questions I have not run up against yet.

Hi Folks,
The common well known Overheating-and-then-turning-slack-effect can NOT happen with ORATEX6000 at all. No way in hell. Have tried, and tried again. It will start to get discoloration blemishes if you get it too hot with an Iron, and it will then ultimately melt beyond 250celsius, about 482 Fahrenheit. BUT I have set my heat gun permanently on 480 Fahrenheit and never get anything bad with that, even up close! I guess the meltdown is actually beyond 500 Fahrenheit.
Having a good heatgun with digital readout is essential.
And this Oratex6000 can be stretched again and heated and shrunk again, it does not seem to tire of it ...
Best Regards,
Lars
 
Thanks Lars, that is a test I had not run. I know you need a good pair of leather gloves when working with it or you can really burn your hands. Found out the hard way.
 
Lars, Will you be at OSH this year? Is there anywhere in the states where you will demo Oratex this year?

Jake
CC EX left wing almost done.
 
Thanks Lars

I guess "calibrated heat gun" is not a term that is in my universe.:D

Thanks again. D

Hi,
Heck, I just say you need a good quality heat gun, with a digital temperature readout, will cost you maybe $150 but is well worth it in the long run. And you have to get a $86,- at sears infra-red Thermometer, to check your surface temperatures. And you just get a good hot iron and after you figure it out once you mark the dial on your iron Yourself, then You have your "Calibrated Hot Iron".
Very easy and you dont need to go Rogers way of ordering the german iron... THAT german Iron was supposed to have a switch on the back that would allow it to run on USA housepower and it should not have needed the 110 to 240 Volt converter! - I will ring someones neck in germany for sending Roger an Iron that needed a Converter! (Roger; Sorry 'bout THAT!)
( I really should try to write with a German Accent)

And Yes sure I be in Oshkosh again and will do a demo !
 
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Thanks Lars, that is a test I had not run. I know you need a good pair of leather gloves when working with it or you can really burn your hands. Found out the hard way.

Yeah if you dont burn your finger at least once it wasnt hot enough! I use good leather gloves and then there are no worries! I should say a word about the tools of the trade, it really doesnt have to be fancy.
I use two irons from Garage sales, One is a Big ROWENTA Model DM-252, has 1400W and is Made in Mexico (yikes!). The small one is a Rowenta folding travel iron of 1000W DA2519054200 (Made in China! =worse).
The Heat gun was $150,- and is a BOSCH (yes Good Better -Bosch) and is named 1944LCD. Rumor has it that it was just TOO GOOD and therefore was taken out of production!
Lets see if I can upload a picture ( hate computers )
Alright, the heatgun in the picture is very similar...The long-handle iron in the picture I would call BAD , I dont like them! They seem to have hot spots and uneven heat and do not keep the temp stable, and I think they are uncomfy with the long handle, But anyway folks get NICE results even with these Irons...
regards From Anchorage,
Lars
 

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Lars, the Iron had a switch to use it on 115 VAC. But it had that funny Europe Plug on it. I had to order the adapter plug. Great Iron for 35 dollars. Should ship a bunch in. Better than most US irons I have used and nice and small.
 
I was able to cover the nose bowl on my plane and all of the cowl and belly pans.

Why would you bother to cover metal parts rather than paint them?

How are you reinforcing for inspection covers? What are you using for rings and how do you cement them?
 
Why would you bother to cover metal parts rather than paint them?

How are you reinforcing for inspection covers? What are you using for rings and how do you cement them?

I cemented the plastic rings on with Stewarts cement and then covered them with Oratex.
I wanted the metal parts to match the fabric and had never tried covering them with fabric. The 600 fabric is real light and it really looks great covered. Matches in texture as well as color. A lot easier than preparing the metal, and painting. After 8 years on my plane with painted metal, I have some corrosion around the screws. Don't think it will happen on this.

I covered the window trim pieces with vinyl that matched the powder coating. Sure cheeper than buying matching paint.

I always figured on a experimental plane, we should experiment, plus I hate doing things the same all the time. Never get any smarter, but I am having trouble with that anyway.
 
Yet it cannot be peeled off.JPGNot enough Glue was used.JPGToo much glue&on there for good.JPG
How are you reinforcing for inspection covers? What are you using for rings and how do you cement them?
Hi,
We use Superglue to glue on inspection rings and grommets and drains
and vents...such as on the trailing edge undersides. Please see here attached some demo with the Superglue and the Inspection-hole-re-enforcement-ring...The Fabric glues well to itself with the Oratex Glue and it can also be glued to rigid structures with Superglue (Cyanacrylate), as long as the area to be glued is small. Also we use this type of glue to adhere it to concave structures. The possibility to use Superglue on the fabric is without any drawbacks and makes it EXTREMELY easy to glue on repair patches in the field (in our case the deep bush)...When glue-ing on a patch with superglue the glue has to be as thin as possible so it remains flexible enough on the flexible fabric-to-fabric bond.
In general our proprietary glue is much stronger than superglue in the fabric to fabric bond and in the glue-ing the underside of the fabric to something. But on the topside of the fabric the Superglue works so well that you would break the inspection ring to pieces when trying to peel it off. I did some experiments with that and the rings are definitively on there for ever! Even the broken pieces are still stuck to the fabric. If you would somehow break a ring on a real plane you could fix it by using more superglue and by gluing a second ring underneath to reinforce the first, broken one on top. The usual practice of putting a doily, a doubler out of fabric, on top of the reinforcement ring seems to be
technically unnecessary. Many might do it just to preserve the traditional look.
The Photos show:
In the middle not enough glue was used and there is a void at the edge of the ring.
On the right too much glue was used and there is a halo of glue around the ring, but that doesnt hurt a thing.
On the left it just shows that even when grabbing underneath the ring-edge and pulling UP the ring does not come off. The pulling it up can be continued to the point that the ring brakes, but it will stay attached.
 

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Lars, the Iron had a switch to use it on 115 VAC. But it had that funny Europe Plug on it. I had to order the adapter plug. Great Iron for 35 dollars. Should ship a bunch in. Better than most US irons I have used and nice and small.
Hi Roger,
Glad to see that you liked it and it worked out for you. I was worried that it was more a headache than it was worth.
 
Hi Rob,
Please say do you have the Oratex UL600 or the Oratex6000 on it and what color is it?
Would like to know...
Regards from Anchorage,
Lars

Hi Lars,

I *think* you know the cub pretty well. and I *think* it is all 6000 including the tapes. It is yellow, and I didn't mean for what I wrote to come across critical to either the product, or the cub in particular. Just some observations from the casual time I've spent around it.

Am I right in assuming there is not a difference in tapes such as the 'straight' and 'bias' tapes of Ceconite? and if so can a guy manipulate the 600 tapes better for use in compound radius areas?

I will shoot you a PM, or email, as I am starting to fall behind.



Take care, Rob
 
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