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
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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