bacon Posted January 2, 2012 Posted January 2, 2012 Was wondering if anyone here knows off a accurate way of testing if dacron skins are still safe to fly with. I've found a few articles about a tester that quicksilver sells to test there dacron with but cant find out were to buy one from. Any help would be awesome thanks Bacon
pudestcon Posted January 2, 2012 Posted January 2, 2012 What you are looking for is a Bettsometer. The attached pdf has a link to a supplier in the UK - look under tools in the 'shop'. You could try the shop here- send Ian (Admin) a PM and he will tell you if he can supply or not. SB-007 Issue1 Bettsometer.pdf SB-007 Issue1 Bettsometer.pdf SB-007 Issue1 Bettsometer.pdf
hihosland Posted January 2, 2012 Posted January 2, 2012 you can do your own test with a 0.2mm round bodied needle ( I've forgotten the gage equivalent ). Pierce the fabric with the needle and then pull along the surface of the fabric with a spring balance, if it does not tear with a 1kg pull parrallel to each direction of the threads then it is OK. That is the UK pass/fail test for the weigh of Dacron that covers the Skyranger, and is the basis of the Betsometer test device. The Americans use some other system. best of wishes David Hill
Riley Posted January 3, 2012 Posted January 3, 2012 Was wondering if anyone here knows off a accurate way of testing if dacron skins are still safe to fly with. I've found a few articles about a tester that quicksilver sells to test there dacron with but cant find out were to buy one from. Any help would be awesomethanks Bacon Rather than to spend a fair bit of money (that could be better spent on fuel) for a tool that you probably won't use again for 10 years, under threat of piercing both your eyes with a sharp stick and hanging a building block from your nether regions if it's not returned, I'm happily to loan you a Bettsometer to do your testing. You cover the cost of posting both ways and.... insure your vitals should it get lost. Get in touch if you can't find one closer to home. cheers Riley 9
Guernsey Posted January 3, 2012 Posted January 3, 2012 Rather than to spend a fair bit of money (that could be better spent on fuel) for a tool that you probably won't use again for 10 years, under threat of piercing both your eyes with a sharp stick and hanging a building block from your nether regions if it's not returned, I'm happily to loan you a Bettsometer to do your testing. You cover the cost of posting both ways and.... insure your vitals should it get lost. Get in touch if you can't find one closer to home. cheers Riley Ian (Admin) give that man a Trophy, a true family Forumite. Alan.
Guest Crezzi Posted January 3, 2012 Posted January 3, 2012 The Americans use some other system. the Maule Fabric Tester is more commonly used in the States - I believe Aircraft Spruce sell them. If you want to buy your own bettsometer rather than borrow Rileys, I think Airborne now sell them in Aus. And you should really do the test a lot more frequently then once every 10 years ! Hope that helps John
Suitman Posted January 12, 2012 Posted January 12, 2012 What you are looking for is a Bettsometer. The attached pdf has a link ... Hey Pud, did you notice that in the document it states ... "To remove more stubborn oils, use ethanol such as methylated spirits (or vodka / whisky etc). " .... I can hapily report that after NYE, I have no stubborn oils in me. Peter 5
Tomo Posted January 12, 2012 Posted January 12, 2012 If you can push your thumb through it, it's had-it!
farri Posted January 15, 2012 Posted January 15, 2012 If you can push your thumb through it, it's had-it! Tomo, that`s not silly! I`ve got my own way of testing the fabric and it`s none of the above. I know a guy who purchased a used Drifter, flew it a long way to get it home and when he got home, used the thumb test, just above the leading edge of the wing and his fist went through it. Frank.
bacon Posted January 15, 2012 Author Posted January 15, 2012 Luckily im getting mine deleivered . Get to test it before i have to fly it, the bloke im buying it off has no problem with flying it but i will feel much safer if i test it out before I go for a fly. Thanks everyone for the replies Ive got a Bettsometer in the post at the moment, thanks heaps to riley for his generosity. Ill give it a test with it and the thumb test. Has anyone heard of dacron covers giving way in a great hurry or do they usely rip then stop?Would be in a bit of trouble if you were flying around and all of a sudden had a big rip in your main wing cover. Bacon
farri Posted January 15, 2012 Posted January 15, 2012 Anyone buying a used Dacron covered aircraft should test the fabric before buying it, if not, definitely before flying it home. Seems obvious doesn`t it?...Apparently, not to everyone. Frank.
Vev Posted January 15, 2012 Posted January 15, 2012 I found this an interesting video from EAA. http://www.eaavideo.org/video.aspx?v=666091412001 Cheers Vev 2
dazza 38 Posted January 15, 2012 Posted January 15, 2012 I found this an interesting video from EAA.http://www.eaavideo.org/video.aspx?v=666091412001 Cheers Vev Thank you Vev.That was very informative.I didnt know that dark coloured Dacron lasted longer than light coloured dacron.I though it would have been the other way around.
bacon Posted January 15, 2012 Author Posted January 15, 2012 Tomo, that`s not silly! I`ve got my own way of testing the fabric and it`s none of the above.I know a guy who purchased a used Drifter, flew it a long way to get it home and when he got home, used the thumb test, just above the leading edge of the wing and his fist went through it. Frank. What's your way of testing frank?
farri Posted January 16, 2012 Posted January 16, 2012 What's your way of testing frank? Hi Bacon, I suspected someone would pick up on what I wrote. I make the skins for my Drifter and the reason I said it was my way of testing, is because it is, my way, of testing.... Hasn`t failed me yet and I`m on my third set of skins. I`m not trying to be a smart rrrrsssss, I just don`t want some else to do what I do, get it wrong and get hurt. What Tomo has said, ( If you can push your thumb through it, it's had-it! ), is fairly accurate, however, everyone has different levels of strength, therefore, a different idea of how much pressure to apply. Though the fabric may be ready to fail, someone with little, or no experience with dacron, could apply too little pressure and assume that the fabric is just fine. If the fabric is extremely faded, chances are, that it has also lost most of it`s strength. Frank.
bacon Posted January 16, 2012 Author Posted January 16, 2012 Hey frank Now I got ya I wasn't sure were you were going with your comment all makes sense now lol. That's what i was thinking with differnt levels of strength everyone would be different i guess the real question is. Is it possible to be pushing to hard? Im guessing brand new dacron you just wouldnt be able to penetrate it with your thumb no matter how much you push. Cheers Bacon
farri Posted January 16, 2012 Posted January 16, 2012 Hey frank, Is it possible to be pushing to hard? Im guessing brand new dacron you just wouldnt be able to penetrate it with your thumb no matter how much you push. Cheers Bacon Bacon, ( L0ve the user name , Hang on!.. Is that just your user name? ).... I gues it depends on how strong the pushers thumb is! . Seriously!.... The strength of the fabric needs to be proportional to the wing loading.... If the fabric is weaker than the wing loading, then it could fail!... If not in still air, then in turbulence. Frank.
Tomo Posted January 16, 2012 Posted January 16, 2012 Don't forget to test on top of the wing, not underneath!
bacon Posted January 20, 2012 Author Posted January 20, 2012 Got too test the dacron today it all passed the thumb pressing test. I also tested it all with the bettsometer and all passed except the ailerons, Which I tried to push my thumb through and couldn't gunna get wayne fisher too make me some new ones up anyway better to be safe then sorry. Nothing better than having your own plane to go fly when ever you wont!! Bacon
Riley Posted January 20, 2012 Posted January 20, 2012 Hey Bacon. I checked with that geezer re the used aileron skins & he wants to keep them with the wings as a replacement set just to ensure that he'll never need them. Guess you gotta help Wayne buy a Mercedes (just kidding). Cheers Riley 1
Patrick Normoyle Posted June 16, 2012 Posted June 16, 2012 If you can push your thumb through it, it's had-it! Tomo got it in one, you were born with two testing devices and as long as you still have two hitch hikers tools aka, thumbs, your set, best place to test is near a rib, an inch or so away from the stitching, press down nice and hard, if you go through, you don't go flying until you re-skin, if you don't, your right.
Louis Moore Posted June 16, 2012 Posted June 16, 2012 I used to Maule fabric tester on aircraft I was inspecting, and the "rule of thumb" is really accurate, I could tell by the feel of the fabric under my fingers, how taut it still was, the sounds of it etc... if it would fail before I even bothered pot marking it with the tester! As a side note, you know you have done it wrong when strips of fabric tear of in flight!
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