brainfart

This video and the jamesandersson.com web site were created by a German TV show doing an experiment on the spreading of rumours, viral marketing etc.

MSDS for resin and hardener. Nothing special in there. I wonder why other formulators do not market their own, maybe slightly altered versions of these expensive and successful resins? si_en_LH385.pdf si_en_LR385.pdf si_en_hardener386.pdf

MGS is introducing a new resin system: MGS LR385 + LH385 + LH386. Seems to be the non-toxic, non-hazmat version of the very successful MGS L285 range of resins and hardeners. Here is the data sheet. td_en_LR385_eng_041108.pdf

> Well as I mention earlier... going rotary would be for safety reason... nothing else... Uh oh... wrong answer.

Having a background in chemistry I have to give my 2 cents worth: I'd rather use a volatile solvent, because it's volatile! Meaning it will evaporate without leaving any residue whatsoever. Even when you use an alcohol (alcohols are bad for epoxies on long term exposure) it will be gone just seconds or a minute after you're done wiping off the glue, and your epoxy will not be affected whatsoever. When using solvents with higher boiling points like the aforementioned eucalyptus oil or others like orange oil which seem to become rather popular lately for environmental reasons these oils will leave some residue on the part for much longer, meaning that residue has time to migrate into the epoxy. These oils usually have boiling points in excess of 200°C. They do not evaporate easily! And since they aren't water soluble you cannot easily wash them off with water (like you can with acetone or alcohols). Does all this actually matter? Probably not. I'd still rather use a rag soaked in acetone, wipe that stuff off and not worry about the epoxy being contaminated by a persistent solvent.

Of course I've never seen any of those 6 month planes, but I assume that not only were they built by competent and experienced people who didn't spend half their time scratching their heads trying to make sense out of the plans and descriptions and the other half daydreaming about what they would do once their toy was finished, they probably also didn't care a whole lot about the optical appearance of their baby. Todays builders usually try to achieve a car-like perfect finish and an interior which is superior in appearance to their living rooms. Don't strive for perfection, just build (and fly) it!

http://www.austroengine.at/products/jet-a1-piston-engines/piston-engines.html http://www.austroengine.at/cms/upload/AE_300_Technical_Data.pdf

Seen in a German aircraft magazine: Diamond http://www.diamond-air.at/ will soon start producing their own diesel engines after Thielert went belly up and the supply of new Thielerts has ceased. They apparently have lots of aircraft without engines in stock... Long term testing is almost finished and the engine is currently awaiting certification. It is based on a turbocharged Mercedes Benz 2L diesel engine currently in production. Weight is higher than the Thielerts, but allegedly power output is better and fuel consumption will be lower, too. Engine will be made available to other aircraft manufacturers. TBO 1000h, plans are to raise this to 2400h. Engines will be overhauled, not changed out like the Thielerts so they will become available to everyone even if Diamond refuses to sell them. Current Diamond owners with diesels will have the option of upgrading their aircraft to the new diesel.

They indeed use spark plugs since the compression isn't high enough for self-ignition of the diesel. They claim the engine can be adapted to other fuels, like gasoline, alcohol, vegetable oil, kerosene etc. They will build a few prototypes, further development and production needs to be financed by investors. There is an American investor who financed part of the development and wants to use the engine for generators for military purposes. They also mention converting the engine for light aircraft use, but apparently that's not their main priority (ultralight aircraft in Europe are comparable to LSA aircraft in the US, so I assume that would be a 100-150HP version).

> found the photo on a German language newspaper web page Post a link, someone will be able to translate it.

http://www.ctmat.de/downloads/Ampreg_20.pdf There is a resin called L 20 which is officially approved for glider construction in Germany (and consequently in some neighboring countries), not sure if this really is Ampreg 20 or 22 or some other resin. Will investigate. For resins to be approved for aircraft construction by the LBA (German FAA equivalent) they need to exhibit, among a whole bunch of other (mechanical) requirements a certain glass transition temperature. For gliders I think this is around 55°C, while for "real" powered aircraft that temperature is around 80°C. That L20 resin is only approved for glider construction due to its Tg. Same is true for MGS L335, btw! (*) Which of course doesn't mean they cannot be used for powered aircraft building outside Germany... just saying. For repairs the rule here is the following: use the original resin... if that one is not known or unavailable, use L285. So most professionals use L285 almost exclusively. The somewhat higher price isn't really a factor considering the lack of hazmat fees. Makes sense to have only one resin in stock and not having to order from abroad. (*) Edit/correction: From the MGS 285 datasheet: "After heat treatment at 50 - 55 °C (122-131 °F), the system meets the standards for gliders and motor gliders (operational temperatures -60°C (-76°F) to +54°C (129 °F). In order to meet the standards for motor planes (operational temperatures -60°C (-76 °F) to +72 °C (161 °F), heat treatment at 80 °C (176 °F) is necessary."

Small amounts of MGS resin and hardener are being sold in polyethylene containers. Just don't store them for really long periods, like over a year and you will be fine. I also use these inserts in plastic bottles, they work great when you need to dispense small amounts of hardener:

Edit: ok, not quite, but close... http://de.wikipedia.org/wiki/Dornier_S-Ray_007 http://www.do-sray.com/ http://www.sfl-gmbh.de/en/amphibienflugzeug.html

Such tapes exist, I've seen them.

I'd definitely do some experiments. Prepare a few test samples of glass and epoxy, prep it exactly as your plane parts, and then apply whatever epoxy you want to use 1) under hot, humid conditions and 2) with air conditioning and low humidity and see if there is a difference. When I took classes at a local FBO(?) for my composite repairman certificate temperature and humidity were constantly measured and recorded inside the working area. This data became part of the repair report. MGS and all the other suppliers of epoxies which are certified here for aircraft building and repair all give limits for maximum allowable humidity. I have also discussed the effects of humidity in the past with an acquaintance who owns a composite business and who is a contractor for EADS, has built parts for satellites and was involved in building the ETA (the worlds biggest glider). He had to install extensive air conditioning because without it parts made in summer, during high humidity periods were clearly inferior and often unusable. All the aircraft manufacturers I have visited used air conditioning where composite parts were being made. And this despite Germany having much different, more favorable climatic conditions than Texas. Maybe I am barking up the wrong tree here, so let's hear what others have to say.

So he broke another nose wheel?!? Reykjavik is in Iceland, not Greenland...

Some epoxy RESINS might start to crystallize during storage, especially when exposed to low temperatures. This is not a reason to discard them, it's merely one of the components (bisphenol A diglycidyl ethers) separating from the mixture. By heating up the resin in a water bath and stirring and shaking the crystallized component can be redissolved and the resin will be good as new. This is not valid for epoxy hardeners. If they show crystallization they most likely have reacted with carbon dioxide and should be discarded. They too might be ok and it might just be one of the components crystallizing, but most of the time it's a sign of them having gone bad so it's better to be safe than sorry and throw them out.

> I think I have to throw out about 4 gallons of un opened MGS 235 and > hardener. It has never been opened but it is about 4 years old. Should I keep > it or toss it? There's no need to throw it out. The resin can be stored for many years and will still work. The hardener might be affected, depends on the packaging. Is it in plastic or metal containers? What does it look like? Did anything crystallize out? Has the colour changed? The amines need carbon dioxide and water to go bad. If no carbon dioxide or water can get into the container then the amines will not be affected. Discolouration might occur but it will still work. Once the hardener container is opened I wouldn't store it for years, but when originally packaged and well sealed it will last a LONG time. I've personally used some other MGS resin which was over ten years old and it worked like new, even though the hardener had turned reddish colour (which disappeared when it cured). Of course, if you have any doubts buy new. Your life might depend on it. But experience shows that old epoxy resins still work ok. The reason the manufacturers give relatively short use times is 1) liability reasons and 2) they want to sell their products. They will never admit to you that the resin can still be used. If in doubt, use the epoxy for something else or give it to some boatbuilders or other hobbyists. Or do some tests, but that means opening the original hardener container.

West Systems offers a flame retardant epoxy, Pro-Set 127FR.

> Also, seems it was really hot...and humid....shocking for Houston. Don't work with epoxies when the relative humidity is over 65%. A hygrometer is a must have item in every epoxy shop! I (and others) have mixed feelings about solvent wipes, too. Depending on the type of contamination these wipes might just spread the contamination around even more. Rags exposed to fabric conditioners, room heaters, compressed air etc. are all sources of contaminants which might affect the epoxy bond. > Epoxy works fine for a few days, but alcohol in the fuel softens epoxy formulations over time. > I have no idea what/how Jeffco is made. > Pro-seal has been used in fiberglass tanks as well There are no wonder epoxies, they all work according to the same principles, most have substantial similar lists of ingredients anyway and many of them are pretty fuel resistant (especially the cheaper, higher viscosity non-laminating resins without added reactive diluents). > I'm investigating a top/final coating of vinyl-ester resin in my fuel areas. > Compatibility with epoxy/cloth layups unknown Epoxy adheres well to polyester and vinylester, but adhesion of these resins to cured epoxy is poor.

> The answer to your question is that we are not that kind of Cozy It was a rhetorical question, but thanks anyway. (Seeing how good humoured chrissi usually is, I figured she wouldn't take that question the wrong way, which she hopefully didn't. Again sorry if I offended the both of you.)

Sorry, I remembered them making the same kind of 'joke' before. My apologies.

There are more pictures including the pointy nose at http://mojaveskies.blogspot.com/ Very interesting pictures. Are they selling plans already? I:p

Dumb beginner question: Just how cozy are these grrls, anyway? Sorry couldn't resist.

If you want to reduce waste, weigh it! I bought myself two little electronic scales from a dealer I found on ebay. One has a capacity and resolution of 50g/.01g, the other one 600g/.1g. Price was only about €10 each (these are the same kind of scales that West System charges you $40 for). One might say the smaller one is too accurate, but I need the accuracy for other uses anyway and I actually use that one all the time. Accuracy and linearity were checked against an expensive electronic analytical scale at work and they are remarkably good, but even if that wasn't the case it would still work since it's the ratio of the ingredients that counts here. Most of the time I just need 2 to 5 grams or so of epoxy for small repairs or gluing something. I use disposable plastic shot glasses and wooden coffee stir sticks (lifetime supply of 1000 pcs. for 3 bucks) and can accurately weigh such small amounts without having to worry about the correct ratio anymore. In the past, when I used the cheapo electronic kitchen scale (2000g/2g) I had to prepare at least 20g and still wasn't sure if the ratio was right since that thing was so damn inaccurate. Good enough if you want to mix a pound of epoxy, but completely useless for small amounts. The resin and hardener are dispensed dropwise with disposable 3ml plastic pipettes (bought a box of 500 years ago, another lifetime supply): After use place them upright on a pice of tissue and since they are made from nonwetting polyethylene they will completely drain, or just leave what little is still in there for the next job. Some might say I'm ridiculously anal but considering the amount of money saved and how much epoxy I do NOT needlessly throw away anymore I think the small investment into accurate electronic scales is well worth it. And what's even more important, I now know for sure that the ratio is right, no more guessing and worrying.