Mon Sep 07, 2009 11:30 pm
James, it seems that this issue could in fact have some effect in Europe at least, this from a mutual acquaintance, who I hope won't mind me posting it:
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We flyers of old aircraft do have very much of an interest in what you are doing. The reason for it is very long in the tooth. The EASA as they are now known, have produced a list of aircraft that do not have to be maintained to their standards. It is in euro speak called Annex II aircraft. The complete list is on the link below:
http://www.easa.eu.int/ws_prod/c/doc...5-Feb-2008.pdf
The people in Brussels have agreed that AC 43-13 is the only way to keep these aircraft airbourne. So they have agreed that AC 43-13 is the only way forward for these airframes if they are not to disappear alltogether. They will be on what in euro speak is called "Permit to Fly" but they will be flying on something very, very close to the American Experimental cat.
If you can get West System into the AC 43-13 (even if it is an Advisory in America it will mean a lot more to us in Europe), then the horizons are very bright for us guys in Europe having to everything by the book!
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We flyers of old aircraft do have very much of an interest in what you are doing. The reason for it is very long in the tooth. The EASA as they are now known, have produced a list of aircraft that do not have to be maintained to their standards. It is in euro speak called Annex II aircraft. The complete list is on the link below:
http://www.easa.eu.int/ws_prod/c/doc...5-Feb-2008.pdf
The people in Brussels have agreed that AC 43-13 is the only way to keep these aircraft airbourne. So they have agreed that AC 43-13 is the only way forward for these airframes if they are not to disappear alltogether. They will be on what in euro speak is called "Permit to Fly" but they will be flying on something very, very close to the American Experimental cat.
If you can get West System into the AC 43-13 (even if it is an Advisory in America it will mean a lot more to us in Europe), then the horizons are very bright for us guys in Europe having to everything by the book!
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Tue Sep 08, 2009 5:56 pm
TriangleP wrote:airnutz wrote:JDK wrote:I understand that the West System is being used at the RAAF Museum for the static restoration of the Mosquito PR.XVI, and also on Project 2014 building a replica Bristol Military Biplane (or Boxkite) to fly.
www.boxkite2014.org
Dunno if this data adds any weight to US legislation process, Andrew. Your call?
If I remember(alarm bells)...correctly, Glyn Powell chose the West System epoxy for his Mosquito
replications.
airnutz,
I inquired on Wings OverCambridge forum regarding Glyn Powell's KA114's glue and got this friendly and helpful reply from "Bruce", a major league poster on that forum, and apparently knowledgeable. Only the constructor could verify, which I've tried but no reply...
I have a friend who helped build the Wing at Drury, he says that it uses modern, approved epoxies. There are 2 types used depending on the components. West System was used around the fuselage but the wings mainly used Araldite, primarily because KA114 is likely to be repainted in camouflage rather than silver, and the Araldite better handles the higher temperatures that will produce.
http://rnzaf.proboards.com/index.cgi?bo ... 346&page=3
Ahh! Thanks TP! I had gone back to the Mossie pages and couldn't find it again...it's been years ago when I first read it.
Tue Sep 08, 2009 8:12 pm
I built my first "stripper" canoe using West epoxy in 1987. Since then I've built about a dozen boats, plus many repairs.
It's good stuff, used properly, but it's not magic.
In fact, it's brittle, when mixed pure. If you let a cup of it harden for a week, chill it, then set it on a concrete floor and whack it with a hammer, it fractures like glass.
I mix it with micro-fibers, or an equivalent, to give it body. Then it has more strength -- it's much more tied-together.
I wouldn't use it pure in a structure that I wanted to have flex strength.
No quantified data gents, but I've been mixing it up for 23 years.
Dave
It's good stuff, used properly, but it's not magic.
In fact, it's brittle, when mixed pure. If you let a cup of it harden for a week, chill it, then set it on a concrete floor and whack it with a hammer, it fractures like glass.
I mix it with micro-fibers, or an equivalent, to give it body. Then it has more strength -- it's much more tied-together.
I wouldn't use it pure in a structure that I wanted to have flex strength.
No quantified data gents, but I've been mixing it up for 23 years.
Dave
Thu Sep 10, 2009 9:43 am
All epoxies are brittle, especially when cold. That is generally why they aren't used in large blocks. Once fibers are introduced, the fibers limit the strain enough to prevent the type of fracture you describe. Epoxies can also embrittle and shrink with age and environmental exposure over the years as they continue to cure. This can lead to microcracking of the resin which reduces strength and allows the intrusion of moisture.