Mike,
When we were preparing to close out our wings we had the same questions. At that time Lancair was recommending a Hysol adhesive with a surprisingly low peel strength that they no longer recommend.
I’m certainly not an expert on epoxy adhesives – just my thoughts on where I ended up on this.
The Hysol 9430 appears to have very similar properties to the 9360. The 9430 is a general industrial formulation tested to industrial standards from their industrial group in Connecticut. The 9360 is from their aerospace group in California, formulated for aerospace applications with testing to aerospace standards – usually more demanding. I haven’t studied the differences in these standards, though. The referenced standards are listed in the attached Hysol/Loctite information sheets and can probably be located on line.
My wife and I decided to use the Hysol 9360 formulation – and yes, it’s blue in color where the 9430 is grey.
Valin Thorn
Legacy Project
Boulder, Colorado
From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Mike Baudhuin
Sent: Wednesday, August 14, 2013 5:52 AM
To: lml@lancaironline.net
Subject: [LML] Wing closing epoxy
I am preparing to close a set of wings and have some questions about Hysol epoxy. I've reviewed previous posts and there hasn't been much said for awhile, perhaps because wings are coming from factory closed now.
I went to Aircraft Spruce and said "I need six quarts of Hysol." They sold me six quarts of Hysol. I used it to epoxy in a fuel drain and probe and was asked by Matthew Colliers why it wasn't blue. So, I looked closer at my manuals and saw that it calls for epoxy and flox if temperatures are below 70 degrees and Hysol 9339 if temperatures are above 70 degrees. I then went to the Lancair website and found they don't even carry Hysol 9339, but have changed to Hysol 9360. The product Aircraft Spruce sells is Hysol 9430. Lancair tech support says they don't know why 9360 is specified. "That was selected by the guy before me."
"This new and improved Hysol glue replaces the old EA-9410-2 glue. EA-9430 has the same characteristics as the EA-9410, but has a 50 minute pot life instead of the 30 minute pot life of the EA-9410 at 77°F. Used extensively in the Strojnik S2A sailplane and many other homebuilts."
Locktite tech support and the data sheets show the pot life, tensile and shear strenght to be almost identical. The one difference I can find is that the 9360 specifies shear at different temperatures while 9430 specifies the shear strenght only at 77 degrees. The guy from Locktite couldn't explain the differences, and said "they appear to be very similar products". Can anyone tell me what makes the 9360 product better suited for Lancair wings? Is there a reason not to use the six quarts of 9430 in my fridge? |
Mike Baudhuin