Roger Mann is building a new, affordable Ragwing ultralight.

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Dillpickle

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Joined
May 3, 2014
Messages
330
Location
Piny Woods, Tx
“Flying a trike is WORK,”.

IMHO. This tells me you are doing it wrong.

Would you like to discuss trike versus airplane flying?
Not really. I found the control lag annoying, particularly for the low level yank and bank that i find the most fun kind of ul flying. And maneuvering the bar, particularly on a tandem, required far more strength than the finger grip on a control stick. Doing It wrong? Maybe. And stol? All the trikes Ive flown required more takeoff roll than SOME of the ultralight. Regardless, not too many guys are building their own trike wings.
 
Joined
Aug 7, 2019
Messages
314
Location
Harleysville, PA
Gorilla glue is a moisture cured polyurethane. That means moisture in the air reacts
to form trillions of bubbles in the glue causing it to essentially become a FOAM when cured. Ask yourself how strong air bubbles can be ? The rule about glue is it can be used when the cured component is stronger than what it is attached to. ie. ok to use when gluing foam or fabrics etc. NEVER use on a structural joint ! I dont know how Gorilla glue gets away with their advertising claiming "worlds strongest glue" Even Roger Mann does not use Gorilla glue on the "main" structural joints.
Many years ago I had an in person loong discussion on gorilla glue with Roger. He had a pile of anecdotal data to support his application. My concern was reversion of the polyurethane over time. After a career in adhesives and materials development I would not use in an airplane but ultright/experimental is where we are...
 

TFF

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Joined
Apr 28, 2010
Messages
17,927
Location
Memphis, TN
My operational concern is who gets it next? Five years or less, it’s going to stay together. 20 years when someone buys it and thinks it’s ok and it crumbles. Hopefully not in the air, or just ripping someone off on condition during a sale.

I still have some of my earliest RC planes I built in about 77-78. Most of the glue joints are ok. A few would need repair to fly again. They are not carrying people. Furniture that stays inside can last forever. Swings in temp and humidity along with vibration and rough handling gives me pause.

Different if it was like Ray Stits experimenting with Polyfiber until it’s right. If someone built a case with proof, I could change my mind, but blind, no way.
 

Victor Bravo

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Supporting Member
Joined
Jul 30, 2014
Messages
11,368
Location
KWHP, Los Angeles CA, USA
After a career in adhesives and materials development I would not use in an airplane but ultright/experimental is where we are...
Forgive the intrusion, but with a background like that you might be in a good position to perform some tests, gather some data over a period of time, and create a proper study of this glue that gives a "better than anecdotal" answer. It would be a great service to E-AB builders, possibly save people's lives, or possibly show this adhesive to be usable.
 

TFF

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Joined
Apr 28, 2010
Messages
17,927
Location
Memphis, TN
The problem is the cheapest plane usually goes to someone who knows nothing except they bought a cheap airplane.

There are a lot of brands that are getting hit by aging aircraft issues. People use to strip a fabric covered plane every five years. Today people cry that they can’t get another five years out of a forty year old covering job. Rusted wing strut AD was because people were not scraping parts because of airplane value. The helicopters I know have a bunch of bottom feeders that blame the company that stuff rusted and delaminated blades though on 50 year old parts left outside the whole time.

The problem is can you put your finger on when it’s dangerous?
 

ToddK

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Supporting Member
Joined
Jan 13, 2016
Messages
801
Location
Shweaty Texas
I suspect that the polyurethane glue will hold up just fine for the average life of a homebuilt ultralight. I am also inclined to thing Roger knows what he is doing, especially for HIS airplane. He has built more airplanes (all of his own design) then pretty much anyone here, and 100% belongs in the hall of fame, if he is not already.

He also knows most builders will choose T88 and for good reason.

That said, were I allergic to epoxy, my first choice would be fresh Powdered Urea Resin glue and then I would religiously adhere to the time, temp, and humidity instructions. My next choice would be resorcinol.

Ultimately, many wood (certainly not all) homebuilt ultralights tend to not be sold, but hung onto by the builder, then the family pushes it outside where it rots for a while, then it goes onto the burn pile often with less then 500hrs total time of them.
 
Joined
Aug 7, 2019
Messages
314
Location
Harleysville, PA
Forgive the intrusion, but with a background like that you might be in a good position to perform some tests, gather some data over a period of time, and create a proper study of this glue that gives a "better than anecdotal" answer. It would be a great service to E-AB builders, possibly save people's lives, or possibly show this adhesive to be usable.
VB, I have thought about that many, many times. To make the data valuable would require a very large test matrix. With the large variations in wood to be used for adherends it would be a report with a very large number of results that cannot be tied directly to the purpose of the test. Also, since few airplanes ever see "boiling" conditions I would be more interested in long term deterioration due to humidity/ thermal (freeze/thaw) cycling. All that is possible but, In my opinion, there is no accurate and clearly corelatable way to accelerate conditioning.
I'll keep thinking on it though and if I do it will include gorilla and both titebond II and III
 
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