Rebuilding ailerons.

[Ragwing nut]

Re: Rebuilding ailerons.

I'd be very careful about recommending T-88 for use on a certified aircraft. The max temp that T-88 is recommended for is 119*F, and at 140*, it has a strength of less than 1/3 of that of wood. According to a few different sources, Dupont being one, a black aircraft on a 70* ramp can have surface temps above 180*, while a red aircraft on a 70* ramp can have surface temps above 160*. There's more than one aircraft that I know of that have used T-88 successfully, and more than one that I know of that have had problems. The old Casein glue as well as Resourcinol lose no strength under the same circumstances. I don't understand why one would want to chance it with T-88. One Tiger Moth that I know of, has a thermocouple up in the wing, with a corresponding temp probe and a restriction of internal temperature for takeoff..... not convienient. The guy to talk to about this stuff is Jeff Morfit, Project manager for general aviation at the Seattle ACO.
John

Waco factory actually got West Systems approved. I love the stuff, lots of bunders that can be added to the resin, works great, but I still WILL NOT use in a structural application. As you mention above, epoxy will soften above 140* and lose alot of strength.

[astjp2]

Re: Rebuilding ailerons.

Wow, everybody is bent out of shape with the T-88 but no one has commented on the FPL16A epoxy.....

[freightpilot27]

Re: Rebuilding ailerons.

Just to throw a craw in your socks, is the DAP Resorcinol approved? Does it come with a 8130-3? doubt it, most people get it from home depot. Tim

P.s. I am just stirring the pot a little here

AC43.13-1B Chg 1
1-4 b.(4) (pg.1-4)
"Federal Specification MMM-A-181D and Military Specification MIL-A-22397 both describe a required series of tests that verify the chemical and mechanical properties of resorcinol. Resorcinol is the only known adhesive recommended and approved for use in wooden aircraft structure and fully meets necessary strength and durability requirements."

I would recommend reading ALL of paragraph 1-4. It does speak about epoxy type adhesives also. And specifically talks about elevated temperatures.



ONE MORE TIME FOR THOSE WHO ARE NOT PAYING ATTENTION......
"Resorcinol is the only known adhesive recommended and approved for use in wooden aircraft structure...."

[astjp2]

Re: Rebuilding ailerons.

AC43.13-1B Chg 1
1-4 b.(4) (pg.1-4)
"Federal Specification MMM-A-181D and Military Specification MIL-A-22397 both describe a required series of tests that verify the chemical and mechanical properties of resorcinol. Resorcinol is the only known adhesive recommended and approved for use in wooden aircraft structure and fully meets necessary strength and durability requirements."

I would recommend reading ALL of paragraph 1-4. It does speak about epoxy type adhesives also. And specifically talks about elevated temperatures.



ONE MORE TIME FOR THOSE WHO ARE NOT PAYING ATTENTION......
"Resorcinol is the only known adhesive recommended and approved for use in wooden aircraft structure...."

You are Wrong with the above statement, the first class I took at UAA's Aviation Maint. programs was bonded structures and there are 3 approved adhesives that meet the 24 hour soak time and were approved by the FAA in 1995 when I took the class. They are Resorcinol, is one, FPL16A (developed by the university of Wisconsin) and Plastic resin glue.

Here is a link of some good looking spars and the referenced FPL16A that the Aeronca guys use. Along with T-88 being mentioned.

http://www.joea.com/phpBB2/viewtopic.php?f=26&t=2333&start=105

Here is a discussion of off the shelf adhesives

http://exp-aircraft.com/library/boyce/glues.html

and here is one on plastic resin:

http://www.aircraftspruce.com/catalog/wppages/weldwood.php

I am not wanting a pissing contest, but there is more out there than what is listed in 43.13. Tim

Did you get the 337 I send you?

[freightpilot27]

Re: Rebuilding ailerons.

You are Wrong with the above statement, the first class I took at UAA's Aviation Maint. programs was bonded structures and there are 3 approved adhesives that meet the 24 hour soak time and were approved by the FAA in 1995 when I took the class. They are Resorcinol, is one, FPL16A (developed by the university of Wisconsin) and Plastic resin glue.

Here is a link of some good looking spars and the referenced FPL16A that the Aeronca guys use. Along with T-88 being mentioned.

http://www.joea.com/phpBB2/viewtopic.php?f=26&t=2333&start=105

Here is a discussion of off the shelf adhesives

http://exp-aircraft.com/library/boyce/glues.html

and here is one on plastic resin:

http://www.aircraftspruce.com/catalog/wppages/weldwood.php

I am not wanting a pissing contest, but there is more out there than what is listed in 43.13. Tim

Did you get the 337 I send you?

Tim-

Got the 337. Thanks! Just what I was looking for.

I read the information you linked in your last post. I agree, there is more information than what is in 43.13. However, I know from experience the FAA will not take forum "chatter" as approved data. Agreed, the Aeronca spars that gentleman has built are very impressive, but using T-88 is a bad idea, and it’s not approved for use in certified aircraft.

Also, the information in your second link backs up my statement about resorcinol glues.

Urea-formaldehyde adhesives (Weldwood plastic resin glue you linked to) is considered obsolete due to possible rapid deterioration in hot, moist environments.

I don't know much about FPL16A adhesive, and can only seem to find minimal info about it. Nothing telling me if it meets any standards.
http://www.aircraftspruce.com/catalo...hughesglue.php (says experimental and homebuilt)

There may be better glues out there (T-88 & Plastic resin glues are not it), But in certified aircraft, according to the FAA, I can find only ONE legal adhesive. If there is a better glue out there, use it, but make sure you can get it approved.

I don't have some other IA to sign my work off, I sign off my own work (and the work of others). I would never sign any wood work off using adhesive other than resorcinol unless the customer had written documentation from the FAA allowing the use of that adhesive.

Where can I find information about FPL16A being approved, or at least the MIL SPECS it conforms too? I am interested in learning more about this adhesive and will be happy to eat my words if it does indeed conform to FAA standards for approved adhesives.

http://www.fpl.fs.fed.us/documnts/pdf1997/vick97c.pdf Still sounds to me like resorcinol glues are the best choice. Why don't people like it? Its easy to work with, its a known entity, and is PROVEN, not just initially, but for years to come under normal and extreme conditions.

[Guest]

Re: Rebuilding ailerons.

fyi- from Ac43.13 par. 1-4 page 3 of chapter 1

(3) Plastic resin glue (urea-formaldehyde
resin glue) has been used in wood aircraft
for many years. Caution should be used due to
possible rapid deterioration (more rapidly than
wood) of plastic resin glue in hot, moist environments
and under cyclic swell-shrink stress.
For these reasons, urea-formaldehyde should
be considered obsolete for all repairs. Any
proposed use of this type adhesive should be
discussed with the appropriate FAA office
prior to using on certificated aircraft.

[Ron Coleman]

Re: Rebuilding ailerons.

Quite a few years ago I saw a high performance sail plane with the aluminum sheeting peeling off of the wings. It had been assembled with T-88. It didn't take to being parked on the hot apron.

Three years ago I helped a visitor pull his home built out of the sun because the cap strips were pulling loose. The fabric was glued to the caps (no other fasters) and the cap strips were glued wilth T-88. After he bought the plane he flew it for a year or so then he painted the wings black! He left the plane sit in the sun before he flew over to the house and he said that he could see the fabric lifting in flight. He rib stitched the wings and flew it the rest of the summer until he landed short into a drainage ditch filled with weeds. He settled just low enough that the landing gear caught the edge of the ditch but the fuse skidded along the ground leaving the gear behind. He might have saved much of the plane if the glue hadn't been weakened by the heat of the sun.

[Ron Coleman]

Re: Rebuilding ailerons.

I have vivid memories of that same airplane driver and his first attempt at manned flight ten or fifteen years ago. It was a cold, miserable, wet spring. All of the fields around us were flooded with melted snow. In some places the water was two feet deep. Luckily, the runway was firm because the frost was not out of the ground, or maybe not so lucky.

This, would be, airplane driver brought out his untried weedhopper with a sick 10 hp. chain saw engine (no wheels) and prepared it for flight. A quick walk around revealed missing screws that held the cover tight and a couple structural cables not connected. There was a strap that went over a tube to hold a sling seat and a plastic clasp from a childs seat that fastened the crotch strap to the overhead tube.

He hoisted that rat trap on to his back, fastened the crotch strap and with engine wheezing away we ran down the runway holding up the wing until he got enough speed to float away. Well, anyway after three or four tries.

I thilnk that he got up about fifty feet before he started to drift to the left out over the flooded field and toward our tree line. I saw him struggling to turn to go between two large trees because he could never get over them.

Suddenly, his arms and legs sprung outwards and the weedhopper pitched up. He had fallen out of the sling and had dropped onto the strap which put his flailling weight on the strap now firmly implanted in the center of his crotch. The strap which had a firm loving grip on his crotch slipped back on the overhead tube moving the center of gravity far to the rear. The wing, now pitched high, rotated rapidly to the left which swung him way out to the right. Some how after the second turn of the spin the weight of his body caused the spin to stop and head straight down with his body leading the way.

He hit the water first and the weedhopper, engine screaming, landed on top of him. A huge wall of water gushed up and a flock of geese burst into the air and went squawking off South. Those of us that were able started to run to him because we could see that his head and shoulders were underwater and the weight of the airframe and engine were holding him down. Sadly enough we only got about fifty feet across the field before we were up to our knees in mud and couldn't run anymore. The thought came to me that he was just going to have to drown because none of us could reach him. In a wild fling, he leaped up out of the water screaming "I DID IT I FLEW I DID IT I FLEW".

I sent him and his weedhopper off to other places to kill himself.

sorry about screwing up the thread...

[Hank Jarrett]

Re: Rebuilding ailerons.

Ron,
RUINED THE THREAD!!! You got to be kidding! That made me laugh myself breathless. Would have been tragic if he hadn't survived, but the mental picture of this guy fulfilling his life dream to actually FLY, regardless of the quality of the flight was worth it all. Reminds me of the pioneer aviators who felt ANY flight was a success.
Hank

Just don't let him try twice. Now it's time to show him it's not 1904 any more and how to do it right. He will carry the thrill of that flight for the rest of his life. Get him in a REAL plane so he has more time to remember his "first flight".