Glue joint resistance comparative test.
09-02-2014, 09:22 AM
#51
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Building and gluing to crash proof as suggested is a waste of time and only hinders the performance of an airplane IMO... We build to fly. The proper choice of airframe materials, adhesives, and a properly designed structure that includes proper bond lines is what is needed.
Personally I only use thin and medium CA on all my wood airframe structures including firewalls and landing gear blocks, I do use thin laminating epoxy on my sheeted foam wings and tail feathers though. There are many really great adhesives out there, most are much stronger than the materials that make up our airframes, so again bond lines are key.
Bob
Personally I only use thin and medium CA on all my wood airframe structures including firewalls and landing gear blocks, I do use thin laminating epoxy on my sheeted foam wings and tail feathers though. There are many really great adhesives out there, most are much stronger than the materials that make up our airframes, so again bond lines are key.
Bob
Oli, could you please add JB Weld to the test list.
09-02-2014, 12:10 PM
#52
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The ONLY epoxies I've seen that fall under the category of turning to chewing gum are the hobby grades of 5-minute epoxy that are marketed to us. I used them back when I was a beginning builder and noticed it in planes I had that survived long enough for it to happen and I could peel those glues out completely. That would leave an absolutely clean joint as if no glue had ever been applied except for the glue that was actually between the pieces. For example if I used it to glue on a firewall the glue would be in the joint but the fillet behind the joint came out completely.
That's when I started never using it again.
Some CA's I've used have turned to a white powder. I believe those were hit with accelerator but I don't know for certain.
in general I use carpenter's glue and 30-minute epoxy for all my building and have no worries about any of my glue joints. I don't build jets, btw, so my problems are more normal model airplane problems. I'm not dealing with the heat and stresses that you guys are.
That's when I started never using it again.
Some CA's I've used have turned to a white powder. I believe those were hit with accelerator but I don't know for certain.
in general I use carpenter's glue and 30-minute epoxy for all my building and have no worries about any of my glue joints. I don't build jets, btw, so my problems are more normal model airplane problems. I'm not dealing with the heat and stresses that you guys are.
09-02-2014, 11:44 PM
#54
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Building and gluing to crash proof as suggested is a waste of time and only hinders the performance of an airplane IMO... We build to fly. The proper choice of airframe materials, adhesives, and a properly designed structure that includes proper bond lines is what is needed.
Personally I only use thin and medium CA on all my wood airframe structures including firewalls and landing gear blocks, I do use thin laminating epoxy on my sheeted foam wings and tail feathers though. There are many really great adhesives out there, most are much stronger than the materials that make up our airframes, so again bond lines are key.
Bob
Personally I only use thin and medium CA on all my wood airframe structures including firewalls and landing gear blocks, I do use thin laminating epoxy on my sheeted foam wings and tail feathers though. There are many really great adhesives out there, most are much stronger than the materials that make up our airframes, so again bond lines are key.
Bob
On our jets it is now rare to have wood airframes. They may have some wood components like retract mounts but even these can be replaced with flex plates. Personally I have not had good results from CA. On chinese assembled airframes with built up wings they just come apart with a sharp knock failing along the glue line. I found I couldn't use CA after a very short while with the nasty side effects on my sinus. I only use it very rarely now and only when outside.
John
09-02-2014, 11:46 PM
#55
Hysol 9462 has a chemical reaction (surface tension) with the surface being glued, I did lots of tests myself on a sliced up fuselage and glued formers to it. Hysol 9462 was the best. I did peel tests, shear and others. Its not so cut and dried and the combination of materials being glued can change what I reach for. But I'd say on the vast majority of Jet builds its 9462, with some ZAP 20 (Slo Zap) and ZAP 39 (30minute)
Dw
Dw
09-03-2014, 02:43 AM
#56
Bob
On our jets it is now rare to have wood airframes. They may have some wood components like retract mounts but even these can be replaced with flex plates. Personally I have not had good results from CA. On chinese assembled airframes with built up wings they just come apart with a sharp knock failing along the glue line. I found I couldn't use CA after a very short while with the nasty side effects on my sinus. I only use it very rarely now and only when outside.
John
On our jets it is now rare to have wood airframes. They may have some wood components like retract mounts but even these can be replaced with flex plates. Personally I have not had good results from CA. On chinese assembled airframes with built up wings they just come apart with a sharp knock failing along the glue line. I found I couldn't use CA after a very short while with the nasty side effects on my sinus. I only use it very rarely now and only when outside.
John
That is why I stated a properly designed airframe that includes bond lines designed for the use of CA gluing.
Bob
09-04-2014, 07:27 AM
#58
Thread Starter
The glue joint broke at 47.5 kgs. That is a mighty 105 lbs.
That gives a shear strength of 9.20 kgs/cm2 or 131 PSI.
Note that the servo bracket is in perfect shape and ready for another test !!!
That gives a shear strength of 9.20 kgs/cm2 or 131 PSI.
Note that the servo bracket is in perfect shape and ready for another test !!!
lol
09-04-2014, 08:04 AM
#60
Oli,
that is my favorite glue. I prefer it over Aeropoxy because: sets quicker, like the color better and most importantly, I have had Aeropoxy show through the fuse while that has not happened at all with Vpoxy.
BTW, my Mig 15 was built in 98 with Aeropoxy and glue joints are as strong as new!!!! (I didnt finish the plane until 2008, but that is a different story
)
09-04-2014, 08:15 AM
#61
I have never used Hysol until now. I have glued my first formers in with 9462.
Just an observation. With the first test the mount was glued onto the timber with the grain running horizontally and the second with the grain vetical. Could this affect the outcome?
09-04-2014, 09:47 AM
#63
Thread Starter
The horizontal grain was just strong enough for the 5 min Z-poxy. The E-20HP test would have been meaningless on the same grain. The wood would have broken at about 30 kgs/ 60 lbs.
On this test with the vertical grain, the wood fibers did not separate. The glue joint sheared at the wood interface.
09-04-2014, 09:48 AM
#64
Thread Starter
09-04-2014, 09:51 AM
#65
Thread Starter
09-04-2014, 10:06 AM
#68
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Great test Oli,
Are you familiar with this adhesive (9460F)? Similar to 9462, quicker setting.
http://www.henkelna.com/product-sear...=8797872947201
Are you familiar with this adhesive (9460F)? Similar to 9462, quicker setting.
http://www.henkelna.com/product-sear...=8797872947201
Matt,
9460F used to be available, (and sold by Dreamworks), but it was my understanding it was no longer available and has not been for sometime. It had one part black, the other part white and ended up gray (looked like JB Weld when dry); and was great stuff. I wonder if you found an "old" page or if it's available again?
09-04-2014, 01:20 PM
#71
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You really should consider a safer method. Perhaps a 300lb weight on the floor if you dont want to secure an anchor to the floor... and then a ratchet with an inline scale. Just video the scale as you continue to increase pressure with the ratchet.
09-04-2014, 02:50 PM
#73
Matt,
9460F used to be available, (and sold by Dreamworks), but it was my understanding it was no longer available and has not been for sometime. It had one part black, the other part white and ended up gray (looked like JB Weld when dry); and was great stuff. I wonder if you found an "old" page or if it's available again?
9460F used to be available, (and sold by Dreamworks), but it was my understanding it was no longer available and has not been for sometime. It had one part black, the other part white and ended up gray (looked like JB Weld when dry); and was great stuff. I wonder if you found an "old" page or if it's available again?
09-05-2014, 07:51 AM
#75
Thread Starter
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