21st century Volksplane?

HomeBuiltAirplanes.com

Help Support HomeBuiltAirplanes.com:

blane.c

Well-Known Member
HBA Supporter
Joined
Jun 27, 2015
Messages
3,882
Location
capital district NY
In VP-1 plans you can extend the 1/16 aircraft ply in the center wing section to cover leading edge, is that replacing the aluminum in that section or in addition to? And is it kosher to replace the entire leading edge with 1/16 aircraft ply?
 

TFF

Well-Known Member
Joined
Apr 28, 2010
Messages
12,803
Location
Memphis, TN
Besides history, T-88 has a high service temperature tolerance which is probably why it gets the nod. And while a few get picky on mixing, the vast majority just want squeeze and mix, which T-88 was invented for. They claim 160F max service and 119F temperature deflection. The stuff was made for boats about thirty years ago. It just works.
 

mcrae0104

Well-Known Member
HBA Supporter
Log Member
Joined
Oct 27, 2009
Messages
3,260
Location
BJC
It would be interesting to put some thermometer probes at various places inside the wing of a GP-4 or Falco--especially right on the inside of the skin at the spar. Is suspect it might scare a lot of folks right back to the stone-age days of resorcinol.
 

FritzW

Well-Known Member
Log Member
Joined
Jan 30, 2011
Messages
3,886
Location
Las Cruces, NM
I suppose it's a matter of perspective. I'm searching for an alternative to T-88 because of it's low temperature tolerance.

Color surface temp.jpg The OD Green fuselage on my VP-1 exceeds the max service temp for T-88 on a cool day (65f). The whole airplane exceeds the deflection temp limit on a cool day.
 

TFF

Well-Known Member
Joined
Apr 28, 2010
Messages
12,803
Location
Memphis, TN
Remember wood is a terrible conductor of heat. The surface temp can be high and the glue joint not close to its max. I believe someone took temps on their Tailwind wing and internal was not close to being scary.
 

FritzW

Well-Known Member
Log Member
Joined
Jan 30, 2011
Messages
3,886
Location
Las Cruces, NM
Wood is a good insulator but there's only a 1/16" of an inch of it between fabric that's glued to it and the T-88 glue line, and it forms a closed box (oven). If one side of a piece of 1/16th ply is uncomfortably hot, the other side isn't far behind.

Bottom line: T-88 has poor temperature tolerance.
 

Hot Wings

Grumpy Cynic
HBA Supporter
Log Member
Joined
Nov 14, 2009
Messages
6,991
Location
Rocky Mountains
Resorcinol can’t be beat for heat.
The big draw back to resorcinol seems to be getting a good fit. Is there a way to modify it's gap filling properties by mixing in something like really fine sawdust, kind of like we to with epoxy and flox/milled glass?

I'm going to use resorcinol on my laminated parts but it would be nice to be able to use it with the same fit tolerances as T-88 on the rest of the parts and just use one adhesive.
 

Victor Bravo

Well-Known Member
Joined
Jul 30, 2014
Messages
7,228
Location
KWHP, Los Angeles CA, USA
Does anyone here have knowledge and experience with the Hughes FPL-16 and other "resorcinol replacement options" that were developed over the years?

Also, I know for a fact that there are now several higher temperature epoxies used in composite construction. (I personally saw what was clearly some kind of a carbon composite jet exhaust duct on the later jet powered Predator drone a couple of years ago at one of their facilities)

Can one of these "laminating" epoxies be thickened slightly to create a structural gap-filling adhesive with higher temperature tolerances?

 

BJC

Well-Known Member
HBA Supporter
Joined
Oct 7, 2013
Messages
11,056
Location
97FL, Florida, USA
Is anyone aware of a documented T88 joint that failed due to temperature?

There are lots of wooden wings on airshow nd competition airplanes that sit in the hot sun, then get heavily loaded in flight. Yes, I’ve heard the claims that rapid cooling occurs on takeoff.


BJC
 

blane.c

Well-Known Member
HBA Supporter
Joined
Jun 27, 2015
Messages
3,882
Location
capital district NY
I don't know anything about T-88 failures. I know I am supposed to have weather and boil proof plywood, so why wouldn't I use weather and boil proof glue to stick the lumber to it?
 
2
Top