West Systems 105 Epoxy

Anyone know if West Systems 105 epoxy with 205/206 hardner is considered to be a "structural" epoxy? I'm putting one of Laird Owen's composite panels into my RV6A and the instructions call for a structural adhesive and mention PTM&W ES6279 and Hysol EA-9430 by name. It seems as though those are just high quality epoxies as far as I can tell, though - and I've already got a fair amount of the west systems stuff on-hand.

No it's not considered structural. It's probably plenty good enough for the installation. I'll be by WHP tonight, if Laird is there, I'll ask him.

West epoxy

There are lots of boats built with West, and at least 3 homebuilts on our field glued with it. So far they have not drpped out of the sky. What can be said.
West has an excellent publication on the various applications. Can be had from their web site. Used West on my RV10/
TT
RV10

High temperature limits

I believe the weak part of the West system is the high temperature specifications. All epoxies get weaker with temperature.

In general, the parts of a boat are sort of close to the water temperature... while a painted aircraft structure could get into the 160 F range.... that's why sailplanes are white....

West epoxies have a temperature of 120 F to 130 F where the properties degrade. That's less than the ramp temperature in AZ...

http://westsystem.com/frames/tier2/productinfo/typicalphysicalproperties.htm

The Hysol is still specified (at reduced strength) at 180 F.

West should be OK for fairings and filling stuff, but I'm not sure I would want an entire cowling made from it... and defnitely not a wing spar...

gil A

PS ...a DER let me use EPK 1C or EPK 6C for a structural repair on a friends Cheetah. These Hysol ones are easily obtained from Grainger and come in two small toothpaste type tubes... great if you only need a small quantitiy.

Thanks for all the responses - I hadn't thought about the marine applications (which, oddly enough, is why I had the stuff nor about the high temperature items. Given the relatively small amount, I'll go ahead and order up some of the "good stuff" tommorow.

Thanks!
-Brad

Hysol also at Aircraft Spruce

Aircraft Spruce also sells Hysol EPL0151 and EPK1C in tubes and 9430 in a 2 LB can.

Good hunting,
Mike

Post Cure

I wonder why they did not list glass transiiton temperatures for post cured samples. Room temperature cure data is a bit on the low side.
I use EX-Poxy quite a bit. Room temperature cure glass transition temp is in the 140-150's. Post curing takes that to nearly 200 deg F




E-Z POXY TECHNICAL DATA
E-Z POXY RESIN SYSTEMS FROM COMPOSITE POLYMER DESIGN
E-Z 10 Epoxy Resin E-Z 84 Aromatic Amine Hardener
E-Z 83 Aromatic Amine Hardener E-Z 87 Aromatic Amin Hardener

E-Z 10 Resin (Viscosity 1500 cps @ 77F) with:
Hardener EZ 83 EZ 84 EZ 87
Mixed Properties:
Mixed Viscosity cps @ 77F* 1300 800 1500
Viscosity Hardener cps @ 77F* 410 140 830
Pot Life @ 77F 2 hours 2 hours 5 hours
Tack Free @ 77F 4 hours 8 hours 8 hours
Cure Time @ 77F 24 hours 3 days 3 days
Mix Ratio by Volume 100/47 100/47 100/47
Mix Ratio by Weight 100/44 100/44 100/44
Physical Properties Tg (F):
R/T 151 151 142
P/C* 196 196 196
Elongation % 3.5 3.5 3.9
Specific Gravity 1.14 1.13 1.14
Linear Shrinkage @ 23C (4 days %) .10 .10 .10
Tensile Strength PSI:
R/T 8,200 8,100 8,400
P/C 10,000 10,000 10,000
Tensile Modulus (PSI x 10 -5) 4.8 4.2 4.0
* Viscosity may vary +/- 10%
* Post Cure for 2 hrs. @ 150F

Look at the One Design.............. +10/-10g all glued together with West Epoxy in the spars, skin, covering etc !

It is structural, it is superb to work with and I have used it for years.

I've been using it today to do repairs to both a 1944 Tiger Moth and my RV7. Mr De Havilland will be spinning in his grave