Epoxy Choice


Martin Skiby
 

I am getting ready to order my first round of Epoxy. I have decided on the EX poxy system but have a question about the hardner. 83 or 84?

Looking for guidance.

I have a bunch of old Aero Poxy and pump already, but it is 10 years old and may just use it for fill. I am getting new pump and going with the EZ poxy based on a recomendation by a trusted source.


Fisher Paul A. <fisherpaula@...>
 

Weak data point -
Last time I used EZ Poxy, I ordered a 1-1/2 Quart kit from Aircraft Spruce (P/N 01-08050). It mixed and acted exactly like the Safe-T-Poxy the plane was originally built with. That kit from AS&S comes with the 83 hardener, so my gut reaction is to use 83.

Perhaps someone with more expertise (Charlie?!?) can give you a more technical answer, but as weak as it is, it's the only data point I have!

Good Luck!

Paul A. Fisher
Q-200, N17PF ~1400 hours over 20+ years


From: Q-LIST@... [mailto:Q-LIST@...] On Behalf Of Martin
Sent: Wednesday, January 12, 2011 13:21
To: Q-LIST@...
Subject: [Q-LIST] Epoxy Choice



I am getting ready to order my first round of Epoxy. I have decided on the EX poxy system but have a question about the hardner. 83 or 84?

Looking for guidance.

I have a bunch of old Aero Poxy and pump already, but it is 10 years old and may just use it for fill. I am getting new pump and going with the EZ poxy based on a recomendation by a trusted source.


One Sky Dog
 

Martin, Paul,

According to my inside resin formulator from the EZ Poxy folks. It is the
same formulation as Safe-T-Poxy. Hexcel (deep pockets)dumped it as soon as
someone linked DMA in the cure agent to cancer. The formulator said you
have to be cooking the cure agent to be exposed to a hazardous level. Good
shop ventilation practices should preclude using any chemicals including
epoxies. Early epoxies were strong sensitizers and people became allergic to
them. Safe-T-Poxy is not a strong sensitizer and it takes more exposure to
become allergic to it. The DMA is another issue and if concerned a respirator
with an organic vapor cartridge in addition to shop ventilation would be a
good practice.

Wear your nitrile gloves if you get it on you wash with soap and water
then Orange hand cleaner with pumice. Do not wash in solvents. Do not eat
epoxy use a shop coat or shop clothes and change when going to work or stoping
work on the project.

I do not see a reason to use 84 hardener on the Q. I think the 84
hardener is more suited to a vacuum infusion process. It takes 3 times as long to
cure so you are going to slow things way down but the working life is the
same. Only benefit is easier wet out but 83 should wet out fine at room temp.

Do not work in a cold shop you will add many pounds of epoxy to your plane
from the increased viscosity.

Regards Technobabble,

Charlie Johnson
Ogden, Utah

In a message dated 1/12/2011 12:50:58 P.M. Mountain Standard Time,
fisherpaula@... writes:

Weak data point -
Last time I used EZ Poxy, I ordered a 1-1/2 Quart kit from Aircraft Spruce
(P/N 01-08050). It mixed and acted exactly like the Safe-T-Poxy the plane
was originally built with. That kit from AS&S comes with the 83 hardener,
so my gut reaction is to use 83.

Perhaps someone with more expertise (Charlie?!?) can give you a more
technical answer, but as weak as it is, it's the only data point I have!

Good Luck!

Paul A. Fisher
Q-200, N17PF ~1400 hours over 20+ years


Martin Skiby
 

Thanks Charlie, All good practices. We built the original Vari Eze with Safty Poxy as well as the first Q200. My father in law was the expert at the epoxy work and mixing, but he passed away a year ago. With the Ez Poxy I was aware that it was the same formula, I just wanted to get an opinion of the hardner to use. I think the 24 hour cure is a better idea also. The aeropoxy that I have been using takes three days to cure and it is a pain. I start wondering every time if my pump failed to mix it correctly! But finally it sets nice.

Thanks for the opinions. I will get my order ready. We are off and working.

--- In Q-LIST@..., oneskydog@... wrote:

Martin, Paul,

According to my inside resin formulator from the EZ Poxy folks. It is the
same formulation as Safe-T-Poxy. Hexcel (deep pockets)dumped it as soon as
someone linked DMA in the cure agent to cancer. The formulator said you
have to be cooking the cure agent to be exposed to a hazardous level. Good
shop ventilation practices should preclude using any chemicals including
epoxies. Early epoxies were strong sensitizers and people became allergic to
them. Safe-T-Poxy is not a strong sensitizer and it takes more exposure to
become allergic to it. The DMA is another issue and if concerned a respirator
with an organic vapor cartridge in addition to shop ventilation would be a
good practice.

Wear your nitrile gloves if you get it on you wash with soap and water
then Orange hand cleaner with pumice. Do not wash in solvents. Do not eat
epoxy use a shop coat or shop clothes and change when going to work or stoping
work on the project.

I do not see a reason to use 84 hardener on the Q. I think the 84
hardener is more suited to a vacuum infusion process. It takes 3 times as long to
cure so you are going to slow things way down but the working life is the
same. Only benefit is easier wet out but 83 should wet out fine at room temp.

Do not work in a cold shop you will add many pounds of epoxy to your plane
from the increased viscosity.

Regards Technobabble,

Charlie Johnson
Ogden, Utah


In a message dated 1/12/2011 12:50:58 P.M. Mountain Standard Time,
fisherpaula@... writes:

Weak data point -
Last time I used EZ Poxy, I ordered a 1-1/2 Quart kit from Aircraft Spruce
(P/N 01-08050). It mixed and acted exactly like the Safe-T-Poxy the plane
was originally built with. That kit from AS&S comes with the 83 hardener,
so my gut reaction is to use 83.

Perhaps someone with more expertise (Charlie?!?) can give you a more
technical answer, but as weak as it is, it's the only data point I have!

Good Luck!

Paul A. Fisher
Q-200, N17PF ~1400 hours over 20+ years





[Non-text portions of this message have been removed]


Guy
 

I would avoid using Aeropoxy for filling unless you really like sanding and repairing sand-throughs. Aeropoxy is a structural lamination system and the resin is pretty hard to sand. You will save more time using an epoxy like AlphaPoxy or even West System since they are easier to sand than EZ-Poxy, AeroPoxy, MGS, Proset...etal. Using it for flox corners or flox bonds would be OK but you might as well use the laminating system that you chose to begin with. I'm planning to use Aeropoxy light for filling. I'll let you know how it goes when it warms up around here!

Guy Bowen
Dragonfly MKII

--- In Q-LIST@..., "Martin" <mskiby@...> wrote:

I am getting ready to order my first round of Epoxy. I have decided on the EX poxy system but have a question about the hardner. 83 or 84?

Looking for guidance.

I have a bunch of old Aero Poxy and pump already, but it is 10 years old and may just use it for fill. I am getting new pump and going with the EZ poxy based on a recomendation by a trusted source.


dkeats <dkeats@...>
 

Guy----- Years ago when I was building I used the West System for filler. What I would do was to mix up some epoxi, add in 20% volume methol hydrate, mix, and then add in the micro balloons. Mix it up and use it as a filler. Spreads real easy. The methol hydrate will evaporate and the epoxi will harden. Way easier to sand than pure epoxi. NOT for structure of anykind. The reason I used methol hydrate is I found it was one of the few things that would actually mix with epoxi and it will not eat the blue foam. Works for me------------ Canada Chris