Topics

EZ Poxy Post Cure Timing Questions


alpineracing
 

Good Morning Everyone,

I just did a strengthening layup on my Velocity XLRG near the top of the doors on the ceiling (when the doors are hung on the Velocity’s, everything fits perfectly, THEN, you hang your engine and you find your doors are EXTREMELY difficult to close and are misaligned).

This is a stiffening modification to strengthen the fuselage and keep them from twisting.  Airplane is currently on the wing jacks which alleviates the engine weight twist so when up on jacks, the doors align and close much better.  This modification is done while on the jacks.  Basically a 5-Ply BID Carbon Fiber layup on top of divincel foam - one setup for each door area.  This is now done and came out great.

Question to the group (I also reached out to Gary Hunter but not sure I had his email correct) is at what temperature should I “Post cure” the interior cabin?  My fear is that even though this worked perfectly, some day I will be parked on the ramp somewhere on a hot day and the temps similar to a car interior could heat everything up and that “twist/flex” could be allowed to set back in (however now “post cured” to a much higher temperature).

Questions:

1. What temperature should I heat interior to and for how long?  (I was told 130 to 140 degrees Fahrenheit should do the trick)?
2. Best method?  (I was told a hair dryer with a way to monitor temperature may be the way to go) I cannot use a heat gun as I need to keep the doors closed and in place.
3. How long to wait before putting plane back on its gear after a post cure?  Do I have to wait another day or two to “re-cure”?

Thanks and hope everyone is doing well,

Gary Ernest
Velocity XLRG
ARB, MI
email: alpineracing@...
**********************************



Terry Schubert
 

 Hi Gary,
 
When the topic guru isn't available always look at CSA back issues.
 
In this case, see Gary Hunter's article attached from 2013.
 
For the future, I'm putting together all 34 years of CSA in digital format with an index.  Stay tuned for the back issue project update.  COBA.clubexpress.com
 
 
 
Terry Schubert
Central States Association Newsletter Editor Emeritus


---------- Original Message ----------
From: "alpineracing" <alpineracing@...>
To: canard-aviators@canardzone.groups.io
Subject: [c-a] EZ Poxy Post Cure Timing Questions
Date: Fri, 29 May 2020 09:42:59 -0400

Good Morning Everyone,

 
I just did a strengthening layup on my Velocity XLRG near the top of the doors on the ceiling (when the doors are hung on the Velocity’s, everything fits perfectly, THEN, you hang your engine and you find your doors are EXTREMELY difficult to close and are misaligned).

This is a stiffening modification to strengthen the fuselage and keep them from twisting.  Airplane is currently on the wing jacks which alleviates the engine weight twist so when up on jacks, the doors align and close much better.  This modification is done while on the jacks.  Basically a 5-Ply BID Carbon Fiber layup on top of divincel foam - one setup for each door area.  This is now done and came out great.
 
Question to the group (I also reached out to Gary Hunter but not sure I had his email correct) is at what temperature should I “Post cure” the interior cabin?  My fear is that even though this worked perfectly, some day I will be parked on the ramp somewhere on a hot day and the temps similar to a car interior could heat everything up and that “twist/flex” could be allowed to set back in (however now “post cured” to a much higher temperature).
 
Questions:
 
1. What temperature should I heat interior to and for how long?  (I was told 130 to 140 degrees Fahrenheit should do the trick)?
2. Best method?  (I was told a hair dryer with a way to monitor temperature may be the way to go) I cannot use a heat gun as I need to keep the doors closed and in place.
3. How long to wait before putting plane back on its gear after a post cure?  Do I have to wait another day or two to “re-cure”?
 
Thanks and hope everyone is doing well,
 
Gary Ernest
Velocity XLRG
ARB, MI
email: alpineracing@...

**********************************

 

 


DON JONES
 

I would suggest checking online for the manufacturing  information docs. Or, contact the manufacturer. The 130 to 140 degree range should be safe for the core material, but different blends may require different lengths of time for an adequate post cure.

Don Jones
Berkut FG

On Friday, May 29, 2020, 10:18:04 AM EDT, Terry Schubert <jschuber@...> wrote:


 Hi Gary,
 
When the topic guru isn't available always look at CSA back issues.
 
In this case, see Gary Hunter's article attached from 2013.
 
For the future, I'm putting together all 34 years of CSA in digital format with an index.  Stay tuned for the back issue project update.  COBA.clubexpress.com
 
 
 
Terry Schubert
Central States Association Newsletter Editor Emeritus

---------- Original Message ----------
From: "alpineracing" <alpineracing@...>
To: canard-aviators@canardzone.groups.io
Subject: [c-a] EZ Poxy Post Cure Timing Questions
Date: Fri, 29 May 2020 09:42:59 -0400

Good Morning Everyone,

 
I just did a strengthening layup on my Velocity XLRG near the top of the doors on the ceiling (when the doors are hung on the Velocity’s, everything fits perfectly, THEN, you hang your engine and you find your doors are EXTREMELY difficult to close and are misaligned).

This is a stiffening modification to strengthen the fuselage and keep them from twisting.  Airplane is currently on the wing jacks which alleviates the engine weight twist so when up on jacks, the doors align and close much better.  This modification is done while on the jacks.  Basically a 5-Ply BID Carbon Fiber layup on top of divincel foam - one setup for each door area.  This is now done and came out great.
 
Question to the group (I also reached out to Gary Hunter but not sure I had his email correct) is at what temperature should I “Post cure” the interior cabin?  My fear is that even though this worked perfectly, some day I will be parked on the ramp somewhere on a hot day and the temps similar to a car interior could heat everything up and that “twist/flex” could be allowed to set back in (however now “post cured” to a much higher temperature).
 
Questions:
 
1. What temperature should I heat interior to and for how long?  (I was told 130 to 140 degrees Fahrenheit should do the trick)?
2. Best method?  (I was told a hair dryer with a way to monitor temperature may be the way to go) I cannot use a heat gun as I need to keep the doors closed and in place.
3. How long to wait before putting plane back on its gear after a post cure?  Do I have to wait another day or two to “re-cure”?
 
Thanks and hope everyone is doing well,
 
Gary Ernest
Velocity XLRG
ARB, MI
email: alpineracing@...

**********************************

 

 


bowengor46er
 

The max amount of post cure needed or even possible is determined by the formulation’s chemistry. Tg is the “glass transition” temp of the resin/hardener mix. This is a fixed property of the formula. Above about 165F, EZpoxy will always transition from a glass like matrix to a rubbery matrix. Post curing any RT laminate is a function of time at temp. Generally, the best way to postcure this particular problem area would be to use a heating pad and a thermometer. Max results would probably be 150F for 2 hrs. But this will depend on the core material.


Terry Schubert
 

Hi Gordon,
 
Thanks for the input.
 
In the future you might include your being the Sate-T-Poxy/EZpoxy formuator.  All the geezers know who you are but the generation 2 builders probably don't. 


Terry Schubert
Central States Association Newsletter Editor Emeritus


---------- Original Message ----------
From: "bowengor46er" <gordon.bowen.training@...>
To: canard-aviators@canardzone.groups.io
Subject: Re: [c-a] EZ Poxy Post Cure Timing Questions
Date: Sat, 30 May 2020 07:39:53 -0800

The max amount of post cure needed or even possible is determined by the formulation’s chemistry.  Tg is the “glass transition” temp of the resin/hardener mix.  This is a fixed property of the formula.  Above about 165F, EZpoxy will always transition from a glass like matrix to a rubbery matrix. Post curing any RT laminate is a function of time at temp. Generally, the best way to postcure this particular problem area would be to use a heating pad and a thermometer.  Max results would probably be 150F for 2 hrs. But this will depend on the core material.


Rick Caldwell
 

Terry,

     Since we are on the subject of post cure.  How about the parts that are several years old, would they benefit from the process also?

Rick C

 

From: canard-aviators@canardzone.groups.io [mailto:canard-aviators@canardzone.groups.io] On Behalf Of Terry Schubert
Sent: Saturday, May 30, 2020 10:05 AM
To: canard-aviators@canardzone.groups.io
Subject: Re: [c-a] EZ Poxy Post Cure Timing Questions

 

Hi Gordon,

 

Thanks for the input.

 

In the future you might include your being the Sate-T-Poxy/EZpoxy formuator.  All the geezers know who you are but the generation 2 builders probably don't. 


Terry Schubert
Central States Association Newsletter Editor Emeritus

---------- Original Message ----------
From: "bowengor46er" <gordon.bowen.training@...>
To: canard-aviators@canardzone.groups.io
Subject: Re: [c-a] EZ Poxy Post Cure Timing Questions
Date: Sat, 30 May 2020 07:39:53 -0800

The max amount of post cure needed or even possible is determined by the formulation’s chemistry.  Tg is the “glass transition” temp of the resin/hardener mix.  This is a fixed property of the formula.  Above about 165F, EZpoxy will always transition from a glass like matrix to a rubbery matrix. Post curing any RT laminate is a function of time at temp. Generally, the best way to postcure this particular problem area would be to use a heating pad and a thermometer.  Max results would probably be 150F for 2 hrs. But this will depend on the core material.


Dale Martin
 

Hey Gary,

Gordon (who posted earlier) is also an expert in the area of epoxy and would agree with him.   Further, I think he might  also agree that when post curing with   foam cores become involved you need to be aware or “creep” as the foam stresses change.   When doing  post curing I would advise you do it inside the original mold and if it isn’t feasible bond plywood on edge to the part with Bondo to insure the parts are not altered by the heat.   Thinking of the Velocity gear doors you would need the use multiple pieces of plywood attached one another and the door to maintain its shape and do include right angle intersections to avoid twist.

Dale




On Fri, May 29, 2020 at 6:43 AM alpineracing <alpineracing@...> wrote:
Good Morning Everyone,

I just did a strengthening layup on my Velocity XLRG near the top of the doors on the ceiling (when the doors are hung on the Velocity’s, everything fits perfectly, THEN, you hang your engine and you find your doors are EXTREMELY difficult to close and are misaligned).

This is a stiffening modification to strengthen the fuselage and keep them from twisting.  Airplane is currently on the wing jacks which alleviates the engine weight twist so when up on jacks, the doors align and close much better.  This modification is done while on the jacks.  Basically a 5-Ply BID Carbon Fiber layup on top of divincel foam - one setup for each door area.  This is now done and came out great.

Question to the group (I also reached out to Gary Hunter but not sure I had his email correct) is at what temperature should I “Post cure” the interior cabin?  My fear is that even though this worked perfectly, some day I will be parked on the ramp somewhere on a hot day and the temps similar to a car interior could heat everything up and that “twist/flex” could be allowed to set back in (however now “post cured” to a much higher temperature).

Questions:

1. What temperature should I heat interior to and for how long?  (I was told 130 to 140 degrees Fahrenheit should do the trick)?
2. Best method?  (I was told a hair dryer with a way to monitor temperature may be the way to go) I cannot use a heat gun as I need to keep the doors closed and in place.
3. How long to wait before putting plane back on its gear after a post cure?  Do I have to wait another day or two to “re-cure”?

Thanks and hope everyone is doing well,

Gary Ernest
Velocity XLRG
ARB, MI
email: alpineracing@...
**********************************


--
Dale
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