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bernard.wilder2(at)gmail.
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 Posted: Mon Sep 30, 2013 5:22 pm Post subject: Fwd: Fuel Tanks |
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---------- Forwarded message ----------
From: Bernard Wilder <bernard.wilder2(at)gmail.com>
Date: Mon, Sep 30, 2013 at 9:19 PM
Subject: Re: Fuel Tanks
To: Ray Thurman <raythur(at)gvtc.com>
Ray,
Fuel cells were coated by Aero Designs around 1995. I was told they
used something called Kreem ? ? ? ?
The white you see is where the coating has completely come off. There
was no residue inside the cell so the coating appears to have disolved
not chipped off..
The laminating poxy is whatever Aero Designs used to make the fast
build wing. Do you know what that was ? ? ?
At least one other builder I know of has had the coating inside the
fuel cell partially disappear.
I also heard from a chap in Germany whose XP fuel cells had areas
where the micro in the joint had not been covered by cloth lay-up and
had turned mushy. It had also turned white. The bond between the
fuel cell and the spar top was in his words "non existing" out
approximately 300 mm from the tank close out. Disturbing to say the
least. His wing had been built by Aero Designs.
I am going to copy this to the net so they can see all comments.
Thanks for your input.
Bernie Wilder
On Mon, Sep 30, 2013 at 4:28 PM, Ray Thurman <raythur(at)gvtc.com> wrote:
| Quote: | First of all I'm no expert...
It looks like the tanks were originally coated with Jeffco 9700 (now called
Rhino 9700) based on the grey coating near the filler neck. What's all that
white stuff??? It looks like ethanol reacted with your laminating epoxy
(Epolite 2410?), or fuel has deposited a white substance, I don't know and
can't tell from the pictures. I'd pick at it to see what it is or seems
like, is it brittle or gummy or what. I'd also find a way to verify the
integrity of the wet layups, maybe I'd pick at it to see if any areas are
loose or pull up easily. Somehow you have to verify they are secure and
strong. Once you're satisfied the glass layups are intact then it's a matter
of surface prep and recoating. I'd go with the Rhino 9700 since it is known
to resist the attacks of ethanol. I'm still puzzled why the original tank
coating has failed.
Jeffco (Rhino) is a Novolac based epoxy made for resistance to a wide
variety of chemicals. Other floor coating epoxies probably are not.
I really want to know what that white stuff is and what happened to the
original tank coating. Were these built at Aero-Designs?
Ray
On 9/30/2013 11:15 AM, Bernard Wilder wrote:
>
> Attached are pics of the inside of my fuel cell.
>
> Kit No. 390
>
> Lay-ups within seem not to be damaged. I assume epoxy was used
> throughout.
>
> Jeffco is an epoxy. Let me ask the dumb question: Does epoxy need to
> be coated with another epoxy ? ? ?
>
> Jeffco is a two part epoxy. Valspar garage floor coating is a two
> part expoy. Is there a structural or chemical difference ? ? ?
>
> I am working with a bladder manufacturer to see if a bladder is
> aviable solution. There are some issues.
>
> Comments ? ? ? ? ?
>
> Bernie Wilder
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gregsmi
Joined: 01 Jan 2011
Posts: 268
Location: Topeka, KS
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| Posted: Mon Sep 30, 2013 7:16 pm Post subject: Fwd: Fuel Tanks |
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|
Bob and all. In testing ethanol affects on different epoxies, we found that everything we tested, both laminating and structural adhesive, would dissolve if it was a room temperature cured bond. We also found that oven cured composite was not affected. The composite formed parts use a prepreg fiberglass that was formed in the mold then rolled into an oven for 4 - 8 hours of cure.
We tested PRC sealed surfaces and found that PRC did resist ethanol. We did not test Kreem.
These test were conducted with samples being exposed over a years time.
The conclusions are not too good. The tanks are attached to the wing during the build process, using room temperature cured structural adhesive. If the sealing agent fails, the epoxy joints are exposed to ethanol.
It would seem the best approach is to first inspect the sealant in the tank and the bonding surface. Seal the tank with PRC or other products that will resist ethanol. Then, do not use ethanol laced fuel.
Another option, after inspection and sealing is to use a fuel bladder insert.
Remember when you built your aircraft, you attached the fuel tanks to the spar with structural adhesive. If you bought a fast build wing, that just means someone else did the same thing. Back then, ethanol was not being put in auto fuel.
I hope others will chime in here. Maybe there are other options. I am just relating to you the test I did with samples placed in a sealed jar of ethanol auto fuel.
Greg
In a message dated 9/30/2013 8:23:08 P.M. Central Daylight Time, bernard.wilder2(at)gmail.com writes:
| Quote: | --> Pulsar-List message posted by: Bernard Wilder <bernard.wilder2(at)gmail.com>
---------- Forwarded message ----------
From: Bernard Wilder <bernard.wilder2(at)gmail.com>
Date: Mon, Sep 30, 2013 at 9:19 PM
Subject: Re: Fuel Tanks
To: Ray Thurman <raythur(at)gvtc.com>
Ray,
Fuel cells were coated by Aero Designs around 1995. I was told they
used something called Kreem ? ? ? ?
The white you see is where the coating has completely come off. There
was no residue inside the cell so the coating appears to have disolved
not chipped off..
The laminating poxy is whatever Aero Designs used to make the fast
build wing. Do you know what that was ? ? ?
At least one other builder I know of has had the coating inside the
fuel cell partially disappear.
I also heard from a chap in Germany whose XP fuel cells had areas
where the micro in the joint had not been covered by cloth lay-up and
had turned mushy. It had also turned white. The bond between the
fuel cell and the spar top was in his words "non existing" out
approximately 300 mm from the tank close out. Disturbing to say the
least. His wing had been built by Aero Designs.
I am going to copy this to the net so they can see all comments.
Thanks for your input.
Bernie Wilder
On Mon, Sep 30, 2013 at 4:28 PM, Ray Thurman <raythur(at)gvtc.com> wrote:
| Quote: | First of all I'm no expert...
It looks like the tanks were originally coated with Jeffco 9700 (now called
Rhino 9700) based on the grey coating near the filler neck. What's all that
white stuff??? It looks like ethanol reacted with your laminating epoxy
(Epolite 2410?), or fuel has deposited a white substance, I don't know and
can't tell from the pictures. I'd pick at it to see what it is or seems
like, is it brittle or gummy or what. I'd also find a way to verify the
integrity of the wet layups, maybe I'd pick at it to see if any areas are
loose or pull up easily. Somehow you have to verify they are secure and
strong. Once you're satisfied the glass layups are intact then it's a matter
of surface prep and recoating. I'd go with the Rhino 9700 since it is known
to resist the attacks of ethanol. I'm still puzzled why the original tank
coating has failed.
Jeffco (Rhino) is a Novolac based epoxy made for resistance to a wide
variety of chemicals. Other floor coating epoxies probably are not.
I really want to know what that white stuff is and what happened to the
original tank coating. Were these built at Aero-Designs?
Ray
On 9/30/2013 11:15 AM, Bernard Wilder wrote:
>
> Attached are pics of the inside of my fuel cell.
>
> Kit No. 390
>
> Lay-ups within seem not to be damaged. I assume epoxy was used
> throughout.
>
> Jeffco is an epoxy. Let me ask the dumb question: Does epoxy need to
> be coated with another epoxy ? ? ?
>
> Jeffco is a two part epoxy. Valspar garage floor coating is a two
> part expoy. Is there a structural or chemical difference ? ? ?
>
> I am working with a bladder manufacturer to see if a bladder is
> aviable solution. There are some issues.
>
> Comments ? ? ? ? ?
>
> Bernie the ies ay - MATRONICS WEB FORUMS - List Contribution Web Site p;
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cking(at)lifesize.com
Guest
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| Posted: Tue Oct 01, 2013 11:13 am Post subject: Fwd: Fuel Tanks |
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Hmmm. Seeing that the last time I flew my plane was year ago … ugh. I can tell you that ethanol has never touched the inside of my tanks. I have never fixed my leak at the endplate that was the reason that I took the plane out of service to begin with. Mine were the composite skins, but I built them not Aero Designs. Curious to finally take that endplate off and take a peek inside!
ck
On Sep 30, 2013, at 10:14 PM, gregsmi(at)aol.com (gregsmi(at)aol.com) wrote:
[quote] Bob and all. In testing ethanol affects on different epoxies, we found that everything we tested, both laminating and structural adhesive, would dissolve if it was a room temperature cured bond. We also found that oven cured composite was not affected. The composite formed parts use a prepreg fiberglass that was formed in the mold then rolled into an oven for 4 - 8 hours of cure.
We tested PRC sealed surfaces and found that PRC did resist ethanol. We did not test Kreem.
These test were conducted with samples being exposed over a years time.
The conclusions are not too good. The tanks are attached to the wing during the build process, using room temperature cured structural adhesive. If the sealing agent fails, the epoxy joints are exposed to ethanol.
It would seem the best approach is to first inspect the sealant in the tank and the bonding surface. Seal the tank with PRC or other products that will resist ethanol. Then, do not use ethanol laced fuel.
Another option, after inspection and sealing is to use a fuel bladder insert.
Remember when you built your aircraft, you attached the fuel tanks to the spar with structural adhesive. If you bought a fast build wing, that just means someone else did the same thing. Back then, ethanol was not being put in auto fuel.
I hope others will chime in here. Maybe there are other options. I am just relating to you the test I did with samples placed in a sealed jar of ethanol auto fuel.
Greg
In a message dated 9/30/2013 8:23:08 P.M. Central Daylight Time, bernard.wilder2(at)gmail.com (bernard.wilder2(at)gmail.com) writes:
| Quote: | --> Pulsar-List message posted by: Bernard Wilder <bernard.wilder2(at)gmail.com (bernard.wilder2(at)gmail.com)>
---------- Forwarded message ----------
From: Bernard Wilder <bernard.wilder2(at)gmail.com (bernard.wilder2(at)gmail.com)>
Date: Mon, Sep 30, 2013 at 9:19 PM
Subject: Re: Fuel Tanks
To: Ray Thurman <raythur(at)gvtc.com (raythur(at)gvtc.com)>
Ray,
Fuel cells were coated by Aero Designs around 1995. I was told they
used something called Kreem ? ? ? ?
The white you see is where the coating has completely come off. There
was no residue inside the cell so the coating appears to have disolved
not chipped off..
The laminating poxy is whatever Aero Designs used to make the fast
build wing. Do you know what that was ? ? ?
At least one other builder I know of has had the coating inside the
fuel cell partially disappear.
I also heard from a chap in Germany whose XP fuel cells had areas
where the micro in the joint had not been covered by cloth lay-up and
had turned mushy. It had also turned white. The bond between the
fuel cell and the spar top was in his words "non existing" out
approximately 300 mm from the tank close out. Disturbing to say the
least. His wing had been built by Aero Designs.
I am going to copy this to the net so they can see all comments.
Thanks for your input.
Bernie Wilder
On Mon, Sep 30, 2013 at 4:28 PM, Ray Thurman <raythur(at)gvtc.com (raythur(at)gvtc.com)> wrote:
| Quote: | First of all I'm no expert...
It looks like the tanks were originally coated with Jeffco 9700 (now called
Rhino 9700) based on the grey coating near the filler neck. What's all that
white stuff??? It looks like ethanol reacted with your laminating epoxy
(Epolite 2410?), or fuel has deposited a white substance, I don't know and
can't tell from the pictures. I'd pick at it to see what it is or seems
like, is it brittle or gummy or what. I'd also find a way to verify the
integrity of the wet layups, maybe I'd pick at it to see if any areas are
loose or pull up easily. Somehow you have to verify they are secure and
strong. Once you're satisfied the glass layups are intact then it's a matter
of surface prep and recoating. I'd go with the Rhino 9700 since it is known
to resist the attacks of ethanol. I'm still puzzled why the original tank
coating has failed.
Jeffco (Rhino) is a Novolac based epoxy made for resistance to a wide
variety of chemicals. Other floor coating epoxies probably are not.
I really want to know what that white stuff is and what happened to the
original tank coating. Were these built at Aero-Designs?
Ray
On 9/30/2013 11:15 AM, Bernard Wilder wrote:
>
> Attached are pics of the inside of my fuel cell.
>
> Kit No. 390
>
> Lay-ups within seem not to be damaged. I assume epoxy was used
> throughout.
>
> Jeffco is an epoxy. Let me ask the dumb question: Does epoxy need to
> be coated with another epoxy ? ? ?
>
> Jeffco is a two part epoxy. Valspar garage floor coating is a two
> part expoy. Is there a structural or chemical difference ? ? ?
>
> I am working with a bladder manufacturer to see if a bladder is
> aviable solution. There are some issues.
>
> Comments ? ? ? ? ?
>
> Bernie the ies ay - MATRONICS WEB FORUMS - List Contribution Web Site p;
|
|
[b]
| | - The Matronics Pulsar-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Pulsar-List |
|
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| Back to top |
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