OK, I'm going to ask another fuel tank question.

I have searched all throughout the group and I still can't come up
with a decent answer. What is a good fuel tank sealant for composite
tanks, that resist the alchohol that is in todays gasoline? I can't
buy gas around here without the alchohol. There's alot of people that
do not like pro seal because it peals. What are the alternatives?
Lou

On Mar 27, 5:29 am, "Lou" wrote:
I have searched all throughout the group and I still can't come up
with a decent answer. What is a good fuel tank sealant for composite
tanks, that resist the alchohol that is in todays gasoline? I can't
buy gas around here without the alchohol. There's alot of people that
do not like pro seal because it peals. What are the alternatives?
Lou

Look into the Jeffco 9700, I believe it is rated for alcohol.

If the fuel cell is not yet manufactured, you may want to consider using
Derakane 411 vinyl ester resin. It is rated for use with fuels with an
alcohol content up to 10%. for further information visit
http://www.whitealbatross.com/misc/




"BobR" wrote in message
oups.com...
On Mar 27, 5:29 am, "Lou" wrote:
I have searched all throughout the group and I still can't come up
with a decent answer. What is a good fuel tank sealant for composite
tanks, that resist the alchohol that is in todays gasoline? I can't
buy gas around here without the alchohol. There's alot of people that
do not like pro seal because it peals. What are the alternatives?
Lou

Look into the Jeffco 9700, I believe it is rated for alcohol.

On Tue, 27 Mar 2007 14:56:51 GMT, "Doug Palmer"
wrote:

If the fuel cell is not yet manufactured, you may want to consider using
Derakane 411 vinyl ester resin. It is rated for use with fuels with an
alcohol content up to 10%. for further information visit
http://www.whitealbatross.com/misc/

My whole airplane uses Derakane, but I'd still have reservations about
the fuel system itself such as lines, pumps,O-rings, gaskets,
injectors, spider, cut off and fuel tank switching

Actually, I'd still have reservations about the fuel and resin or
using even 10% alcohol in a system unless the entire system were
designed for it. Then I have concerns about hot weather and vapor
lock.




"BobR" wrote in message
roups.com...
On Mar 27, 5:29 am, "Lou" wrote:
I have searched all throughout the group and I still can't come up
with a decent answer. What is a good fuel tank sealant for composite
tanks, that resist the alchohol that is in todays gasoline? I can't
buy gas around here without the alchohol. There's alot of people that
do not like pro seal because it peals. What are the alternatives?
Lou

Look into the Jeffco 9700, I believe it is rated for alcohol.


Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

"Lou" wrote in message
oups.com...
I have searched all throughout the group and I still can't come up
with a decent answer. What is a good fuel tank sealant for composite
tanks, that resist the alchohol that is in todays gasoline? I can't
buy gas around here without the alchohol. There's alot of people that
do not like pro seal because it peals. What are the alternatives?
Lou

After receiving many good hints to my question about one month ago I ended
up using Hylomar. This stuff is supposed to be everything-resistant, can
handle vibration and large temperature fluctuations and seals well. I've
sealed all plugs in my polyethylene tank and there not a single sign of
leakage anywhere.

Rob

"BobR" wrote in message
oups.com...
On Mar 27, 5:29 am, "Lou" wrote:
I have searched all throughout the group and I still can't come up
with a decent answer. What is a good fuel tank sealant for composite
tanks, that resist the alchohol that is in todays gasoline? I can't
buy gas around here without the alchohol. There's alot of people that
do not like pro seal because it peals. What are the alternatives?
Lou

Look into the Jeffco 9700, I believe it is rated for alcohol.


Bob,

Strictly speaking, I don't think Jeffco is rated for methyl or ethyl alcohol
in fuel. At least Jeffco Products does not explicitly say this. This is an
extremely aggressive mixture and is worst in the 10-15 vol% range. In the
testing I did for Bill Schertz, it did hold up pretty well but I only tested
for 30 days. I used the Jeffco in my tanks but would be very hesitant to
put gasohol into them. Unless Jeffco says so, you can bet you're on your
own if you use it that way. The Derakane 411 is rated up to 10% but not
over that. I would advise caution since you cannot guarantee how often you
fuel will contain 12 or 15% alcohol and methanol is worse than ethanol.

Lou, please consider using Avgas as it does not contain alcohols. If you
elect to use mogas that contains alcohol, then everything the fuel touches
that is not metal should be fluoropolymer. For hoses, they need to have an
FKM or THV tube in them. The cover can be ECO or NBR/PVC or NBR. Standard
issue nitrile (NBR) or chloroprene (Neoprene) fuel hoses will not stand up
to oxygenated gasoline. They will swell upwards of 100% by volume, weaken
to the point of collapse and stop the flow of fuel. If under sufficient
pressure, they can burst. This is also true of gaskets, seals and o-rings
that come into contact with liquid fuel.

Good luck,
Charlie Smith
KIS Cruiser 4021

Lou, please consider using Avgas as it does not contain alcohols.

Good luck,
Charlie Smith
KIS Cruiser 4021


Charlie,
A question I've never asked nor have I seen asked.
Can you use Avgas in an auto conversion engine? I'm not
against using avgas so if this can be done I would be interested
in the results.
Lou

"Lou" wrote

A question I've never asked nor have I seen asked.
Can you use Avgas in an auto conversion engine? I'm not
against using avgas so if this can be done I would be interested
in the results.

Yes, generally. If you are going to use an oxygen sensor for fuel (mixture)
control, then there is the problem of the lead fouling the sensor, and
making it nearly useless in a relatively short period of time. Some people
have put a deflector ahead of the sensor to keep from fouling them as fast,
but then they are not doing a very good job at measuring the mixture.

There are always the same problems of lead deposits, but as usual, keeping
things hot help. The largest problems with that are valve deposits, and
since auto engines are generally more tolerant of higher operating
temperatures, it is important to aggressively lean all the time, and also to
not run as rich at full power like you would an air cooled engine, but
appropriately leaned.
--
Jim in NC

Morgans wrote:
"Lou" wrote

A question I've never asked nor have I seen asked.
Can you use Avgas in an auto conversion engine? I'm not
against using avgas so if this can be done I would be interested
in the results.

Yes, generally. If you are going to use an oxygen sensor for fuel (mixture)
control, then there is the problem of the lead fouling the sensor, and
making it nearly useless in a relatively short period of time. Some people
have put a deflector ahead of the sensor to keep from fouling them as fast,
but then they are not doing a very good job at measuring the mixture.


Ed Anderson runs avgas in his rotary powered RV. The lead killing the
oxygen sensor is somewhat of a misnomer, he says. What happens is that
the sensors response rate drops dramatically as it becomes contaminated.
This does make it useless in a car, where the onboard computer uses
the sensor output to maintain a proper mixture; however, if you're just
using the sensor to tune the engine or manually lean at altitude, it's
not much of an issue. It still responds much faster than a human will.

There are always the same problems of lead deposits, but as usual, keeping
things hot help. The largest problems with that are valve deposits, and
since auto engines are generally more tolerant of higher operating
temperatures, it is important to aggressively lean all the time, and also to
not run as rich at full power like you would an air cooled engine, but
appropriately leaned.

A question I've never asked nor have I seen asked.
Can you use Avgas in an auto conversion engine? I'm not
against using avgas so if this can be done I would be interested
in the results.

Yes, generally. If you are going to use an oxygen sensor for fuel
(mixture)
control, then there is the problem of the lead fouling the sensor, and
making it nearly useless in a relatively short period of time. Some
people
have put a deflector ahead of the sensor to keep from fouling them as
fast,
but then they are not doing a very good job at measuring the mixture.


Ed Anderson runs avgas in his rotary powered RV. The lead killing the
oxygen sensor is somewhat of a misnomer, he says. What happens is that
the sensors response rate drops dramatically as it becomes contaminated.
This does make it useless in a car, where the onboard computer uses
the sensor output to maintain a proper mixture; however, if you're just
using the sensor to tune the engine or manually lean at altitude, it's
not much of an issue. It still responds much faster than a human will.

Two experiences auto mechasnics have told me the same thing, so I am
accepting this as pretty good confirmation.

Peter