Pro Seal
Bruce A. Frank
significantly extend the shelf life? Will freezing the unmixed polymer,
for extended storage, cause any problems? It would have been nice if
Aircraft Spruce had included the Material Safety Data Sheet.
--
Bruce A. Frank, Editor "Ford 3.8/4.2L Engine and V-6 STOL
BAFRANK(at)worldnet.att.net Homebuilt Aircraft Newsletter"
| Publishing interesting material|
| on all aspects of alternative |
| engines and homebuilt aircraft.|
*------------------------------**----*
\(-o-)/ AIRCRAFT PROJECTS CO.
\___/ Manufacturing parts & pieces
/ \ for homebuilt aircraft,
0 0 TIG welding
While trying to find the time to finish mine.
Frank van der Hulst
> Does anyone know what the pot life of mixed Pro Seal?
Quite short -- a couple of hours.
> Will refrigeration
> significantly extend the shelf life?
I think so.
> Will freezing the unmixed polymer,
> for extended storage, cause any problems? It would have been nice if
> Aircraft Spruce had included the Material Safety Data Sheet.
Here's an excerpt from my Web page
<http://members.xoom.com/frankv/bunny3c.htm> -- this page contains most
of what I learnt about fuel tank construction. Note that lots of it is
copies of stuff from the RV-list. Note that the message refers to
Thiokol MC-236 B-2 Fuel Tank Sealant which Vans now supply, rather than
to ProSeal. Not sure whether you have the real thing or the new stuff.
[start excerpt]
Fred Hiatt <hiat...@gold.tc.umn.edu> wrote to the RV-List: For those of
you using the tank sealant that Vans now ships, here is more information
than you may ever want to know.
After reading the note from Wayne Bonesteel about fuel tank sealant made
by Advanced Chemistry & Technology, Inc., I called Nick Champlin (if
desired, contact Tel: (714) 373-2837 Fax: (714) 373-1913) at the company
to learn more (us engineers are ever curious).
He gave me permission to forward the following info regarding the
Thiokol MC-236 B-2 Fuel Tank Sealant:
The material is made to pass Mil-S-8802 specification which among
other things requires a hard cure time of 40 hours maximum. (This stuff
is used on the
Stealth Bomber (B2) fuel tanks). Over time (years) the cure time
may be longer, HOWEVER, the mechanical properties (read strength) do NOT
change.
Working temperature affects the cure time also. For example, the
rule of thumb is that if the working temperature is 90 deg. F, (70
degrees being nominal) the
cure time can be 1/2 of the 40 hour spec., conversely, if the
working temperature is 50 degrees F, then the cure time can be 2X the 40
hour spec.
Storage temperature affects the nominal 40 hour cure time, that is,
it will extend slightly with time if stored at room temp. If the
material is stored in a freezer or
refrigerator, the added cure time will be small. They had some
material returned to them that had been on the shelf for several years
and the user had lost the
accelerator and wanted to know if they had accelerator that would
work with the old stuff. They mixed up a batch using the accelerator
that matched the batch
number, and they detected no change in the mechanical stability or
strength of the cured material.
The older Proseal had some additives in it which did affect the
mechanical properties over time. In addition, it would skin over in the
can because of these additives. By the way, Nick Champlin used to work
for the company that made(makes) Proseal.
The above info comes with no written or implied guarantee by myself or
Nick, however, after 25 years in the business he knows what he is
talking about.
[end excerpt]
HTH,
Frank.
--
fra...@ee.cit.ac.nz Frank van der Hulst
My home page is http://homepages.ihug.co.nz/~frankvdh
Nestorc
differs storage life and temperature.
Bruce A. Frank wrote in message <7u3bao$1ls$1...@bgtnsc03.worldnet.att.net>...
>Does anyone know what the pot life of mixed Pro Seal? Will refrigeration
>significantly extend the shelf life? Will freezing the unmixed polymer,
>for extended storage, cause any problems? It would have been nice if
>Aircraft Spruce had included the Material Safety Data Sheet.
Bruce A. Frank
>
> Please specify the Part No., It is because the different Sealants will have
> differs storage life and temperature.
>
P/S 890 B-2
Shelly
I don't have the MSDS handy, but we just finished our fuel tanks. A
warm day will cause the material to begin to stiffen in about an hour.
The cooler the day, the more setting time you have, but don't count on
more than 2 or 2 1/2 hrs. Clean with MEK, apply to only one surface,
don't smear too much (I made a small spreading spatula with .030
clearance). I had two helpers and we glued and riveted a 60 gal tank in
about 2 1/2 hrs.
Storage shouldn't be a problem. Mix what you are going to use, and then
make a new mix. I have used some stored at 70 degrees for over a year
and it seemed ok, but I would use fresh material on a fuel tank.
Shelly
John Kunkel
>
> Nestorc wrote:
> >
> > Please specify the Part No., It is because the different Sealants will have
> > differs storage life and temperature.
> >
>
> P/S 890 B-2
B-2 has a two hour working time at room temperature. Refrigerating will
increase the mixed working time and freezing will extend it for a long
time. I've used frozen and thawed sealant months later.
The manufacturers warn against placing the mixed sealant in reefers or
freezers with food products but I've been doing it for years with no ill
effects, effects, effects, effects..............
Jjjjohn
Bruce A. Frank
Frank van der Hulst wrote:
>
> "Bruce A. Frank" wrote:
> > Does anyone know what the pot life of mixed Pro Seal?
>
> Quite short -- a couple of hours.
>
> > Will refrigeration
> > significantly extend the shelf life?
>
> I think so.
>
> > Will freezing the unmixed polymer,
> > for extended storage, cause any problems? It would have been nice if
> > Aircraft Spruce had included the Material Safety Data Sheet.
>
--
Bruce A. Frank
Juan Jimenez (TeamB)
Nestorc wrote:
>
> Please specify the Part No., It is because the different Sealants will have
> differs storage life and temperature.
>
> Bruce A. Frank wrote in message <7u3bao$1ls$1...@bgtnsc03.worldnet.att.net>...
> >Does anyone know what the pot life of mixed Pro Seal? Will refrigeration
> >significantly extend the shelf life? Will freezing the unmixed polymer,
> >for extended storage, cause any problems? It would have been nice if
> >Aircraft Spruce had included the Material Safety Data Sheet.
Bruce A. Frank
>
> "Official" shelf life of pro-seal of the type you stated is 6 months.
>
one time which is why I asked about cold storage.
Craig C.
>Hi Bruce,
>Shelly
If you really need longer working times, then look for the B6 version.
It will give you a minimum working time of 5-6 hours. Routinely, we
used to shoot structure together on the F-16 with B1/2 that gave us
about 45 minutes of work time.
BTW, If you need a durable, but slightly flexible seal for inspection
panels and the like, I've got a fast method that is really great.
Using something like superglue, glue flat washers onto the back side
of the removeable panel at each screw location. Spray the entire back
side with mold release. Tape off the area around the cutout and
prepare the structure like you would if it were to be a riveted fuel
tank joint. Coat the area with a layer of the shortest life sealant
that you have. Layer should be at least 2x the washer thickness. Screw
the panel on, being careful to squeze out all the excess sealant and
not warp or distort the panel. Let cure for at least 24 hours. Remove
the screw and the panel, trim the sealant as required to give a neat
edge. Knock off the washers and you now have a perfect fitting, water
resistant gasket. Before you try this with your real parts, I strongly
suggest that you experiment with some scraps first. It takes a little
finessing to get everything just right, but you will be supprized at
how well it works. BTW, if you end up with small holes in the gasket,
simple sand the area a little and patch with a little more mixed up
sealant For information purposes, the stuff that we do this with on
the F-16 is Thiokol's FMS 1044 B-1/2.
Craig
Juan Jimenez (TeamB)
>
> As it says on the lable. I do not expect to use the entire pint can at
> one time which is why I asked about cold storage.
I can't speak for that, since I've never used it anywhere where it gets
cold. I used it to build a BD-5 but I built it when I was living in the
Caribbean. Sorry I can't be of more help. :(
Juan
Juan Jimenez (TeamB)
them in two sizes. The only thing I don't like about that is that 1) the
cartridges are way overpriced and 2) you have to have a dispensing gun
for it. Then again, it makes it much easier, and a heck of a lot less
messier, to deal with application of small qtys of the stuff.
Juan
Bruce A. Frank
>
> BTW, you can also buy Pro-Seal/PRC in cartridges. Aircraft Spruce has
> them in two sizes. The only thing I don't like about that is that 1) the
> cartridges are way overpriced and 2) you have to have a dispensing gun
> for it. Then again, it makes it much easier, and a heck of a lot less
> messier, to deal with application of small qtys of the stuff.
>
> Juan
Yeh, I thought about buying it that way. I've used the gun dispenser
with other types of glues and goos but the higher price of the Pro Seal
plus the additional cost of the gun turned me to the pint can.
Nestorc
-B2 means it need 2 curing hours, where as B1/2 need half hour.
If you are only need to use a bit, I will suggest you use the 1 pint / kit.
Before you mix the kit, make sure the weight ratio is correct. The room temp
(25 degree C) will be the best storage temp. If you are using for Fuel Tank
purpose, the alternated sealant will be PR1422. For more details, you can
contact the PRC agency.
Juan Jimenez (TeamB) wrote in message <380707D7...@home.com>...
>BTW, you can also buy Pro-Seal/PRC in cartridges. Aircraft Spruce has
>them in two sizes. The only thing I don't like about that is that 1) the
>cartridges are way overpriced and 2) you have to have a dispensing gun
>for it. Then again, it makes it much easier, and a heck of a lot less
>messier, to deal with application of small qtys of the stuff.
>
>Juan
>
Charles Downing
you won't be able to work it. then it will be final cure a specified time
later.
The B-2 used very little B1/2, mostly B2 or longer, and then it was for fay
surface seal mostly. They also used type A for brush coatings, along with
some Type C, but then to know where and when to use which one required the
drawing and spec sheets.
Also the cost of adding the MSDS to a catalog would greatly increase the
Catalog Costs. Most manufacturers includ a copy of that chemical's MSDS in
the container or at least they should. I think it is a fed. reqmnt
-**** Posted from RemarQ, http://www.remarq.com/?b ****-
Real Discussions for Real People
Bruce A. Frank
>
> The number in the sealant in reality means a tack free condition in which
> you won't be able to work it. then it will be final cure a specified time
> later.
>
> The B-2 used very little B1/2, mostly B2 or longer, and then it was for fay
> surface seal mostly. They also used type A for brush coatings, along with
> some Type C, but then to know where and when to use which one required the
> drawing and spec sheets.
I am building a fuel tank in which the filler neck is riveted rather
than welded (to prevent distorsion of the airfoil shaped top surface).
My design. My choices (mistakes?) to be made.
>
> Also the cost of adding the MSDS to a catalog would greatly increase the
> Catalog Costs. Most manufacturers includ a copy of that chemical's MSDS in
> the container or at least they should. I think it is a fed. reqmnt
I also thought it was a requirement to include a copy of MSDS in the
shipping packaging. They did include a new catalog.
highflyer
>
> Juan Jimenez (TeamB) wrote:
> >
> > "Official" shelf life of pro-seal of the type you stated is 6 months.
> >
> one time which is why I asked about cold storage.
>
I think the MSDS does mention that cold storage significantly extends
the
shelf life. You do want to avoid freezing it though. I think I have a
couple of cans of it in my hangar fridge right now, right behind the
Budweiser.
HighFlyer
Highflight Aviation Services
Juan Jimenez (TeamB)
Juan
Nestorc
know the product data, you need to read from the Data Sheet or the PRC
Product Manual.
An unofficial method to reduce the cure time is slightly increase the
hardener ratio. To keep the Proseal inside the freeze will not have any
function, the storage temperature is recommended on the manufacturer label.
Charles Downing wrote in message ...
>The number in the sealant in reality means a tack free condition in which
>you won't be able to work it. then it will be final cure a specified time
>later.
>
>The B-2 used very little B1/2, mostly B2 or longer, and then it was for fay
>surface seal mostly. They also used type A for brush coatings, along with
>some Type C, but then to know where and when to use which one required the
>drawing and spec sheets.
>
>Also the cost of adding the MSDS to a catalog would greatly increase the
>Catalog Costs. Most manufacturers includ a copy of that chemical's MSDS in
>the container or at least they should. I think it is a fed. reqmnt
>
>
>