PR1422

Jason Beall · Post by **Jason Beall** » Fri Feb 17, 2012 10:17 pm

Hi all,

I have purchased some P1422 fuel tank sealant here in
the UK. Does anyone know what the mixing ratio for
this stuff is? No instructions came with it and the
distributor seems to be clueless!

Thanks,

Jason

=====
________________________________________________

Jason Beall
Super Rebel No. 131
Aberdeen, Scotland, UK
super_rebel131@yahoo.com

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Legeorgen · Post by **Legeorgen** » Fri Feb 17, 2012 10:17 pm

Jason,

you should be very careful what sealant you put in your tank. Contact the manufacturer for specs and instructions. This is an area where you don't want problems while flying. Fuel starvation is the number one cause of engine stoppage in general aviation engine failures and forced landings.

Many sealant have been known to delimitate from the tank and can plug your finger strainer. Especially if you use auto fuels with Alcohol. Better to be safe.

Bruce G 357R

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klehman · Post by **klehman** » Fri Feb 17, 2012 10:17 pm

Recommend you check the prc web site.
Ken

Jason Beall wrote:

Hi all,

I have purchased some P1422 fuel tank sealant here in
the UK. Does anyone know what the mixing ratio for
this stuff is? No instructions came with it and the
distributor seems to be clueless!

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Warren Montgomery · Post by **Warren Montgomery** » Fri Feb 17, 2012 10:17 pm

<!doctype html public "-//w3c//dtd html 4.0 transitional//en"> Jason,
Mixing is 10-1 by weight. As the density is near enough the same get a 50cc syringe (try the Vet) and a 5cc syringe fill then mix by volume 10-1.
If mixing large quantities you can use a scale but the syringes are great as you mix a lot of small quantities.
http://www.prc-desoto.com/
Having built the normal 80 gal tanks then ripped the wings apart and increased to 120 gal I'm probably only second to Wayne, BobP and a couple of others on PR usage. I've used PRC-Desoto Qts/Pts & 103ml kits. PS 890 first time PR 1422 second time
PR 1422 is an Airbus spec'd Desoto sealant good for avgas, A1 & Alcohol so it's also good for Mogas which may have up to 10% alcohol in Canada.
PS 890 also Desoto is similar but is a Boeing spec'd. This is what MAM first supplied.
Note 890 & 1422 need a primer to bond to each other.
890 finishes Black-- White base, black hardener
1422 finishes Dark Brown-- Rust Brown base, black hardener
A is brushable
B is for fillets
C is for Faying (between two surfaces) viscosity between A & B,
I asked Desoto if you can mix A & B to get Cish and the answer is no as the hardeners are custom blended to the batch.
The number following the letter is application time.
1422 only comes in 1/2 and 2 hour
890 is 1/2 to 8 hours in A and B and I believe up to 20 hours in C
C4 or C8 would be ideal for joining the tank skins but C is mainly only used in production so hard to get.
Second choice would be B4 or B8.
Most likely you'll have to use B2
Every +/-10F from 70F halves or doubles the application time. Colder means more application time.
Surfaces must be scotch brited, then cleaned with strong solvent such as MEK, Acetone etc. (We all know the bad things about MEK though)
Dry wipe immediately following wet wipe, May need three cleanings on contact areas.
Do not touch afterwards with skin as oils will contaminate surface.
Apply PR to both surfaces using spatula or rollor. More is not nessisarily better, however it's comforting to see some ooze out.
Roll rivets in PR before inserting.
If you get tits hanging off the inside of rivets just leave until it sets then pull off otherwise you'll have a bigger mess.
I removed all mine before covering with 'A' as I didn't want falling off at later date.
Cleaned outside with Acetone. It's gonna be messy.
Another trick is to mask off areas you don't want sealant on.
Buy a couple of boxes of surgical gloves.
Tongue depressors and popsicle sticks also come in handy.
Ensure you have at least one extra set of hands as time is criticle.
I put 'A' on the internal side of the rivets. The quickest way was to steal the wife's icing applicator with disposable bags (think she'll notice?), I then put a short tube on the end just bigger then the set rivet and put tube over rivet squeezed and presto rivet was covered. This worked especially well when I had to work through the access holes. Note the 3500 uses 5/32 & 3/16 non tank rivets along the spar. I also used 1412 flush rivets on the top tank skin and treated similar. To be sure to be sure I even filled all the non tank rivet mandrel holes from the outside with 1422, this time using a syringe. The icing applicator also works great for filleting. Actually I found the cut off top of a glue bottle male/female parts worked best with the icing bag. Of course I figured this out after I'd coated all her nozzles with PR. Just don't coat your 'nozzle'.
Sorry to say but it's gonna be slow, tiring and very messy but hey you only do it once right?
You know there's always that one guy who offers to help but you don't really want him to. Now's your chance to kill two birds with one stone.
Get him to help with this and he'll never be back. ;-)
Good luck
Warren
Moose 029 [quote] [quote]Date: Fri, 5 Jul 2002 07:03:43 -0700 (PDT)
From: super_rebel131@yahoo.com
To: murphy-rebel
Subject: PR1422

Hi all,

I have purchased some P1422 fuel tank sealant here in
the UK. Does anyone know what the mixing ratio for
this stuff is? No instructions came with it and the
distributor seems to be clueless!

Thanks,

Jason Beall · Post by **Jason Beall** » Fri Feb 17, 2012 10:17 pm

Thanks Warren!

-Jason

--- Warren Montgomery <monty@emirates.net.ae> wrote:

Jason,

Mixing is 10-1 by weight. As the density is near
enough the same get a 50cc syringe (try the Vet) and
a 5cc syringe fill then mix by volume 10-1.
If mixing large quantities you can use a scale but
the syringes are great as you mix a lot of small
quantities.

http://www.prc-desoto.com/

Having built the normal 80 gal tanks then ripped the
wings apart and increased to 120 gal I'm probably
only second to Wayne, BobP and a couple of others on
PR usage. I've used PRC-Desoto Qts/Pts & 103ml kits.
PS 890 first time PR 1422 second time

PR 1422 is an Airbus spec'd Desoto sealant good for
avgas, A1 & Alcohol so it's also good for Mogas
which may have up to 10% alcohol in Canada.
PS 890 also Desoto is similar but is a Boeing
spec'd. This is what MAM first supplied.

Note 890 & 1422 need a primer to bond to each other.
890 finishes Black-- White base, black hardener
1422 finishes Dark Brown-- Rust Brown base, black
hardener

A is brushable
B is for fillets
C is for Faying (between two surfaces) viscosity
between A & B,
I asked Desoto if you can mix A & B to get Cish and
the answer is no as the hardeners are custom blended
to the batch.
The number following the letter is application time.

1422 only comes in 1/2 and 2 hour
890 is 1/2 to 8 hours in A and B and I believe up to
20 hours in C

C4 or C8 would be ideal for joining the tank skins
but C is mainly only used in production so hard to
get.
Second choice would be B4 or B8.
Most likely you'll have to use B2

Every +/-10F from 70F halves or doubles the
application time. Colder means more application
time.

Surfaces must be scotch brited, then cleaned with
strong solvent such as MEK, Acetone etc. (We all
know the bad things about MEK though)
Dry wipe immediately following wet wipe, May need
three cleanings on contact areas.
Do not touch afterwards with skin as oils will
contaminate surface.

Apply PR to both surfaces using spatula or rollor.
More is not nessisarily better, however it's
comforting to see some ooze out.

Roll rivets in PR before inserting.
If you get tits hanging off the inside of rivets
just leave until it sets then pull off otherwise
you'll have a bigger mess.
I removed all mine before covering with 'A' as I
didn't want falling off at later date.
Cleaned outside with Acetone. It's gonna be messy.
Another trick is to mask off areas you don't want
sealant on.
Buy a couple of boxes of surgical gloves.
Tongue depressors and popsicle sticks also come in
handy.

Ensure you have at least one extra set of hands as
time is criticle.

I put 'A' on the internal side of the rivets. The
quickest way was to steal the wife's icing
applicator with disposable bags (think she'll
notice?), I then put a short tube on the end just
bigger then the set rivet and put tube over rivet
squeezed and presto rivet was covered. This worked
especially well when I had to work through the
access holes. Note the 3500 uses 5/32 & 3/16 non
tank rivets along the spar. I
also used 1412 flush rivets on the top tank skin and
treated similar. To be sure to be sure I even filled
all the non tank rivet mandrel holes from the
outside with 1422, this time using a syringe. The
icing applicator also works great for filleting.
Actually I found the cut off top of a glue bottle
male/female parts worked best with the icing bag. Of
course I figured this out after I'd coated all her
nozzles with
PR. Just don't coat your 'nozzle'.

Sorry to say but it's gonna be slow, tiring and very
messy but hey you only do it once right?

You know there's always that one guy who offers to
help but you don't really want him to. Now's your
chance to kill two birds with one stone.
Get him to help with this and he'll never be back.
;-)

Good luck
Warren
Moose 029

Date: Fri, 5 Jul 2002 07:03:43 -0700 (PDT)
From: super_rebel131@yahoo.com
To: murphy-rebel
Subject: PR1422

Hi all,

I have purchased some P1422 fuel tank sealant here
in
the UK. Does anyone know what the mixing ratio for
this stuff is? No instructions came with it and
the
distributor seems to be clueless!

Thanks,

Jason

=====
________________________________________________

Jason Beall
Super Rebel No. 131
Aberdeen, Scotland, UK
super_rebel131@yahoo.com

__________________________________________________
Do You Yahoo!?
Sign up for SBC Yahoo! Dial - First Month Free
http://sbc.yahoo.com

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