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