Geoff,
What is the maximum thickness liquid EPDM you have cast? I've approached
1/4" in four separate 'lifts', letting each nearly cure before adding more
and spinning the casing.
Edward
On Fri, Aug 24, 2018 at 10:50 AM Geoff Huber <geoff.huber@xxxxxxxxx> wrote:
I have lined a tube before by first applying light coat of liquid EPDM to
the case, the applying a sheet that fit the inside, then applied more
liquid EPDM to the seam to fill it. Then cast directly into the case. I
did this in areas where I needed more heat protection then the straight
liquid EPDM coating would provide.
G
On Fri, Aug 24, 2018 at 7:42 AM Edward Wranosky <edwardcw@xxxxxxxxx>
wrote:
Bill,
Would rolling in some liquid EPDM between the gap work? I'm thinking
that you grease the liner and insert from both ends, leaving a gap of 2-3
inches between them in the middle. Pour in some liquid EPDM and spin to
coat the area liberally. Then rotate the work and push the liner into the
final location and it will ooze a bit of EPDM and fill the joint. Then
clean up the majority and spin to cure everything.
Edward
On Fri, Aug 24, 2018 at 8:13 AM William Claybaugh <wclaybaugh2@xxxxxxxxx>
wrote:
Troy:
I agree that hot gas is unlikely (1-2 out of five) but the consequence
is loss of a five figure asset (5 out of 5). This is a bit like the “too
big to fail” problem: if it was a hundred dollar motor I’d just test it and
see what happens; at $10,000 plus I’m given to making certain there is no
gas path.
Unfortunately, the liner tubes come in 36” lengths which means there is
insufficient leftover material to do as you suggest; in addition, having a
seam at the seal does leave a theoretical leak point. Again, the odds of
that being an issue seem very low...but the consequence of failure is very
high.
I—very briefly—considered ordering a phenolic tube to slip fit the joint
but the minimum order is near US$1,000 and provides enough material to just
make BATES grains...a solution to be sure but adding cost and reducing
performance (by 3% compared to a case bonded grain).
Bill
On Thu, Aug 23, 2018 at 9:32 PM Troy Prideaux <
troy@xxxxxxxxxxxxxxxxxxxxx> wrote:
Cut off a piece of liner tube, cut a wide enough slice out from the that
piece's perimeter so that you can fit the closed up piece snuggly
inside the
liner tubes and bond in place with plenty of HTPB/Tepanol/curative mix.
You
can hopefully join the 2 liner pieces together piece by piece so
there's no
stretching or reaching and keep in mind the chances of hot gas getting
to
this point is quite remote, especially if there's minimal clearance
between
the liner and casing ie. the casing wall will absorb lots of heat fast,
the
flow will be extremely momentary and minimal and if both ends of the
liner-casing clearance were exposed, the middle section should stay
quite
stagnant anyway.
Troy
-----Original Message-----arocket-bounce@xxxxxxxxxxxxx]
From: arocket-bounce@xxxxxxxxxxxxx [mailto:
On Behalf Of John Stoffeltube,
Sent: Friday, 24 August 2018 12:51 PM
To: arocket@xxxxxxxxxxxxx
Subject: [AR] Re: Sealing phenolic liner joints
For the bonding, you don't need to actually put the liners into the
just
into a short enough length where you can get it more easily. If youcan
take a
piece of pipe the same inside diameter, and cut it in half, then youcould
possibly use those halves a molds.maybe
Crack it open, lay in the liner, but the joints with whatever (I'd
try to
scarf them and glue with epoxy) aand then put the other half on,clamp it
shut
and put in the bladder in the inside to push out.work.
The scarf could be 3/4" long, or possbily longer if you can make it
Or if
the liners are already in tube form, just a short section of theoutside
needs to
be supporting the joint when you butt them and glue them together.
John