Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work.

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PhysicsGenius
 
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http://physeeks.dyndns.org:8000/ging.../foundry.xhtml

Since I have no welder to attach a plate to a pipe, I got the pipe
nipple and endcap for my Gingery crucible. Got them home, put them
together and poured some water in to get a more exact volume
measurement. Water all over the floor. Now some are suggesting I need
to weld it. I do not, repeat, do not have a welder.

I couldn't tighten the endcap on all the way by hand. If I somehow
managed to get it on all the way, would it be water (and, more
importantly, aluminum) tight? How would I tighten it that far, when the
endcap is about 5 inches across?
  #2   Report Post  
Ecnerwal
 
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PhysicsGenius wrote:

I do not, repeat, do not have a welder.


But I'd bet there are several weldors (with welders) listed in the phone
book for your area. Should not cost much, should not take long.

Dribbling hot aluminum on yourself will cost a good deal more, and the
pain will be actual, rather than the imaginary pain from opening your
wallet.

--
Cats, Coffee, Chocolate...vices to live by
  #3   Report Post  
Tim Williams
 
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"PhysicsGenius" wrote in message
news
I couldn't tighten the endcap on all the way by hand. If I somehow
managed to get it on all the way, would it be water (and, more
importantly, aluminum) tight? How would I tighten it that far, when the
endcap is about 5 inches across?


I don't see why (or how) it wouldn't. Pipe threads are made to seal...
As-is, the high surface tension of aluminum would probably hold it in,
especially with a nice heavy layer of scale which you need to toast onto it
first anyway. (Try for a good orange heat over the whole thing, minimum.)
Aluminum just doesn't tend to flow through pores.
'Course, "probably" isn't good enough, so find some nice monkey wrenches,
tighten it up, toast it, see if that works.

Tim

--
"That's for the courts to decide." - Homer Simpson
Website @ http://webpages.charter.net/dawill/tmoranwms


  #4   Report Post  
Glenn Lyford
 
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I couldn't tighten the endcap on all the way by hand. If I somehow
managed to get it on all the way, would it be water (and, more
importantly, aluminum) tight? How would I tighten it that far, when
the endcap is about 5 inches across?


I don't see why (or how) it wouldn't. Pipe threads are made to
seal...


Thread friction in that size is a lot. Consider a turn of
teflon tape or teflon thread sealer. Not so much to act
as a sealer in and of itself, but to lubricate the threads
enough to really torque the cap down to get a good seal.
For a cap that size, a vice and a serious pipe wrench is in
order. I would be tempted to say that it is not possible
to overtighten it with hand tools...

--Glenn Lyford
  #5   Report Post  
JTMcC
 
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"PhysicsGenius" wrote in message
news
http://physeeks.dyndns.org:8000/ging.../foundry.xhtml

Since I have no welder to attach a plate to a pipe, I got the pipe
nipple and endcap for my Gingery crucible. Got them home, put them
together and poured some water in to get a more exact volume
measurement. Water all over the floor. Now some are suggesting I need
to weld it. I do not, repeat, do not have a welder.

I couldn't tighten the endcap on all the way by hand. If I somehow
managed to get it on all the way, would it be water (and, more
importantly, aluminum) tight? How would I tighten it that far, when the
endcap is about 5 inches across?


Not that I consider myself a "smart guy", but I would truck it on down to
the local welding shop and have them run a seal pass around it. This is
going to be cheaper than buying the large size wrenches and vise needed to
crank that cap on.
Unless of course you know someone with 4' pipe wrenches.

JTMcC.






  #6   Report Post  
Dave Keith
 
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I know I don't have a 4' pipe wrench ! But I tend to agree with another
poster who thought that molten Al doesn't flow well into cracks and
crevices. When we poured the split-nut in Al (not recommended) it barely
formed the 3/8-16 threads.

Dave

"JTMcC" wrote in message
...

"PhysicsGenius" wrote in message
news
http://physeeks.dyndns.org:8000/ging.../foundry.xhtml

Since I have no welder to attach a plate to a pipe, I got the pipe
nipple and endcap for my Gingery crucible. Got them home, put them
together and poured some water in to get a more exact volume
measurement. Water all over the floor. Now some are suggesting I need
to weld it. I do not, repeat, do not have a welder.

I couldn't tighten the endcap on all the way by hand. If I somehow
managed to get it on all the way, would it be water (and, more
importantly, aluminum) tight? How would I tighten it that far, when the
endcap is about 5 inches across?


Not that I consider myself a "smart guy", but I would truck it on down to
the local welding shop and have them run a seal pass around it. This is
going to be cheaper than buying the large size wrenches and vise needed to
crank that cap on.
Unless of course you know someone with 4' pipe wrenches.

JTMcC.






  #7   Report Post  
Bob May
 
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Get a wrench to tighten the end cap. If you have a torch, you also will do
well to heat the endcap and quickly put it onto the nipple and that will
make things even more tight. Don't use teflon tape or any other thing like
that as the tape will evaporate the first time that the thing is used.

--
Bob May
Losing weight is easy! If you ever want to lose weight, eat and drink less.
Works every time it is tried!


  #8   Report Post  
PhysicsGenius
 
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This brings up another point. Even if I torque it on there really well,
what happens when the whole thing heats up in the furnace? Is the
bottom going to fall off?

Man, I am so stupid for not having thought of any of this before.

Bob May wrote:
Get a wrench to tighten the end cap. If you have a torch, you also will do
well to heat the endcap and quickly put it onto the nipple and that will
make things even more tight. Don't use teflon tape or any other thing like
that as the tape will evaporate the first time that the thing is used.

--
Bob May
Losing weight is easy! If you ever want to lose weight, eat and drink less.
Works every time it is tried!


  #9   Report Post  
Jeff Wisnia
 
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Tim Williams wrote:

snipped

"PhysicsGenius" wrote in message


I don't see why (or how) it wouldn't. Pipe threads are made to seal...
As-is, the high surface tension of aluminum would probably hold it in,


I'd side with you on the surface tension thing, but I gotta jump on your
statement that pipe threads "are made to seal..."

They're not, unless they're the somewhat rare "dryseal" or "fuel service"
thread form.

Regular NPT pipe threads cut to spec have a built in "spiral leak path" along
the crests of the threads, and won't seal under normal torquing unless some
sort of sealant, pipe dope or tape, is employed. A glance at the thread form
diagrams in Machinery's Handbook will confirm that.

The "dryseal" threads are made with a thread form which seals tight through
minor deformation of the metal parts. They are usually found on brass parts to
enable that to happen easily. They were developed back when the available pipe
dopes didn't stand up to petroleum products and solvents too well. Nowadays,
teflon tape will enable regular NPT threads to seal many of those fluids ok.

Just my .02,

Jeff


especially with a nice heavy layer of scale which you need to toast onto it
first anyway. (Try for a good orange heat over the whole thing, minimum.)
Aluminum just doesn't tend to flow through pores.
'Course, "probably" isn't good enough, so find some nice monkey wrenches,
tighten it up, toast it, see if that works.

Tim

--
"That's for the courts to decide." - Homer Simpson
Website @ http://webpages.charter.net/dawill/tmoranwms





--
Jeff Wisnia (W1BSV + Brass Rat '57 EE)

"If you can keep smiling when things go wrong, you've thought of someone to
place the blame on."


  #10   Report Post  
MikeM
 
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Default OK, smart guys

PhysicsGenius wrote in message ...
http://physeeks.dyndns.org:8000/ging.../foundry.xhtml

Since I have no welder to attach a plate to a pipe, I got the pipe
nipple and endcap for my Gingery crucible. Got them home, put them
together and poured some water in to get a more exact volume
measurement. Water all over the floor. Now some are suggesting I need
to weld it. I do not, repeat, do not have a welder.

I couldn't tighten the endcap on all the way by hand. If I somehow
managed to get it on all the way, would it be water (and, more
importantly, aluminum) tight? How would I tighten it that far, when the
endcap is about 5 inches across?





Not sure if aluminum will leak through a threaded joint but I don't
think I would risk it. Aluminum can leak through some surprisingly
small holes. My first melting pot was a section of 4" pipe with a
plate welded onto the end, fired it 4 times and it developed a pinhole
in the bottom. The hole was so small it was hard to see but it was
enough to let much of the contents run out into the furnace. Now I use
a cast iron pot coated inside & out with furnace cement (the dark gray
paste type) thinned with water to a paint, and the coated pot dried
over a heat element before use.
Mike


  #11   Report Post  
Steve Smith
 
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Default OK, smart guys

Why don't you buy a real crucible?

Steve Smith


PhysicsGenius wrote:

This brings up another point. Even if I torque it on there really
well, what happens when the whole thing heats up in the furnace? Is
the bottom going to fall off?

Man, I am so stupid for not having thought of any of this before.

Bob May wrote:

Get a wrench to tighten the end cap. If you have a torch, you also
will do
well to heat the endcap and quickly put it onto the nipple and that will
make things even more tight. Don't use teflon tape or any other
thing like
that as the tape will evaporate the first time that the thing is used.

--
Bob May
Losing weight is easy! If you ever want to lose weight, eat and
drink less.
Works every time it is tried!



  #12   Report Post  
Tim Williams
 
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"Jeff Wisnia" wrote in message
...
Regular NPT pipe threads cut to spec have a built in "spiral leak path"

along
the crests of the threads, and won't seal under normal torquing unless

some
sort of sealant, pipe dope or tape, is employed. A glance at the thread

form
diagrams in Machinery's Handbook will confirm that.


Ah yes, that's true. I wonder how dopey scale is...
I doubt aluminum would get very far up the spiral, of course. And even if
it made two turns, it still has a ways to go.

The "dryseal" threads are made with a thread form which seals tight

through
minor deformation of the metal parts. They are usually found on brass

parts to
enable that to happen easily.


Would that be the brass 1/4" MPT fittings I use on my propane?

Tim

--
"That's for the courts to decide." - Homer Simpson
Website @ http://webpages.charter.net/dawill/tmoranwms


  #13   Report Post  
PhysicsGenius
 
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Because then I'd have two additional problems:

1) I'd have to buy a real tongs, too. (I understand ceramic crucibles
are fragile.)

2) I'd have to keep buying crucibles as they break.

Steve Smith wrote:
Why don't you buy a real crucible?

Steve Smith


PhysicsGenius wrote:

This brings up another point. Even if I torque it on there really
well, what happens when the whole thing heats up in the furnace? Is
the bottom going to fall off?

Man, I am so stupid for not having thought of any of this before.

Bob May wrote:

Get a wrench to tighten the end cap. If you have a torch, you also
will do
well to heat the endcap and quickly put it onto the nipple and that will
make things even more tight. Don't use teflon tape or any other
thing like
that as the tape will evaporate the first time that the thing is used.

--
Bob May
Losing weight is easy! If you ever want to lose weight, eat and
drink less.
Works every time it is tried!



  #14   Report Post  
Backlash
 
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Default OK, smart guys

Man, you're not stupid, you're LEARNING! Stop beating yourself up

RJ

"PhysicsGenius" wrote in message
...
This brings up another point. Even if I torque it on there really well,
what happens when the whole thing heats up in the furnace? Is the
bottom going to fall off?

Man, I am so stupid for not having thought of any of this before.

Bob May wrote:
Get a wrench to tighten the end cap. If you have a torch, you also will

do
well to heat the endcap and quickly put it onto the nipple and that will
make things even more tight. Don't use teflon tape or any other thing

like
that as the tape will evaporate the first time that the thing is used.

--
Bob May
Losing weight is easy! If you ever want to lose weight, eat and drink

less.
Works every time it is tried!




  #15   Report Post  
jim
 
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Default OK, smart guys

trPhysicsGenius wrote:

http://physeeks.dyndns.org:8000/ging.../foundry.xhtml

Since I have no welder to attach a plate to a pipe, I got the pipe
nipple and endcap for my Gingery crucible. Got them home, put them
together and poured some water in to get a more exact volume
measurement. Water all over the floor. Now some are suggesting I need
to weld it. I do not, repeat, do not have a welder.

I couldn't tighten the endcap on all the way by hand. If I somehow
managed to get it on all the way, would it be water (and, more
importantly, aluminum) tight? How would I tighten it that far, when the
endcap is about 5 inches across?

take your two pipe wrenches and with the endcap on tne short piece of
pipe you lay the endcap down with the short pipe standing up on a
workbench... then nail the endcap to the workbench with about 15 large
nails.. then take two pipe wrenches and open each one about 1/2 inch and
put them over the sides of the short pipe at 180 apart and then start to
twist the short pipe into the endcap....


  #16   Report Post  
Jeff Wisnia
 
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Default OK, smart guys



Tim Williams wrote:
snipped

The "dryseal" threads are made with a thread form which seals tight

through
minor deformation of the metal parts. They are usually found on brass

parts to
enable that to happen easily.


Would that be the brass 1/4" MPT fittings I use on my propane?


I assume you meant "NPT fittings".

The answer is that the "dryseal" threads are designated as NPTF, with the "F"
originally signifying "fuel", but there's no way I can tell from here if
that's what you've got, you'd have to compare the thread form with the specs.

Jeff



Tim

--
"That's for the courts to decide." - Homer Simpson
Website @ http://webpages.charter.net/dawill/tmoranwms


--

Jeff Wisnia (W1BSV + Brass Rat '57 EE)

"If you can smile when things are going wrong, you've thought of someone to
blame it on."


  #17   Report Post  
Don Foreman
 
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Default OK, smart guys

On Thu, 22 Jan 2004 14:38:27 GMT, PhysicsGenius
wrote:

http://physeeks.dyndns.org:8000/ging.../foundry.xhtml

Since I have no welder to attach a plate to a pipe, I got the pipe
nipple and endcap for my Gingery crucible. Got them home, put them
together and poured some water in to get a more exact volume
measurement. Water all over the floor. Now some are suggesting I need
to weld it. I do not, repeat, do not have a welder.

I couldn't tighten the endcap on all the way by hand. If I somehow
managed to get it on all the way, would it be water (and, more
importantly, aluminum) tight? How would I tighten it that far, when the
endcap is about 5 inches across?


If you were to post your general location, there may be an RCM reader
not far away who would offer to weld it for you.

  #18   Report Post  
Sunworshiper
 
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Default OK, smart guys

On Thu, 22 Jan 2004 14:38:27 GMT, PhysicsGenius
wrote:

http://physeeks.dyndns.org:8000/ging.../foundry.xhtml

Since I have no welder to attach a plate to a pipe, I got the pipe
nipple and endcap for my Gingery crucible. Got them home, put them
together and poured some water in to get a more exact volume
measurement. Water all over the floor. Now some are suggesting I need
to weld it. I do not, repeat, do not have a welder.

I couldn't tighten the endcap on all the way by hand. If I somehow
managed to get it on all the way, would it be water (and, more
importantly, aluminum) tight? How would I tighten it that far, when the
endcap is about 5 inches across?


Isn't the end cap cast iron? If so, that's not going to be easy to
weld. Try going to a welder and ask him to make one for you , they
will probably have the material right in the shop. Doesn't hurt to
ask , you could run into a very nice person and will do it cheap.
If not you can come back and tell us "They want *%# $xxx.xx to do it!"

  #19   Report Post  
Don Foreman
 
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Default OK, smart guys

On Sat, 24 Jan 2004 01:06:34 GMT, Sunworshiper
wrote:

Isn't the end cap cast iron? If so, that's not going to be easy to
weld. Try going to a welder and ask him to make one for you , they
will probably have the material right in the shop. Doesn't hurt to
ask , you could run into a very nice person and will do it cheap.
If not you can come back and tell us "They want *%# $xxx.xx to do it!"


Cast iron pipe parts aren't hard to weld with nickel rod, but I agree
with you that a visit to a weldor (pro or am) is the way to go here.

I'd happily do it for a sixpack if a guy in my area (Mnpls) showed
up with the materials in hand. Fitch would rather have a pound of
Kona coffee than a sixpack, but I've no doubt that he'd gladly do it
wiith or without the coffee. I think most RCM'ers with the right
equipment and skills (which includes many of us) would be glad to
help.

Scrap steel yards often have circular "drops" of 1/4" to 3/8" steel
from their plasma cutter, bits left from cutting holes. They
typically run 40 cents a pound on 2d Ave No. in Mnpls. A 6" round
drop of 5/16" would be a buck or two. It wouldn't take 5 minutes to
weld that on to the end of a piece of pipe.

  #20   Report Post  
Rusty Bates
 
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Default OK, smart guys

Mr. PG,

Glad to see your web site is finally functional for most of us to
visit. A couple of thoughts come to mind, first that retro-60's floor
you mention is the same type in my own kitchen. The same type of floor
my lovely wife complains about every day of the week. I happen to like
it but that is a different story. :-) The cope and drag box you have
built is nice but have you considered how much that rascle will weigh
once loaded with sand or petrobond? I have a few C&D boxes that size
that I use and the weight is around 80 to 100 pounds easily when
filled. They are gut busters trying to move by yourself to the pouring
area. Might I suggest building a smaller C&D frame to try first as
more than likely your first attempts will be small parts.

I'm glad to see you are trying to learn a new skill (learning to
casting alumimum and brass is one of the best things I've ever done)
but cheaping out on the crucible design is not the way to go my
friend. The pipe and cap should work (until you get a better feel for
the whole process)if the cap is welded to the pipe. You are correct in
that the clay-graphite crucibles are somewhat fragile and deteriorate
with useage and age. These also require correct fitting lifting tongs
and and good pouring shank to prevent damage to the crucible. Even
then, there is always a chance of breakage during the pouring process.
As others have already mentioned, molten metal of any sort will ruin
your day and other parts of your body given half a chance. I have made
over 300 pours (from 1 to 30 pounds of aluminum at a time on a hobby
basis) in the past 7 years and I still get very nervous when handling
a molten charge. Believe it or not many of us lurkers and posters to
this group do not want see anyone get hurt and there are a few of us
here who have been down the road you now travel. Spend the extra 30-40
bucks and get that cap welded to the bottom of that pipe! As someone
pointed out a few extra dollars spent will be nothing compared to the
medical bills you will get from burnt body parts. Please don't take
this posting as flame as its not meant as such. Good luck!

Rusty
W-S.NC





PhysicsGenius wrote in message ...
http://physeeks.dyndns.org:8000/ging.../foundry.xhtml

Since I have no welder to attach a plate to a pipe, I got the pipe
nipple and endcap for my Gingery crucible. Got them home, put them
together and poured some water in to get a more exact volume
measurement. Water all over the floor. Now some are suggesting I need
to weld it. I do not, repeat, do not have a welder.

I couldn't tighten the endcap on all the way by hand. If I somehow
managed to get it on all the way, would it be water (and, more
importantly, aluminum) tight? How would I tighten it that far, when the
endcap is about 5 inches across?



  #21   Report Post  
PhysicsGenius
 
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Default OK, smart guys

Rusty Bates wrote:
Mr. PG,

Glad to see your web site is finally functional for most of us to
visit. A couple of thoughts come to mind, first that retro-60's floor
you mention is the same type in my own kitchen. The same type of floor
my lovely wife complains about every day of the week. I happen to like
it but that is a different story. :-) The cope and drag box you have
built is nice but have you considered how much that rascle will weigh
once loaded with sand or petrobond? I have a few C&D boxes that size
that I use and the weight is around 80 to 100 pounds easily when
filled. They are gut busters trying to move by yourself to the pouring
area. Might I suggest building a smaller C&D frame to try first as
more than likely your first attempts will be small parts.


I like the floor pattern, but the color just sucks the photons right out
of the air.

Yes, I meant to build a smaller one, but I absentmindedly measured out
the boards for the larger flask that I'll need--I should probably build
the smaller one, too, first.. Still, being 6'2" and 250 lb, I could
probably manage to heave it over semi-gently.

I'm glad to see you are trying to learn a new skill (learning to
casting alumimum and brass is one of the best things I've ever done)
but cheaping out on the crucible design is not the way to go my
friend. The pipe and cap should work (until you get a better feel for
the whole process)if the cap is welded to the pipe. You are correct in
that the clay-graphite crucibles are somewhat fragile and deteriorate
with useage and age. These also require correct fitting lifting tongs
and and good pouring shank to prevent damage to the crucible. Even
then, there is always a chance of breakage during the pouring process.
As others have already mentioned, molten metal of any sort will ruin
your day and other parts of your body given half a chance. I have made
over 300 pours (from 1 to 30 pounds of aluminum at a time on a hobby
basis) in the past 7 years and I still get very nervous when handling
a molten charge. Believe it or not many of us lurkers and posters to
this group do not want see anyone get hurt and there are a few of us
here who have been down the road you now travel. Spend the extra 30-40
bucks and get that cap welded to the bottom of that pipe! As someone
pointed out a few extra dollars spent will be nothing compared to the
medical bills you will get from burnt body parts. Please don't take
this posting as flame as its not meant as such. Good luck!


I had made up my mind to return the nipple, but now I've called around
and nobody seems to have cast iron pots, which was my only other option.
It sounds like you wouldn't recommend me dipping into my vast quantity
of largish steel cans (formerly filled with crushed tomatoes) as a
source of disposable, one-time crucibles.

So let's say, for the sake of argument, that I find someone to weld this
for me. First of all, where should they weld it? If they do the
outside joint, isn't aluminum going to sneak up the inside and crack it
open via expansion and contraction? Will they be able to reach inside
and weld the inside joint?

Second, am I going to be able to drill holes in the nipple itself to
make some lifting holes? I understand that I should be able to drill
steel with a regular twist bit and my father-in-law has a drill press so
the shape isn't a problem, but this seems like a big job for regular
tools.

Hold it, I'm being stupid again. If I'm going to visit a welder, I
could just have him attach some hooks for me. Then I just forge some
hooks from rebar or steel rod and I'm golden.

Anyone here in the southern NH region that can do a little welding for
me in exchange for something?
  #22   Report Post  
Don Foreman
 
Posts: n/a
Default OK, smart guys

On Sat, 24 Jan 2004 15:30:29 GMT, PhysicsGenius
wrote:



So let's say, for the sake of argument, that I find someone to weld this
for me. First of all, where should they weld it?


Just run a fillet weld to join the pipe to a bottom cap. It's an easy
weld, wouldn't take more than a couple of minutes to do.

If they do the
outside joint, isn't aluminum going to sneak up the inside and crack it
open via expansion and contraction? Will they be able to reach inside
and weld the inside joint?


A good fillet weld will easily penetrate thru the pipe to the inside,
Even if it didn't, aluminum is considerably more ductile than steel.
Beyond that, aluminum contracts when it cools after freezing, so
even if it did get into a void it wouldn't create any stress by being
there.

Welds aren't like glue. The weld is steel just as are the joined
parts and probably thicker than the pipe. If you welded caps on both
ends of a pipe and then hydrostatically tested the resulting vessel to
destruction, the pipe would probably split before the endcap welds
failed.


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