Casting using air pressure

I'm currently thinking about and designing a simple way to cast using air
pressure. It would work similiar to some steam casting methods I have seen from
time to time. My current thinking is a simple frame to hold the necessary
parts with an air supply from one of several possible sources. The top of the
investment which would still be hot from burnout (or not) would act as the
crucible where the silver was melted. A gasketed closure then clamps onto the
top of the cylinder holding the burned out investment and air pressure applied
quickly in one motion. My question is what pressure do you think I need to
apply and how long to keep it applied. Would it be better to apply a lower
pressure (say 5 pounds) initially and then increase it? Would a lower pressure
contribute to porosity of the casting? Thanks, Mike in Arkansas

Thought this posting got lost in digital hell. Already ask this in a much
later posting.
Sounds like 15 pounds or so is a starting point. Still working on a simple
mechanical mechanism that will automatically apply the air pressure when the
handle is closed Thanks to all that replied to my later query about this. Mike
in Arkansas

Peter, I'm not entirely sure it's AOL's news server! I've noticed several
of my posts delayed by more days than I ever would have
imagined....sometimes 2, 3, 4 days! And I use an entirely different server.

"Peter W. Rowe" wrote in message
...
On Wed, 23 Jul 2003 22:15:03 -0700, in rec.crafts.jewelry
ojunk (Mike72903) wrote:

Thought this posting got lost in digital hell. Already ask this in a
much
later posting.

Mike.

I've put this reply message in the group, rather than just email, in case
it
provides relavent insight for others who's posts may seem delayed.

The posting does seem to have been unusually delayed. It reached me just
today, yet bears a posting date of the 16th, a week ago. (I'll append
the
original post with headers that I recieved to the bottom of this post, in
case
you wish to ask the AOL news admins about this...

Your second, followup post was posted to the group on the 19th. Not
really all
THAT much later, considering the delay between when you probably
originally sent
it on the 18th, and when I approved it. I can't anymore check the
original
headers for the original date on that posting, as I don't keep them that
long.

It is indeed unusual for a message to get hung up in servers that long.
You
might indeed wish to inquire of AOL's news admins just what might have
happened.
It's pretty clear in the path headers where the post got hung up.

" ngpost-m2.news.aol.com", (the AOL news server you connected to, I
think),
passed the message on the 16th, to "imo-r03.mx.aol.com" (probably an AOL
mail
server), which passed it to "chi6sosrv11.alter.net", also on the 16th. It
passed it , to the "chi6-2.relay.mail.uu.net", which sent it to the
Earthlink
mail server, and then to me, today on the 23d. The question is why the
message
got hung up on the "chi6sosrv11.alter.net" and "chi6-2.relay.mail.uu.net"
transfer. The path doesn't show a transfer between these two servers, so
I
presume it's in an internal network between the two, with one being on the
alternet domain, and the other being a uu.net relay servers. The relay is
what
knows my email address, and can then forward it to me. I presume that
what
happened is that for some reason, that particular uu.net server was down
for a
time, or otherwise misplaced or delayed the post.

Below are the headers of todays post, as I recieved it.

Hope this is of some use or interest....

Peter Rowe
moderator
rec.crafts.jewelry

Status: U
Return-Path:
Received: from chi6-2.relay.mail.uu.net ([199.171.54.99])
by killdeer (EarthLink SMTP Server) with ESMTP id 19FmXy2Gh3NZFlr0
for ; Wed, 23 Jul 2003 09:59:21 -0700 (PDT)
Received: from imo-r03.mx.aol.com by chi6sosrv11.alter.net with ESMTP
(peer crosschecked as: imo-r03.mx.aol.com [152.163.225.99])
id QQoxqa07421
for ; Wed, 16 Jul 2003 19:06:12
GMT
Received: from ngpost-m2.news.aol.com (ngpost-m2.news.aol.com
[172.20.17.108])
by imo-r03.mx.aol.com (8.8.8/8.8.8/AOL-5.0.0)
with ESMTP id PAA23369 for ;
Wed, 16 Jul 2003 15:05:50 -0400 (EDT)
To:
From: ojunk (Mike72903)
Newsgroups: rec.crafts.jewelry
Date: 16 Jul 2003 19:04:54 GMT
Organization: AOL http://www.aol.com
Subject: Casting using air pressure
Message-ID:

I'm currently thinking about and designing a simple way to cast using
air
pressure. It would work similiar to some steam casting methods I have
seen from
time to time. My current thinking is a simple frame to hold the
necessary
parts with an air supply from one of several possible sources. The top
of the
investment which would still be hot from burnout (or not) would act as
the
crucible where the silver was melted. A gasketed closure then clamps
onto the
top of the cylinder holding the burned out investment and air pressure
applied
quickly in one motion. My question is what pressure do you think I need
to
apply and how long to keep it applied. Would it be better to apply a
lower
pressure (say 5 pounds) initially and then increase it? Would a lower
pressure
contribute to porosity of the casting? Thanks, Mike in Arkansas

GhostMouse wrote:

Peter, I'm not entirely sure it's AOL's news server! I've noticed several
of my posts delayed by more days than I ever would have
imagined....sometimes 2, 3, 4 days! And I use an entirely different server.


Peter,

Do you think this could also be related to my post that did not reach you at all
afew days ago, about which I emailed you? In that case, the problem may be on
your end?

Abrasha
http://www.abrasha.com

On Thu, 24 Jul 2003 17:55:04 -0700, in rec.crafts.jewelry Abrasha
wrote:

GhostMouse wrote:

Peter, I'm not entirely sure it's AOL's news server! I've noticed several
of my posts delayed by more days than I ever would have
imagined....sometimes 2, 3, 4 days! And I use an entirely different server.


Peter,

Do you think this could also be related to my post that did not reach you at all
afew days ago, about which I emailed you? In that case, the problem may be on
your end?

Abrasha
http://www.abrasha.com

It's quite possible, and even likely, that this is the root of this sort of
problem. Note, though, that this isn't at my end, just as it's not at your end.
It's in the middle... It's not my ISP, nor yours, but apparently the relay
servers, most of which are connected either to uunet, or to one of the
university systems. The number of such relay servers varies. It used to be
there were about a dozen of them. Then at one point, someone on the moderators
listserve said it was down to four or five. Not sure where it's at now. But
whatever the number, when one goes down, or otherwise has problems, it's trouble
for the moderated groups, since unlike normal newsgroup messages, which can
reach a news server usually by more than one path, moderated posts go via email
between the original news server and the moderator. If the relay servers loose
a message, there may not be duplicate copies floating around the net to fill
in...

I'll send copies of the header block on this recent delayed message to the
moderators list serve, and see what folks there say. Some of those people are
amongst the folks who manage these underpinnings of usenet and the moderation
relays...

Peter

Oerhaps related is the fact that another NG I monitor (alt.autos.subaru)
recently began acting up - not retrieving/loading messages or requiring
multiple retires to load. Didn't used to behave that way. Seems better
today than the last week or more. Wonder why there is no news of
anything specific going on?

Carl
1 Lucky Texan


Peter W. Rowe wrote:
On Thu, 24 Jul 2003 17:55:04 -0700, in rec.crafts.jewelry Abrasha
wrote:


GhostMouse wrote:

Peter, I'm not entirely sure it's AOL's news server! I've noticed several
of my posts delayed by more days than I ever would have
imagined....sometimes 2, 3, 4 days! And I use an entirely different server.


Peter,

Do you think this could also be related to my post that did not reach you at all
afew days ago, about which I emailed you? In that case, the problem may be on
your end?

Abrasha
http://www.abrasha.com


It's quite possible, and even likely, that this is the root of this sort of
problem. Note, though, that this isn't at my end, just as it's not at your end.
It's in the middle... It's not my ISP, nor yours, but apparently the relay
servers, most of which are connected either to uunet, or to one of the
university systems. The number of such relay servers varies. It used to be
there were about a dozen of them. Then at one point, someone on the moderators
listserve said it was down to four or five. Not sure where it's at now. But
whatever the number, when one goes down, or otherwise has problems, it's trouble
for the moderated groups, since unlike normal newsgroup messages, which can
reach a news server usually by more than one path, moderated posts go via email
between the original news server and the moderator. If the relay servers loose
a message, there may not be duplicate copies floating around the net to fill
in...

I'll send copies of the header block on this recent delayed message to the
moderators list serve, and see what folks there say. Some of those people are
amongst the folks who manage these underpinnings of usenet and the moderation
relays...

Peter


--
to reply, change ( .not) to ( .net)

On Thu, 24 Jul 2003 21:32:34 -0700, in rec.crafts.jewelry Carl 1 Lucky Texan
wrote:

Oerhaps related is the fact that another NG I monitor (alt.autos.subaru)
recently began acting up - not retrieving/loading messages or requiring
multiple retires to load. Didn't used to behave that way. Seems better
today than the last week or more. Wonder why there is no news of
anything specific going on?

Carl
1 Lucky Texan

Anything related to the way you actually read or download messages on the
groups, both moderated or not, will be related only to issues at your own ISP.
Unless you read the groups at some remote site, such as google, newsgroups are
generally accessed through the local news server at one's own ISP. When you
read the groups, generally your never actually connecting to the internet,
except as needed for local connections within your ISP's setup from one division
of your ISP to another, such as from the modem you call into, to their actual
servers. Usually, these are dedicated connetions however. This would be why
there's "no news". it isn't global to the net, unless of course there's
something like some sort of common virus or worm or something that's attacking
news servers (haven't heard anything of the sort).

The problem this thread discussed is a situation unique only to moderated
groups.

In unmoderated groups, you send a message to the group, and it can appear
immediately in your listing of messages on the group, because you're seeing it
appear essentially on the same server you sent it to. Other subscribers at your
ISP will also see it then. Once your news server accepts it, it then sends it
out over the net to all the other news servers, which may get it quickly, or
not, but each is different. Any delays in this, however, are not apparent to
you, unless you access some other news server on another ISP. One way to do
this is to send a message, see it appear on your ISP's news server, and then see
how long it takes to appear on Google, or one of the other "pay for service"
news services one can subscribe to. Most folks don't do this.

With moderated groups, anything you send to the group is accepted by your news
server, but instead of showing it on it's own listings and then broadcasting it
to the news feeds, it shunts it to an email server, which sends it to one of the
several moderation relay servers. These then forward the messages to the
moderators, who approve them and post the messages to their OWN ISP's news
server. That server then lists it normally and sends it on the newsfeeds,
where, eventually, your own news server will get it and show it. The speed with
which these transfers take place can vary a lot, from a few seconds or minutes,
to several hours, if the servers are very busy. Usually, it's pretty quick.

Delays in the moderation relay servers are quite unusual, however, since there
are only about 500 moderated groups in usenet, and most are fairly low volume,
thus the relays shouldn't get overwhelmed. Certain types of spam or denail of
service attacks can do it, but then it tends to be system wide, rather than just
selected messages being delayed.

My guess is that one of the several relays is having internal problems of some
sort. Hopefully, it will get sorted out...

Peter Rowe