Need a 9" dia hole in a 20# sheet metal
surround of a boiler.

The hole must be neat and cut in situ.

Is there a gadget constructed like a compass
that when rotated often enough will cut such
a hole?

Rather like the typical rotating glass cutter
used for cutting large holes in plate glass.

Please help, Frank

Peter Jason wrote:

Need a 9" dia hole in a 20# sheet metal
surround of a boiler.

The hole must be neat and cut in situ.

Is there a gadget constructed like a compass
that when rotated often enough will cut such
a hole?

Rather like the typical rotating glass cutter
used for cutting large holes in plate glass.

Sure. It's a circle cutting attachment for a plasma cutter.

GWE

A nibbler will do the job very nicely. Followup cleaning with a file can
make a hole that just belongs in the piece of sheet metal.

--
Why do penguins walk so far to get to their nesting grounds?

"Peter Jason" wrote in message
...
Need a 9" dia hole in a 20# sheet metal
surround of a boiler.

The hole must be neat and cut in situ.

Is there a gadget constructed like a compass
that when rotated often enough will cut such
a hole?

Rather like the typical rotating glass cutter
used for cutting large holes in plate glass.

Please help, Frank


Careful work taking small bites with a pair of left or right cutting snips
will make a good hole of this size.
Don Young

In situ is so complex - and in this case it might be best to
just say while it is mounted on top of the boiler or in a water deep
basement or in the .....

For the case naturally - you could use trammel points or a Plasma / gas torch
circle cutter but put a carbide scribe and cut a hole like glass but all the
way through.

I surmise you have a boiler with a cover that has an 8" hole and you want to
put on a 9" header pipe or some such.

Otherwise it would be easy for most sheet metal shops in town.

Martin

Martin Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
NRA LOH & Endowment Member
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member


Peter Jason wrote:
Need a 9" dia hole in a 20# sheet metal
surround of a boiler.

The hole must be neat and cut in situ.

Is there a gadget constructed like a compass
that when rotated often enough will cut such
a hole?

Rather like the typical rotating glass cutter
used for cutting large holes in plate glass.

Please help, Frank



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On Fri, 07 Apr 2006 09:27:48 +1000, Peter Jason wrote:

Need a 9" dia hole in a 20# sheet metal
surround of a boiler.

The hole must be neat and cut in situ.


A makeshift trammel bar of wood (1 x 2" for ex.) with a tool steel cutter
should do fine with that thin guage--pivoting on a small bolt.

Or a saber saw, with a circle-cutting guide and a toothless blade, the
kind with carbide grit available at most hardware stores.

Ken Grunke


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Thanks for all replies, I found the following
after much looking:
http://www.mk-diamond-saws.com/image...tter_small.jpg

and

http://ignitiontools.com/auctionpic/...E-CUTTER-1.jpg

and

http://www.trilug.org/~chilcote/imag...e-cutter-s.jpg

and

http://zenstoves.net/Supplies/CircleHoleCutter.jpg

Regards, Frank



"Ken Grunke"
wrote in message
news
On Fri, 07 Apr 2006 09:27:48 +1000, Peter
Jason wrote:

Need a 9" dia hole in a 20# sheet metal
surround of a boiler.

The hole must be neat and cut in situ.


A makeshift trammel bar of wood (1 x 2" for
ex.) with a tool steel cutter
should do fine with that thin
guage--pivoting on a small bolt.

Or a saber saw, with a circle-cutting guide
and a toothless blade, the
kind with carbide grit available at most
hardware stores.

Ken Grunke


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News==----
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Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms -
Total Privacy via Encryption =----

Peter Jason wrote:
...
http://www.mk-diamond-saws.com/image...tter_small.jpg
http://ignitiontools.com/auctionpic/...E-CUTTER-1.jpg
http://www.trilug.org/~chilcote/imag...e-cutter-s.jpg
http://zenstoves.net/Supplies/CircleHoleCutter.jpg

All of these tools are meant to be used in a drill press, for the
stability. I have used a circle cutter in a hand drill, but it was a
much smaller hole (4" diam) and it was tricky. If you do it, be very,
*very* careful. Use the very slowest speed that you can and keep a very
tight grip on the drill. The problem is that the bit will grab and
bind. Depending upon how flexible the boiler surround is, it may very
well be impossible with a hand drill.

Bob

My boiler sides and top come off fairly easily- weil-mclane gold oil
boiler.

Dave

All of those will be a disaster when used on thin material and large
diameter. They are normally used in a drill press and the work securely
clamped down. When used with a portable dirll the cutting edges will dig
in and tear the metal or flip the portable drill (and user).

There is a circle cutter used by sheet metal installers that has a
tramel point on one end, and a pilot bushing on the other. To use, mark
the center, install guide, use a spiral cutter bit in an electric drill.
Don't have a link to it.

Peter Jason wrote:
Thanks for all replies, I found the following
after much looking:
http://www.mk-diamond-saws.com/image...tter_small.jpg

and

http://ignitiontools.com/auctionpic/...E-CUTTER-1.jpg

and

http://www.trilug.org/~chilcote/imag...e-cutter-s.jpg

and

http://zenstoves.net/Supplies/CircleHoleCutter.jpg

Regards, Frank



"Ken Grunke"
wrote in message
news
On Fri, 07 Apr 2006 09:27:48 +1000, Peter
Jason wrote:


Need a 9" dia hole in a 20# sheet metal
surround of a boiler.

The hole must be neat and cut in situ.


A makeshift trammel bar of wood (1 x 2" for
ex.) with a tool steel cutter
should do fine with that thin
guage--pivoting on a small bolt.

Or a saber saw, with a circle-cutting guide
and a toothless blade, the
kind with carbide grit available at most
hardware stores.

Ken Grunke


----== Posted via Newsfeeds.Com -
Unlimited-Unrestricted-Secure Usenet
News==----
http://www.newsfeeds.com The #1 Newsgroup
Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms -
Total Privacy via Encryption =----

My problem is to fix the mess left by a
long-departed builder who installed a boiler
half above a roof and half below it. Thus
the service panel is sealed into the roof and
now I have to cut another access to service
the gas regulator.



wrote in message
oups.com...
My boiler sides and top come off fairly
easily- weil-mclane gold oil
boiler.

Dave

This tool is made to do exactly what you are doing:

http://malco.malcoproducts.com/products/shear/hc1.asp

______________________________
Keep the whole world singing . . . .
DanG (remove the sevens)




"Peter Jason" wrote in message
...
Need a 9" dia hole in a 20# sheet metal
surround of a boiler.

The hole must be neat and cut in situ.

Is there a gadget constructed like a compass
that when rotated often enough will cut such
a hole?

Rather like the typical rotating glass cutter
used for cutting large holes in plate glass.

Please help, Frank

Thank you; I will try to get hold of one.


"DanG" wrote in message
news:F1EZf.41$EA3.4@dukeread10...
This tool is made to do exactly what you
are doing:

http://malco.malcoproducts.com/products/shear/hc1.asp

______________________________
Keep the whole world singing . . . .
DanG (remove the sevens)




"Peter Jason" wrote in
message
...
Need a 9" dia hole in a 20# sheet metal
surround of a boiler.

The hole must be neat and cut in situ.

Is there a gadget constructed like a
compass
that when rotated often enough will cut
such
a hole?

Rather like the typical rotating glass
cutter
used for cutting large holes in plate
glass.

Please help, Frank

On Sat, 8 Apr 2006 09:16:28 +1000, "Peter Jason"
wrote:

My problem is to fix the mess left by a
long-departed builder who installed a boiler
half above a roof and half below it. Thus
the service panel is sealed into the roof and
now I have to cut another access to service
the gas regulator.

Holy Stupid Designs, Batman!...

Forget cutting an access hole through the sheetmetal to fix the
boiler long term, because then you'll have to deal with rain leaks...
Sounds more like it is time to rework the boiler and/or the roof so
you have proper service access.

Stick some pictures of what you've got there now (and how you get
access to it now) in the drop-box, and people can make educated
suggestions on a proper course of action that will look good, be
fairly easy to build, and won't break the bank. Include distance and
roofline silhouette shots so people can get the 'theme' of the
architecture.

I have several ideas on building a little roof or housing over the
unit, but random guessing wastes time without seeing the start and end
points.

-- Bruce --

--
Bruce L. Bergman, Woodland Hills (Los Angeles) CA - Desktop
Electrician for Westend Electric - CA726700
5737 Kanan Rd. #359, Agoura CA 91301 (818) 889-9545
Spamtrapped address: Remove the python and the invalid, and use a net.

Why not. I'll post some photos within the
next few days.


"Bruce L. Bergman"
wrote in
message
...
On Sat, 8 Apr 2006 09:16:28 +1000, "Peter
Jason"
wrote:

My problem is to fix the mess left by a
long-departed builder who installed a
boiler
half above a roof and half below it. Thus
the service panel is sealed into the roof
and
now I have to cut another access to service
the gas regulator.

Holy Stupid Designs, Batman!...

Forget cutting an access hole through the
sheetmetal to fix the
boiler long term, because then you'll have
to deal with rain leaks...
Sounds more like it is time to rework the
boiler and/or the roof so
you have proper service access.

Stick some pictures of what you've got
there now (and how you get
access to it now) in the drop-box, and
people can make educated
suggestions on a proper course of action
that will look good, be
fairly easy to build, and won't break the
bank. Include distance and
roofline silhouette shots so people can get
the 'theme' of the
architecture.

I have several ideas on building a little
roof or housing over the
unit, but random guessing wastes time
without seeing the start and end
points.

-- Bruce --

--
Bruce L. Bergman, Woodland Hills (Los
Angeles) CA - Desktop
Electrician for Westend Electric - CA726700
5737 Kanan Rd. #359, Agoura CA 91301 (818)
889-9545
Spamtrapped address: Remove the python and
the invalid, and use a net.

On Sun, 9 Apr 2006 09:39:45 +1000, "Peter Jason"
wrote:

Why not. I'll post some photos within the
next few days.

Start a new thread when you do, and announce where the pictures are.

I deal with several condo buildings where they just have a Raypak
natural gas fired domestic hot water boiler and a storage tank just
sitting out there exposed on the building roof. All you need to
protect from rain are the pump motors.

If nothing else, I've got to see why they would think they need to
seal the unit half inside the roof - they are designed for outdoor
installation.

Unless some doofus couldn't figure out how to properly fix the
section of the roof the boiler is sitting on, and found that sealing
the whole area stopped the leak...

(For something like that, you erect an A-frame, lift the boiler an
inch or two, have the roofers redo the roofing around the pedestal
it's sitting on, and then you slide a new sheetmetal drip pan under
the boiler before you drop it back down. Oh, and drop it on rubber
waffle pads so it doesn't wiggle a hole in the sheetmetal cap.)

-- Bruce --

--
Bruce L. Bergman, Woodland Hills (Los Angeles) CA - Desktop
Electrician for Westend Electric - CA726700
5737 Kanan Rd. #359, Agoura CA 91301 (818) 889-9545
Spamtrapped address: Remove the python and the invalid, and use a net.

Bob Engelhardt wrote:
Peter Jason wrote:
...
http://www.mk-diamond-saws.com/image...tter_small.jpg
http://ignitiontools.com/auctionpic/...E-CUTTER-1.jpg
http://www.trilug.org/~chilcote/imag...e-cutter-s.jpg
http://zenstoves.net/Supplies/CircleHoleCutter.jpg

All of these tools are meant to be used in a drill press, for the
stability. I have used a circle cutter in a hand drill, but it was a
much smaller hole (4" diam) and it was tricky. If you do it, be very,
*very* careful. Use the very slowest speed that you can and keep a very
tight grip on the drill. The problem is that the bit will grab and
bind. Depending upon how flexible the boiler surround is, it may very
well be impossible with a hand drill.

Bob

I have some hole cutters simular to the ones in those links.

Are there any "trammel-type" cutters that can be used with a lathe?(MT2
or MT3).

(The holes I have to make in sheet metal are up to three inches in
diameter).

Thanks.

Darren Harris
Staten Island, New York.

According to Peter Jason :
"Bruce L. Bergman"
wrote in
message ...
On Sun, 9 Apr 2006 09:39:45 +1000, "Peter
Jason"
wrote:

Why not. I'll post some photos within the
next few days.

Start a new thread when you do, and
announce where the pictures are.

I enclose the pictures here, and the hole
will be cut at the red "x".

Note that he said "announce where the pictures are", which
implied that they should *not* be posted to the newsgroup. Just because
it is *technically* possible does not mean that it is acceptable
behavior.

rec.crafts.metalworking is a text-only newsgroup, not a binary
one, so binaries (including images and sound files) are not acceptable
use. Binary newsgroups may be recognized by the word "binaries" present
in the newsgroup name.

You were supposed to upload the images to some web site like the
dropbox (http://www.metalworking.com -- visit there to read how to do
this), and then post the resulting URL here pointing to where the images
are.

There is an above roof & below roof picture,
and you will see how the builder has cemented
the outer casing to the roof itself.

Any comments would be most welcome.

You have my comments on the presence of the images themselves
here. I'll leave it to others to comment on the questions associated
with the metal cutting asked here.

Good Luck,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

I found one, and have ordered it.
Thanks again.

"Peter Jason" wrote in
message
...
Thank you; I will try to get hold of one.


"DanG" wrote in
message news:F1EZf.41$EA3.4@dukeread10...
This tool is made to do exactly what you
are doing:

http://malco.malcoproducts.com/products/shear/hc1.asp

______________________________
Keep the whole world singing . . . .
DanG (remove the sevens)




"Peter Jason" wrote in
message
...
Need a 9" dia hole in a 20# sheet metal
surround of a boiler.

The hole must be neat and cut in situ.

Is there a gadget constructed like a
compass
that when rotated often enough will cut
such
a hole?

Rather like the typical rotating glass
cutter
used for cutting large holes in plate
glass.

Please help, Frank

(DoN. Nichols) writes:

Note that he said "announce where the pictures are", which
implied that they should *not* be posted to the newsgroup. Just
because it is *technically* possible does not mean that it is
acceptable behavior.

It's not just a matter of etiquette-- many news servers automatically
delete binary postings in non-binary newsgroups, so a lot of us don't
even see them.

The binary newsgroups are kept separate because they take up a *huge*
amount of bandwidth and disk space, compared to the text newsgroups, and
they put a big strain on the servers (a picture is a lot more data than a
thousand words).