On Sun, 13 Dec 2015 20:03:38 -0600, "Terry Coombs"
wrote:

The day I picked up the stove grates I also picked up a small "fire pot"
that was cracked/broken . The break is across a 2" horizontal then about 1"
vertical - kind of like an angle iron but not at 90° . I attempted a repair
on it yesterday , beginning with a tack at the corner and one at the
horizontal edge . That part went well ... but when I tried to fill in
between the two tacks it keeps cracking . I have a hammer handy and begin
peening before my helmet clears ... I have not preheated this piece because
of the size and awkwardness, and I think that's what's killing me . The TIG
heat is so localized that the nearby mass of iron is acting as a chill and
sucking the heat out so fast I can't peen fast enough to stop the cracking .
I can't heat the whole part , but I can heat the repair area . The part is
like an oval sleeve , with nothing to restrict expansion in any direction so
I think I can safely heat just that area . The question is how hot and will
this help keep it from cracking ? I tried some CI strips first , then the
Invar 42 , same results with both fillers ./
Are you anywhere near a pottery supply company? If so, get some
ceramic wool and wrap the piece after heating. As to how hot in my
experience if I heat cast iron to about 700 degrees it won't crack. I
have had the best luck heating to a dull red heat when observed in low
light, wrapping in ceramic wool, and welding. It's a pain because
everything is so hot but on the other hand no peening is required and
no cracking is happening. I have used this method with brazing rod,
aluminum bronze rod, stainless steel rod, and nickel alloy rods.
Eric

wrote:
On Sun, 13 Dec 2015 20:03:38 -0600, "Terry Coombs"
wrote:

The day I picked up the stove grates I also picked up a small "fire
pot" that was cracked/broken . The break is across a 2" horizontal
then about 1" vertical - kind of like an angle iron but not at 90° .
I attempted a repair on it yesterday , beginning with a tack at the
corner and one at the horizontal edge . That part went well ... but
when I tried to fill in between the two tacks it keeps cracking . I
have a hammer handy and begin peening before my helmet clears ... I
have not preheated this piece because of the size and awkwardness,
and I think that's what's killing me . The TIG heat is so localized
that the nearby mass of iron is acting as a chill and sucking the
heat out so fast I can't peen fast enough to stop the cracking . I
can't heat the whole part , but I can heat the repair area . The
part is like an oval sleeve , with nothing to restrict expansion in
any direction so I think I can safely heat just that area . The
question is how hot and will this help keep it from cracking ? I
tried some CI strips first , then the Invar 42 , same results with
both fillers ./
Are you anywhere near a pottery supply company? If so, get some
ceramic wool and wrap the piece after heating. As to how hot in my
experience if I heat cast iron to about 700 degrees it won't crack. I
have had the best luck heating to a dull red heat when observed in low
light, wrapping in ceramic wool, and welding. It's a pain because
everything is so hot but on the other hand no peening is required and
no cracking is happening. I have used this method with brazing rod,
aluminum bronze rod, stainless steel rod, and nickel alloy rods.
Eric

I don't have a pottery supply near , but I do have a large pile of
fiberglass batts . You think they'll work at the temps you use ? The grates
aren't so awkward in shape , I plan to build an enclosure with firebricks
and preheat with my foundry burner . Heat 'em both up and let one soak while
I weld on the other , swap as they cool .

--
Snag

On Mon, 14 Dec 2015 18:43:35 -0600, "Terry Coombs"
wrote:

wrote:
On Sun, 13 Dec 2015 20:03:38 -0600, "Terry Coombs"
wrote:

The day I picked up the stove grates I also picked up a small "fire
pot" that was cracked/broken . The break is across a 2" horizontal
then about 1" vertical - kind of like an angle iron but not at 90° .
I attempted a repair on it yesterday , beginning with a tack at the
corner and one at the horizontal edge . That part went well ... but
when I tried to fill in between the two tacks it keeps cracking . I
have a hammer handy and begin peening before my helmet clears ... I
have not preheated this piece because of the size and awkwardness,
and I think that's what's killing me . The TIG heat is so localized
that the nearby mass of iron is acting as a chill and sucking the
heat out so fast I can't peen fast enough to stop the cracking . I
can't heat the whole part , but I can heat the repair area . The
part is like an oval sleeve , with nothing to restrict expansion in
any direction so I think I can safely heat just that area . The
question is how hot and will this help keep it from cracking ? I
tried some CI strips first , then the Invar 42 , same results with
both fillers ./
Are you anywhere near a pottery supply company? If so, get some
ceramic wool and wrap the piece after heating. As to how hot in my
experience if I heat cast iron to about 700 degrees it won't crack. I
have had the best luck heating to a dull red heat when observed in low
light, wrapping in ceramic wool, and welding. It's a pain because
everything is so hot but on the other hand no peening is required and
no cracking is happening. I have used this method with brazing rod,
aluminum bronze rod, stainless steel rod, and nickel alloy rods.
Eric

I don't have a pottery supply near , but I do have a large pile of
fiberglass batts . You think they'll work at the temps you use ? The grates
aren't so awkward in shape , I plan to build an enclosure with firebricks
and preheat with my foundry burner . Heat 'em both up and let one soak while
I weld on the other , swap as they cool .
I don't know about the fiberglass batts because I think they use some
sort of glue to hold the fibers together. Tear a small chunk off and
point a torch at it to see if it burns. Not too close because the tiny
glass fibers may burn while in the torch flame. Your enclosure idea
is a good one. Lay the grate on some more fire brick while welding so
that it doesn't lose heat through conduction. You know, I bet the
fiberglass would be fine if it was just used to cover the part while
it was being welded. Try it. It just occurred to me that a fireplace
shop may also have ceramic woll.
Eric

wrote:
On Mon, 14 Dec 2015 18:43:35 -0600, "Terry Coombs"
wrote:

wrote:
On Sun, 13 Dec 2015 20:03:38 -0600, "Terry Coombs"
wrote:

The day I picked up the stove grates I also picked up a small
"fire pot" that was cracked/broken . The break is across a 2"
horizontal then about 1" vertical - kind of like an angle iron but
not at 90° . I attempted a repair on it yesterday , beginning with
a tack at the corner and one at the horizontal edge . That part
went well ... but when I tried to fill in between the two tacks it
keeps cracking . I have a hammer handy and begin peening before my
helmet clears ... I have not preheated this piece because of the
size and awkwardness, and I think that's what's killing me . The
TIG heat is so localized that the nearby mass of iron is acting as
a chill and sucking the heat out so fast I can't peen fast enough
to stop the cracking . I can't heat the whole part , but I can
heat the repair area . The part is like an oval sleeve , with
nothing to restrict expansion in any direction so I think I can
safely heat just that area . The question is how hot and will this
help keep it from cracking ? I tried some CI strips first , then
the Invar 42 , same results with both fillers ./
Are you anywhere near a pottery supply company? If so, get some
ceramic wool and wrap the piece after heating. As to how hot in my
experience if I heat cast iron to about 700 degrees it won't crack.
I have had the best luck heating to a dull red heat when observed
in low light, wrapping in ceramic wool, and welding. It's a pain
because everything is so hot but on the other hand no peening is
required and no cracking is happening. I have used this method with
brazing rod, aluminum bronze rod, stainless steel rod, and nickel
alloy rods.
Eric

I don't have a pottery supply near , but I do have a large pile of
fiberglass batts . You think they'll work at the temps you use ? The
grates aren't so awkward in shape , I plan to build an enclosure
with firebricks and preheat with my foundry burner . Heat 'em both
up and let one soak while I weld on the other , swap as they cool .
I don't know about the fiberglass batts because I think they use some
sort of glue to hold the fibers together. Tear a small chunk off and
point a torch at it to see if it burns. Not too close because the tiny
glass fibers may burn while in the torch flame. Your enclosure idea
is a good one. Lay the grate on some more fire brick while welding so
that it doesn't lose heat through conduction. You know, I bet the
fiberglass would be fine if it was just used to cover the part while
it was being welded. Try it. It just occurred to me that a fireplace
shop may also have ceramic woll.
Eric

Heh , we don't have one of those too . This is a very small (5,000) very
isolated town - the nearest freeway is a hundred miles away more or less .
Those 'glass batts were salvaged fom a tearout , cost me the labor to load
'em up .
Today I'm working on toy boxes for my 2 youngest grand daughters .
Tomorrow I'll be setting up for the CI job , get it outta the way so I can
go back to laying cement block yecchhh for our new cellar .
--
Snag

Terry Coombs wrote:


I don't have a pottery supply near , but I do have a large pile of
fiberglass batts . You think they'll work at the temps you use ? The
grates aren't so awkward in shape , I plan to build an enclosure with
firebricks and preheat with my foundry burner . Heat 'em both up and let
one soak while I weld on the other , swap as they cool .

No, you can melt fiberglass on a kitchen stove. I don't know what the glass
type is, but really low melting point.

Jon

Jon Elson wrote:
Terry Coombs wrote:


I don't have a pottery supply near , but I do have a large pile of
fiberglass batts . You think they'll work at the temps you use ? The
grates aren't so awkward in shape , I plan to build an enclosure with
firebricks and preheat with my foundry burner . Heat 'em both up and
let one soak while I weld on the other , swap as they cool .

No, you can melt fiberglass on a kitchen stove. I don't know what
the glass type is, but really low melting point.

Jon

THanks , looks like I'll be inventorying the fire bricks . I've got enough ,
just gotta dig 'em out of storage .

--
Snag

On Tue, 15 Dec 2015 14:48:33 -0600, "Terry Coombs"
wrote:

Jon Elson wrote:
Terry Coombs wrote:


I don't have a pottery supply near , but I do have a large pile of
fiberglass batts . You think they'll work at the temps you use ? The
grates aren't so awkward in shape , I plan to build an enclosure with
firebricks and preheat with my foundry burner . Heat 'em both up and
let one soak while I weld on the other , swap as they cool .

No, you can melt fiberglass on a kitchen stove. I don't know what
the glass type is, but really low melting point.

Jon

THanks , looks like I'll be inventorying the fire bricks . I've got enough ,
just gotta dig 'em out of storage .

I guess you know to heat and dry them slowly if they got damp. I keep
mine in a big plastic bag (3 mil) made for collecting trash on
construction sites. They can crack, and even explode, if you heat them
when they're really damp or wet.

Glass wool melts at around 1,000 deg. F. If they use Johns Manville
Mineral Wool for insulation in your area, that melts at around 2,000
F. Other kinds of "rock wool" and "mineral wool" vary all over the
map. The old stuff was made from steel mill slag, but they make it
from a variety of things today.

You shouldn't heat your iron above 1,200 F. It goes hot-short at
around 1,400 F or just over, and it will crack if you look at it
cross-eyed at that temperature. Lincoln Electric says to pre-heat in
the range of 500 - 1,200 deg. F.

http://www.lincolnelectric.com/en-us...on-detail.aspx

--
Ed Huntress

On 15/12/15 20:48, Terry Coombs wrote:
Jon Elson wrote:
Terry Coombs wrote:


I don't have a pottery supply near , but I do have a large pile of
fiberglass batts . You think they'll work at the temps you use ? The
grates aren't so awkward in shape , I plan to build an enclosure with
firebricks and preheat with my foundry burner . Heat 'em both up and
let one soak while I weld on the other , swap as they cool .

No, you can melt fiberglass on a kitchen stove. I don't know what
the glass type is, but really low melting point.

Jon
THanks , looks like I'll be inventorying the fire bricks . I've got enough ,
just gotta dig 'em out of storage .

The fact it can be melted in a kitchen stove flame isn't really a good
indication of its service temperature as it was exposed to the naked
flame, it may well be fine to insulate your piece if placed on it after
heating rather than exposing it to direct flame, you may just get some
binder burning off. I don't know about fibreglass insulation but some
refractory fibre material I use on occasions use starch as a binder, a
bit whiffy when burning out but fairly harmless. I work with glass as an
amateur glass blower and normal annealing temperature for soda lime
glass is around 500C and fibreglass insulation is made from a mix of new
and recycled soda lime glass. This table may give you some idea
http://www.engineeringtoolbox.com/in...res-d_922.html .
Regarding melting fibreglass on a kitchen stove I've melted or badly
damaged woven silica cloth with a propane torch and that has a far
higher melting point than glass, concentrated heat on fine fibres does
the damage.

On 15/12/15 21:03, Ed Huntress wrote:
On Tue, 15 Dec 2015 14:48:33 -0600, "Terry Coombs"
wrote:

Jon Elson wrote:
Terry Coombs wrote:


I don't have a pottery supply near , but I do have a large pile of
fiberglass batts . You think they'll work at the temps you use ? The
grates aren't so awkward in shape , I plan to build an enclosure with
firebricks and preheat with my foundry burner . Heat 'em both up and
let one soak while I weld on the other , swap as they cool .

No, you can melt fiberglass on a kitchen stove. I don't know what
the glass type is, but really low melting point.

Jon
THanks , looks like I'll be inventorying the fire bricks . I've got enough ,
just gotta dig 'em out of storage .
I guess you know to heat and dry them slowly if they got damp. I keep
mine in a big plastic bag (3 mil) made for collecting trash on
construction sites. They can crack, and even explode, if you heat them
when they're really damp or wet.

Glass wool melts at around 1,000 deg. F. If they use Johns Manville
Mineral Wool for insulation in your area, that melts at around 2,000
F. Other kinds of "rock wool" and "mineral wool" vary all over the
map. The old stuff was made from steel mill slag, but they make it
from a variety of things today.

You shouldn't heat your iron above 1,200 F. It goes hot-short at
around 1,400 F or just over, and it will crack if you look at it
cross-eyed at that temperature. Lincoln Electric says to pre-heat in
the range of 500 - 1,200 deg. F.

http://www.lincolnelectric.com/en-us...on-detail.aspx

Good point on the fire brick if dense fire brick but if insulating fire
brick it's so porous I can't see it being an issue as it would just
vent steam when heated. If I need to make a temporary hearth I have
quite a few 2300F and 2600F classification temperature IFB.

David Billington wrote:
On 15/12/15 21:03, Ed Huntress wrote:
On Tue, 15 Dec 2015 14:48:33 -0600, "Terry Coombs"
wrote:

Jon Elson wrote:
Terry Coombs wrote:


I don't have a pottery supply near , but I do have a large
pile of fiberglass batts . You think they'll work at the temps
you use ? The grates aren't so awkward in shape , I plan to build
an enclosure with firebricks and preheat with my foundry burner .
Heat 'em both up and let one soak while I weld on the other ,
swap as they cool .
No, you can melt fiberglass on a kitchen stove. I don't know what
the glass type is, but really low melting point.

Jon
THanks , looks like I'll be inventorying the fire bricks . I've got
enough , just gotta dig 'em out of storage .
I guess you know to heat and dry them slowly if they got damp. I keep
mine in a big plastic bag (3 mil) made for collecting trash on
construction sites. They can crack, and even explode, if you heat
them when they're really damp or wet.

These are the porous brick , useta reside in a pottery kiln until Agnes
overheated it and melted the trays that carried the heater elements . Ugly .


Glass wool melts at around 1,000 deg. F. If they use Johns Manville
Mineral Wool for insulation in your area, that melts at around 2,000
F. Other kinds of "rock wool" and "mineral wool" vary all over the
map. The old stuff was made from steel mill slag, but they make it
from a variety of things today.

You shouldn't heat your iron above 1,200 F. It goes hot-short at
around 1,400 F or just over, and it will crack if you look at it
cross-eyed at that temperature. Lincoln Electric says to pre-heat in
the range of 500 - 1,200 deg. F.

My target temp was around 600° F .



http://www.lincolnelectric.com/en-us...on-detail.aspx

Good point on the fire brick if dense fire brick but if insulating
fire brick it's so porous I can't see it being an issue as it would
just vent steam when heated. If I need to make a temporary hearth I
have quite a few 2300F and 2600F classification temperature IFB.

I have the porous bricks and I'm not sure of the rating but I know Agnes
fired up to 2600° F . Got a nice pile of the bricks plus the top of a
smaller kiln and the top and bottom of a big one here - and the rest of the
big one still down in Memphis . I've been planning on building a forge and a
smaller foundry furnace for bronze/brass with the material so I guess I'll
have to be careful how I cut it (if I cut it) .
--
Snag

On Tue, 15 Dec 2015 13:24:16 -0600, "Terry Coombs"
wrote:

wrote:
On Mon, 14 Dec 2015 18:43:35 -0600, "Terry Coombs"
wrote:

wrote:
On Sun, 13 Dec 2015 20:03:38 -0600, "Terry Coombs"
wrote:

The day I picked up the stove grates I also picked up a small
"fire pot" that was cracked/broken . The break is across a 2"
horizontal then about 1" vertical - kind of like an angle iron but
not at 90° . I attempted a repair on it yesterday , beginning with
a tack at the corner and one at the horizontal edge . That part
went well ... but when I tried to fill in between the two tacks it
keeps cracking . I have a hammer handy and begin peening before my
helmet clears ... I have not preheated this piece because of the
size and awkwardness, and I think that's what's killing me . The
TIG heat is so localized that the nearby mass of iron is acting as
a chill and sucking the heat out so fast I can't peen fast enough
to stop the cracking . I can't heat the whole part , but I can
heat the repair area . The part is like an oval sleeve , with
nothing to restrict expansion in any direction so I think I can
safely heat just that area . The question is how hot and will this
help keep it from cracking ? I tried some CI strips first , then
the Invar 42 , same results with both fillers ./
Are you anywhere near a pottery supply company? If so, get some
ceramic wool and wrap the piece after heating. As to how hot in my
experience if I heat cast iron to about 700 degrees it won't crack.
I have had the best luck heating to a dull red heat when observed
in low light, wrapping in ceramic wool, and welding. It's a pain
because everything is so hot but on the other hand no peening is
required and no cracking is happening. I have used this method with
brazing rod, aluminum bronze rod, stainless steel rod, and nickel
alloy rods.
Eric

I don't have a pottery supply near , but I do have a large pile of
fiberglass batts . You think they'll work at the temps you use ? The
grates aren't so awkward in shape , I plan to build an enclosure
with firebricks and preheat with my foundry burner . Heat 'em both
up and let one soak while I weld on the other , swap as they cool .
I don't know about the fiberglass batts because I think they use some
sort of glue to hold the fibers together. Tear a small chunk off and
point a torch at it to see if it burns. Not too close because the tiny
glass fibers may burn while in the torch flame. Your enclosure idea
is a good one. Lay the grate on some more fire brick while welding so
that it doesn't lose heat through conduction. You know, I bet the
fiberglass would be fine if it was just used to cover the part while
it was being welded. Try it. It just occurred to me that a fireplace
shop may also have ceramic woll.
Eric

Heh , we don't have one of those too . This is a very small (5,000) very
isolated town - the nearest freeway is a hundred miles away more or less .
Those 'glass batts were salvaged fom a tearout , cost me the labor to load
'em up .
Today I'm working on toy boxes for my 2 youngest grand daughters .
Tomorrow I'll be setting up for the CI job , get it outta the way so I can
go back to laying cement block yecchhh for our new cellar .
Greetings Terry,
The ceramic wool I use is available from Seattle Pottery Supply for
$1.75 per square foot. This link may get you to the right page:
http://www.seattlepotterysupply.com/...gory_Code=CFIP
I live on an island north of Seattle and so I understand what it is
like to have everything you need or want far away. If you are going to
do more than just a few pre heat/post heat type repairs in the next
few years it may be wise to order a few square feet of the ceramic
wool. The stuff is great for wrapping stuff that needs to cool down
slowly. It is pretty light so shipping should be pretty cheap. And I'm
sure there is a supplier closer to you than Seattle.
Cheers,
Eric

On 16/12/15 17:27, wrote:
On Tue, 15 Dec 2015 13:24:16 -0600, "Terry Coombs"
wrote:

wrote:
On Mon, 14 Dec 2015 18:43:35 -0600, "Terry Coombs"
wrote:

wrote:
On Sun, 13 Dec 2015 20:03:38 -0600, "Terry Coombs"
wrote:

The day I picked up the stove grates I also picked up a small
"fire pot" that was cracked/broken . The break is across a 2"
horizontal then about 1" vertical - kind of like an angle iron but
not at 90° . I attempted a repair on it yesterday , beginning with
a tack at the corner and one at the horizontal edge . That part
went well ... but when I tried to fill in between the two tacks it
keeps cracking . I have a hammer handy and begin peening before my
helmet clears ... I have not preheated this piece because of the
size and awkwardness, and I think that's what's killing me . The
TIG heat is so localized that the nearby mass of iron is acting as
a chill and sucking the heat out so fast I can't peen fast enough
to stop the cracking . I can't heat the whole part , but I can
heat the repair area . The part is like an oval sleeve , with
nothing to restrict expansion in any direction so I think I can
safely heat just that area . The question is how hot and will this
help keep it from cracking ? I tried some CI strips first , then
the Invar 42 , same results with both fillers ./
Are you anywhere near a pottery supply company? If so, get some
ceramic wool and wrap the piece after heating. As to how hot in my
experience if I heat cast iron to about 700 degrees it won't crack.
I have had the best luck heating to a dull red heat when observed
in low light, wrapping in ceramic wool, and welding. It's a pain
because everything is so hot but on the other hand no peening is
required and no cracking is happening. I have used this method with
brazing rod, aluminum bronze rod, stainless steel rod, and nickel
alloy rods.
Eric
I don't have a pottery supply near , but I do have a large pile of
fiberglass batts . You think they'll work at the temps you use ? The
grates aren't so awkward in shape , I plan to build an enclosure
with firebricks and preheat with my foundry burner . Heat 'em both
up and let one soak while I weld on the other , swap as they cool .
I don't know about the fiberglass batts because I think they use some
sort of glue to hold the fibers together. Tear a small chunk off and
point a torch at it to see if it burns. Not too close because the tiny
glass fibers may burn while in the torch flame. Your enclosure idea
is a good one. Lay the grate on some more fire brick while welding so
that it doesn't lose heat through conduction. You know, I bet the
fiberglass would be fine if it was just used to cover the part while
it was being welded. Try it. It just occurred to me that a fireplace
shop may also have ceramic woll.
Eric
Heh , we don't have one of those too . This is a very small (5,000) very
isolated town - the nearest freeway is a hundred miles away more or less .
Those 'glass batts were salvaged fom a tearout , cost me the labor to load
'em up .
Today I'm working on toy boxes for my 2 youngest grand daughters .
Tomorrow I'll be setting up for the CI job , get it outta the way so I can
go back to laying cement block yecchhh for our new cellar .
Greetings Terry,
The ceramic wool I use is available from Seattle Pottery Supply for
$1.75 per square foot. This link may get you to the right page:
http://www.seattlepotterysupply.com/...gory_Code=CFIP
I live on an island north of Seattle and so I understand what it is
like to have everything you need or want far away. If you are going to
do more than just a few pre heat/post heat type repairs in the next
few years it may be wise to order a few square feet of the ceramic
wool. The stuff is great for wrapping stuff that needs to cool down
slowly. It is pretty light so shipping should be pretty cheap. And I'm
sure there is a supplier closer to you than Seattle.
Cheers,
Eric
At least being Superwool it is the safe body soluble fibre, sometimes
referred to as AES fibre (alkaline earth silicate)
http://www.morganthermalceramics.com...uperwool-fibre so not
considered carcinogenic like the RCF (Refractory Ceramic Fibre) blanket
like Cerachem, kaowool etc. Having used both though the safe stuff does
break up much more readily and is more annoying to use than the RCF
blanket, cost wise about the same. I've used Maftec blanket which is
safe, takes higher temperature like 1600C, works like RCF but what fibre
is does give off when worked is more annoying due to the larger fibre
size, it's also much more expensive.