N
N_Cook
Guest
On 12/12/2017 14:50, pfjw@aol.com wrote:
What scarf angle do you use for the join?
nitrile/neoprene rubber cord ?
What scarf angle do you use for the join?
nitrile/neoprene rubber cord ?
P
pfjw@aol.com
Guest
On Tuesday, December 12, 2017 at 12:32:54 PM UTC-5, N_Cook wrote:
Neoprene.
And as sharp an angle as I can manage with a fresh X-Acto blade and clean mating surfaces. I would guess around 30 degrees or so. I have a marked, slotted block so that I can set the O-ring in the block and stretch it a specific amount so each cut is the same angle. I make a sloppy joint (extra glue), then more glue, dip it in baking soda (accelerant), allow to cure, then file the flash with a jeweler's file. It almost takes longer to describe than to do it.
Here is a picture from Phil's Old Radios:
https://antiqueradio.org/art/Zenith12S471NewBeltCut.jpg
Nothing wrong with a single-edge razor.
Peter Wieck
Melrose Park, PA
Neoprene.
And as sharp an angle as I can manage with a fresh X-Acto blade and clean mating surfaces. I would guess around 30 degrees or so. I have a marked, slotted block so that I can set the O-ring in the block and stretch it a specific amount so each cut is the same angle. I make a sloppy joint (extra glue), then more glue, dip it in baking soda (accelerant), allow to cure, then file the flash with a jeweler's file. It almost takes longer to describe than to do it.
Here is a picture from Phil's Old Radios:
https://antiqueradio.org/art/Zenith12S471NewBeltCut.jpg
Nothing wrong with a single-edge razor.
Peter Wieck
Melrose Park, PA
D
Dave Platt
Guest
In article <467v2d9lchp8cnnkt648svqvindkbcrsu9@4ax.com>,
<oldschool@tubes.com> wrote:
The newer formulations, applied and used properly, seem to be better.
Plain cyanoacrylates (e.g. the lower-viscosity ones) seem to be rather
brittle. They don't deal well with materials that flex at all, and
are best reserved for entirely-rigid materials. The low-viscosity
types have very little gap-filling ability - work OK on clean breaks
but not well if the joint is rough and has any air-space.
There are newer varieties - composites of cyanoacrylate and other
materials, sometimes including what seems to be something like
nanoparticles of rubber of some sort. These are often marketed as
"toughened" cyanoacrylate. I've had better luck with these, when used
as a more general-purpose adhesive. I presume that the added materials
prevent small fractures from propagating through the solidified
adhesive. The occasional ceramic cup or dish I've repaired with the
toughened cyanoacrylate have held up OK.
Low-viscosity cyanoacrylate also makes a nice quick (and hard) finish
for small lathe-turned wood object such as pens. You can use it as a
structural fill, too... put a few drops into a hole, sprinkle in some
baking soda (sodium bicarbonate), stand back while it fumes, and wait
a minute. The result is a rock-hard white solid. To fill large
holes, do this in repeated small layers for best results (warning, it
exotherms a lot for the first few seconds - hot enough to burn you).
Another good one that a friend turned me onto, a year or two ago, is
West Marine's G/flex 655-K. It's a thickened epoxy, sold for the
purpose of repairing plastic boat hulls. It'll bond a lot of the more
difficult plastics (flashing a torch flame over them for an instant is
recommended - this oxidizes the low-surface-energy plastic and creates
bonding sites for the epoxy to react with) and it works a charm on
metal and wood as well.
My friend learned about it when he asked a supplier for a glue to use
when installing stone counter-tops. He tried it out, epoxying a
length of pipe and a flange to a piece of polished granite... just
scuffed up the surface a bit with some carbide paper and glued the
flange down. After it cured, he banged sideways on the pipe with a
sledgehammer. The epoxy didn't fail, the steel didn't fail... when
he managed to bang it free, the granite failed, and a bunch of
crystals tore out of the slab and remained firmly cemented to the
flange.
The kit isn't dirt-cheap but isn't ridiculously priced, and you get a
lot of epoxy (8.4 oz). It's become my general-purpose go-to epoxy.
>If you only glued two fingers together, you'll live.
You'll also learn why it makes good sense to buy a small bottle of
cyanoacrylate de-bonding liquid, and keep it in your shop next to the
cyanoacrylate adhesive. Cheap insurance against torn skin, and having
to admit an embarrassing oops to one's significant other
<oldschool@tubes.com> wrote:
The newer formulations, applied and used properly, seem to be better.
Plain cyanoacrylates (e.g. the lower-viscosity ones) seem to be rather
brittle. They don't deal well with materials that flex at all, and
are best reserved for entirely-rigid materials. The low-viscosity
types have very little gap-filling ability - work OK on clean breaks
but not well if the joint is rough and has any air-space.
There are newer varieties - composites of cyanoacrylate and other
materials, sometimes including what seems to be something like
nanoparticles of rubber of some sort. These are often marketed as
"toughened" cyanoacrylate. I've had better luck with these, when used
as a more general-purpose adhesive. I presume that the added materials
prevent small fractures from propagating through the solidified
adhesive. The occasional ceramic cup or dish I've repaired with the
toughened cyanoacrylate have held up OK.
Low-viscosity cyanoacrylate also makes a nice quick (and hard) finish
for small lathe-turned wood object such as pens. You can use it as a
structural fill, too... put a few drops into a hole, sprinkle in some
baking soda (sodium bicarbonate), stand back while it fumes, and wait
a minute. The result is a rock-hard white solid. To fill large
holes, do this in repeated small layers for best results (warning, it
exotherms a lot for the first few seconds - hot enough to burn you).
Another good one that a friend turned me onto, a year or two ago, is
West Marine's G/flex 655-K. It's a thickened epoxy, sold for the
purpose of repairing plastic boat hulls. It'll bond a lot of the more
difficult plastics (flashing a torch flame over them for an instant is
recommended - this oxidizes the low-surface-energy plastic and creates
bonding sites for the epoxy to react with) and it works a charm on
metal and wood as well.
My friend learned about it when he asked a supplier for a glue to use
when installing stone counter-tops. He tried it out, epoxying a
length of pipe and a flange to a piece of polished granite... just
scuffed up the surface a bit with some carbide paper and glued the
flange down. After it cured, he banged sideways on the pipe with a
sledgehammer. The epoxy didn't fail, the steel didn't fail... when
he managed to bang it free, the granite failed, and a bunch of
crystals tore out of the slab and remained firmly cemented to the
flange.
The kit isn't dirt-cheap but isn't ridiculously priced, and you get a
lot of epoxy (8.4 oz). It's become my general-purpose go-to epoxy.
>If you only glued two fingers together, you'll live.
You'll also learn why it makes good sense to buy a small bottle of
cyanoacrylate de-bonding liquid, and keep it in your shop next to the
cyanoacrylate adhesive. Cheap insurance against torn skin, and having
to admit an embarrassing oops to one's significant other
N
N_Cook
Guest
On 12/12/2017 17:58, pfjw@aol.com wrote:
So you don't roughen the surfaces with glass/sandpaper?
Re elsewhere in this thread:- I'd picked up a bottle of superglue
de-bonding , for such a finger-bonding emergency.
Went to use it and the bottle was totally empty, the liquid had
completely diffused? through the glass/cap , not a trace left, hence the
procedure in the original post.
So you don't roughen the surfaces with glass/sandpaper?
Re elsewhere in this thread:- I'd picked up a bottle of superglue
de-bonding , for such a finger-bonding emergency.
Went to use it and the bottle was totally empty, the liquid had
completely diffused? through the glass/cap , not a trace left, hence the
procedure in the original post.
P
pfjw@aol.com
Guest
On Tuesday, December 12, 2017 at 2:49:51 PM UTC-5, N_Cook wrote:
I do not, no. I want as clean a surface for bonding as possible. Soft neoprene O-Rings have enough surface texture, even when cut, to hold the glue. In my mind, the key to the process is the second dip + baking soda. Chip off the excess, then file smooth with a good jeweler's file. Nice thing about these files is that they remove hard stuff, but more-or-less don't affect soft materials, unlike sandpaper.
Peter Wieck
Melrose Park, PA
I do not, no. I want as clean a surface for bonding as possible. Soft neoprene O-Rings have enough surface texture, even when cut, to hold the glue. In my mind, the key to the process is the second dip + baking soda. Chip off the excess, then file smooth with a good jeweler's file. Nice thing about these files is that they remove hard stuff, but more-or-less don't affect soft materials, unlike sandpaper.
Peter Wieck
Melrose Park, PA
J
Jon Elson
Guest
N_Cook wrote:
hot enough for the water to be driven out, the packs come apart and the
dessicant material spills out. Usually, it is actually some kind of clay
than silica gel.
Jon
The problem is most of the packs are heat-sealed together, so if you get it
hot enough for the water to be driven out, the packs come apart and the
dessicant material spills out. Usually, it is actually some kind of clay
than silica gel.
Jon
D
Dave Platt
Guest
In article <1tWdnRb4zMTmyK3HnZ2dnUU7-ROdnZ2d@giganews.com>,
Jon Elson <jmelson@wustl.edu> wrote:
So I found out the hard way. :-(
I tried to do this in an ordinary electric oven. I was careful to set
the operating temperature to the heat that the pack label indicated
was correct for renewing the packs.
Unfortunately, what seems to have happened is that the temperature of
the tray on which I placed the packs, ended up significantly higher
than the air temperature in the oven (not surprising since a lot of
the heat is radiated from the heating coils). The plastic packets
melted wherever they touched the tray, on the lower of the two trays
in the oven.
I suspect that these sorts of packs would be better refreshed in a
forced-air convection oven, where the black-body temperature of the
surfaces doesn't rise above the air temperature by more than a bit.
Jon Elson <jmelson@wustl.edu> wrote:
So I found out the hard way. :-(
I tried to do this in an ordinary electric oven. I was careful to set
the operating temperature to the heat that the pack label indicated
was correct for renewing the packs.
Unfortunately, what seems to have happened is that the temperature of
the tray on which I placed the packs, ended up significantly higher
than the air temperature in the oven (not surprising since a lot of
the heat is radiated from the heating coils). The plastic packets
melted wherever they touched the tray, on the lower of the two trays
in the oven.
I suspect that these sorts of packs would be better refreshed in a
forced-air convection oven, where the black-body temperature of the
surfaces doesn't rise above the air temperature by more than a bit.
A
asdf
Guest
On Mon, 11 Dec 2017 08:26:33 +0000, N_Cook wrote:
Ammonia is the natural solvent of cyanoacrylic glues such as
superglue. Very cheap and totally safe for the skin, but use
it outside and don't inhale it!
Ammonia is the natural solvent of cyanoacrylic glues such as
superglue. Very cheap and totally safe for the skin, but use
it outside and don't inhale it!
M
Mike
Guest
In article <lj56ge-ov8.ln1@coop.radagast.org>,
Dave Platt <dplatt@coop.radagast.org> wrote:
Or alternatively take the silica gel out of the assorted paper, plastic
and other packets, and dry it loose en-masse.
Then repack it into a re-usable/re-sealable cloth bag to contain it, and
yet allow passage of moisture into the crystals.
--
--------------------------------------+------------------------------------
Mike Brown: mjb[-at-]signal11.org.uk | http://www.signal11.org.uk
Dave Platt <dplatt@coop.radagast.org> wrote:
Or alternatively take the silica gel out of the assorted paper, plastic
and other packets, and dry it loose en-masse.
Then repack it into a re-usable/re-sealable cloth bag to contain it, and
yet allow passage of moisture into the crystals.
--
--------------------------------------+------------------------------------
Mike Brown: mjb[-at-]signal11.org.uk | http://www.signal11.org.uk
N
N_Cook
Guest
On 14/12/2017 20:05, Mike wrote:
Thats what I do. A large ex-pickle jar with bulk activated cilica gel
crystals, slightly buff colour , not pure white.
Then cut off the inside pocket cloth of worn trousers before dumping ,
tied off with crystals in, when required
Thats what I do. A large ex-pickle jar with bulk activated cilica gel
crystals, slightly buff colour , not pure white.
Then cut off the inside pocket cloth of worn trousers before dumping ,
tied off with crystals in, when required
B
Bob Engelhardt
Guest
On 12/12/2017 1:46 PM, Dave Platt wrote:
FWIW - the epoxy variety is G/flex 655. The "-K" is the repair kit.
"-8" is just the 8 oz of epoxy ($26 at Amazon). Also available in the 5
gallon size for $860.
FWIW - the epoxy variety is G/flex 655. The "-K" is the repair kit.
"-8" is just the 8 oz of epoxy ($26 at Amazon). Also available in the 5
gallon size for $860.