Kathy Forer on mon 31 oct 05
Is there any "best way" to remove those thinly threaded sheet metal
screws, often rusted, that hold the metal case of the power supply,
switches and sitter in place?
The screws loosen by hand or with a socket wrench but then seem to
get stuck in place, going round and round, but not coming out,
needing to be pulled out with pliers as nothing else seems to move
them. Then they don't hold properly once attached back into the
stripped out kiln brick. I've substituted larger screws, or wider
threads, but that can't be the answer.
Should the hole be filled with kiln cement before reattaching the
switch box?
Kathy
www.kforer.com
Arnold Howard on mon 31 oct 05
The screws may have been over-tightened at the factory when the kiln was
made. They are installed with air-powered screw guns. I rarely have problems
removing the screws on a used kiln, though.
I suggest replacing the screws with larger ones. The standard is 1/4
hex-head with #8 threads. You might try 1/4 hex-head with #10 threads. The
handiest tool to use is an inexpensive 1/4" nut driver, which is like a
screw driver except that the head is a socket.
You do not need to use kiln cement in the screw hole, because the sheet
metal holds the screws in place and not the firebricks.
To remove screws that spin inside the screw hole, you might try placing
pressure on the screw as you rotate it counter-clockwise. Lift up on the
switch box to apply pressure as you turn the screw.
Sincerely,
Arnold Howard
Paragon Industries, L.P., Mesquite, Texas USA
ahoward@paragonweb.com / www.paragonweb.com
From: "Kathy Forer"
> Is there any "best way" to remove those thinly threaded sheet metal
> screws, often rusted, that hold the metal case of the power supply,
> switches and sitter in place?
>
> The screws loosen by hand or with a socket wrench but then seem to
> get stuck in place, going round and round, but not coming out,
> needing to be pulled out with pliers as nothing else seems to move
> them. Then they don't hold properly once attached back into the
> stripped out kiln brick. I've substituted larger screws, or wider
> threads, but that can't be the answer.
>
> Should the hole be filled with kiln cement before reattaching the
> switch box?
Vince Pitelka on mon 31 oct 05
> I suggest replacing the screws with larger ones. The standard is 1/4
> hex-head with #8 threads. You might try 1/4 hex-head with #10 threads. The
> handiest tool to use is an inexpensive 1/4" nut driver, which is like a
> screw driver except that the head is a socket.
Arnold -
Good advice, as usual, but the hex-washer-head sheet-metal screws with #10
threads normally take a 5/16 socket or nut driver. I agree that the
solution is usually to go up from the #8 screws to the #10 screws. Also, I
think what Kathy was referring to is screws that have corroded with time.
Often, they are badly corroded right where they pass through the sheet
metal, and thus you can turn and turn them and they do not extract. In that
case, I grab them with a small pair of vice grips and pull on them while
unscrewing them. That usually works.
Best wishes -
- Vince
Vince Pitelka
Appalachian Center for Craft, Tennessee Technological University
Smithville TN 37166, 615/597-6801 x111
vpitelka@dtccom.net, wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka/
http://www.tntech.edu/craftcenter/
William & Susan Schran User on tue 1 nov 05
On 10/31/05 3:19 AM, "Kathy Forer" wrote:
> The screws loosen by hand or with a socket wrench but then seem to
> get stuck in place, going round and round, but not coming out,
> needing to be pulled out with pliers as nothing else seems to move
> them. Then they don't hold properly once attached back into the
> stripped out kiln brick. I've substituted larger screws, or wider
> threads, but that can't be the answer.
You found the answer. Most of the sheet metal screws are steel and are prone
to rusting & corrosion.
When removing them, as you turn the wrench, wedge a screwdriver behind the
screw head to keep outward pressure on it.
When you replace the screws you can probably use the same size, though
sometimes you need to go one size larger in diameter.
Be sure to replace with stainless steel screws.
The screw is held in place with the metal skin of the kiln, not the fire
brick.
No, you don't have to fill the hole.
-- William "Bill" Schran
Fredericksburg, Virginia
wschran@cox.net
wschran@nvcc.edu
Kathy Forer on tue 1 nov 05
Thank you Bill, Vince & Arnold. I hadn't quite realized that it's the
sheet metal of the kiln skin holding the "sheet metal" screws in place.
Some of the rusted, corroded screws I recently removed looked more
like nails there was so little thread remaining. I'll try clean new
#8 screws before moving up a size.
Kathy
--
Kathy Forer
www.kforer.com
pdp1@EARTHLINK.NET on tue 1 nov 05
Hi Kathy, all,
Too, sometimes, when confronting rusted Sheet-Metal Screws, one can turn the
whole thing they are on, so that the Screws are uppermost, and put a little
Muriatic Acid ( 50/50 to Water mix ) on them so that it will dribble or flow
'down' onto their threads.
One may nuetralize the residu after with a hevy Baking Soda and Water mix.
In fact, it is a polite gesture to have a quart or gallon of wuch Baking
Soda and Water mix handy and at-hand, whenever one is working with Acids in
these kinds of ways...just-in-case one needs to neutralize a little mishap,
splash or spill, pronto.
If the rusted Screws are greasy or oily for some reason, the Acid will not
be able to get through t he Oil or Grease, so this regimen will not help at
all, but if non oil contaminated rust, the Acid Water mix will dissolve the
rust fairly quickly ( have lunch, come back and pull them). Or, in fact,
small successive applications over an hour or something will be the best, if
that much even, is needed.
Sometimes of course Steet Metal screws may become overtightened and strip
the thread bearing area of the Sheet Metal they are in, (almost never, or
that of the screws themselves) and the way these Screws tend to be designed,
their thread may not actually go all the way to terminate under their Screw
Head as nicely as one could have hoped, making matters worse, since that
ares has little or no thread to it anyway.
If this is the problem, then as others have mentioned, prying up with
something thin to make an outward pressure to coaxe the Screw as you rotate
it, then needle-nose Pliers to continue to pry with once there is enough
threaded shank to get a grip on, will work well.
Relocating the item these Screws hold on to the sheet Metal ( a 1/4 inch or
something, when possible, ) can allow nice, fresh holes. And, useing
washers under their heads if their threads do not come up high enough to
satisfy. Or, one may drill out and enlarge the holes of the thing to be
held, and graduate to the next or second from next size of Sheet Metal
Screw, useing the old holes and same registration.
Merely 'frozen' corroded Screws, Bolts, Nuts or their likes, whether of the
Sheet Metal kind or not, sometimes are encouraged to loosen with reasonable
force, or to become easier to get out if one heats them briefly with an
Oxy-Acetylene Torch, to a nice Cherry 'red', but only for a moment, then
lets them cool.
Sorry for the delay in reply...! - been pretty busy here...!
Phil
Las Vegas
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