Possible Condensation Solution?

Both good. I like a little electric heat with a fan to circulate. If a
ceiling fan, might just go with one of those mineral oil thermostatic
controlled types.


"William Robert" <[email protected]> wrote in message
news:[email protected]...
> Have you tried a ceiling fan and turning up the heat a little in the shop?
>
> "Tom Watson" <[email protected]> wrote in message
> news:[email protected]...
> > On some days, mostly in the Fall and the Spring, I have a problem with
> > condensation forming on the cast iron tops of the tools, causing rust.
> >
> > I use wax and I've tried Boeshield and Topcoat but there are some
> > days, usually when the night has been pretty cool and a warm moist air
> > mass moves in, that they are not up to the job.

Tom,
THis sounds more like a lack of insulation. Even though my shop is unheated, I did get
R13 + 3/4" plywood on the walls.
This holds the interior temperature and allows for a slow transition. Thus greatly
reducing/eliminating condensation.
Additionally, there is a lagre quantity of "stuff" in the shop adding to the thermal mass,
slowing temperature transition further. I also do no open the doors or windows until
mostly equilibrium is met.
I have had no condensation or rust problems since insulating and staying closed up as
described.
(I live in upstate NY where spring and fall temps swing wildly.)

Good luck,

Myx

"Tom Watson" <[email protected]> wrote in message
news:[email protected]...
> On some days, mostly in the Fall and the Spring, I have a problem with
> condensation forming on the cast iron tops of the tools, causing rust.
>
> I use wax and I've tried Boeshield and Topcoat but there are some
> days, usually when the night has been pretty cool and a warm moist air
> mass moves in, that they are not up to the job.
>
> I'm guessing that the cast iron has enough thermal mass that it can't
> respond to the change in temperature quickly enough, so that, if the
> humidity is high enough, the cast winds up being below the dew point
> and condensation forms. It's not a problem on the sheet metal.
>
> I was wondering if it might be worthwhile to mount a ceramic base
> light bulb fixture inside the cabinet of the tablesaw and the shaper.
> I was thinking that, if I mounted it up high in the cabinet, close to
> the table, a sixty watt bulb would provide enough heat to keep the
> cast above the dew point.
>
>
> Regards, Tom
> Thomas J. Watson-Cabinetmaker
> Gulph Mills, Pennsylvania
> http://users.snip.net/~tjwatson

On Wed, 05 Nov 2003 20:35:38 GMT, "Jim Mc Namara" <[email protected]>
wrote:

>
>I used a heating pad . . . worked just fine in the Houston humidity.
>

Hi Jums:

I use a heating pad nearly every night - for my back.

I was thinking that the light bulb idea would be cheap and easy.

(hey - weren't them the names of those twins you went out with in high
school?)


(tom assumes a defensive posture and begins to search the sky for
incoming)


Regards, Tom
Thomas J. Watson-Cabinetmaker
Gulph Mills, Pennsylvania
http://users.snip.net/~tjwatson

In article <[email protected]>,
Tom Watson <[email protected]> wrote:
>
>
>On some days, mostly in the Fall and the Spring, I have a problem with
>condensation forming on the cast iron tops of the tools, causing rust.
>
>I use wax and I've tried Boeshield and Topcoat but there are some
>days, usually when the night has been pretty cool and a warm moist air
>mass moves in, that they are not up to the job.
>
>I'm guessing that the cast iron has enough thermal mass that it can't
>respond to the change in temperature quickly enough, so that, if the
>humidity is high enough, the cast winds up being below the dew point
>and condensation forms. It's not a problem on the sheet metal.

Yup. you've got the physics of the situation *exactly* correct.

>I was wondering if it might be worthwhile to mount a ceramic base
>light bulb fixture inside the cabinet of the tablesaw and the shaper.
>I was thinking that, if I mounted it up high in the cabinet, close to
>the table, a sixty watt bulb would provide enough heat to keep the
>cast above the dew point.

"Methodology sound, implementation flawed." <grin>

The bulb _inside_ the saw is likely to get broken by stuff flying
around inside the cabinet. There is also a risk of sawdust accumulating
_on_ the bulb, and catching fire. *NOT* a good idea.

Build a (relatively) light-weight framwork to surround the piece of
equipment -- a few inches clearance on each side, and a foot or so
clearance on the top. run a diagonal member across the top, so you
can put a hook-eye approximately centered over the saw. Make a 'shroud'
that fits over the framework, and goes at least halfway to the floor.
something 'windproof' is ideal.

To use, set up the frame, hang an *incandescent* trouble-light from
the hook-eye, turn it on, and put the shroud over things.

On Wed, 05 Nov 2003 20:16:09 GMT, Tom Watson
<[email protected]> wrote:

>On some days, mostly in the Fall and the Spring, I have a problem with
>condensation forming on the cast iron tops of the tools, causing rust.
>
>I use wax and I've tried Boeshield and Topcoat but there are some
>days, usually when the night has been pretty cool and a warm moist air
>mass moves in, that they are not up to the job.
>
>I'm guessing that the cast iron has enough thermal mass that it can't
>respond to the change in temperature quickly enough, so that, if the
>humidity is high enough, the cast winds up being below the dew point
>and condensation forms. It's not a problem on the sheet metal.
>
>I was wondering if it might be worthwhile to mount a ceramic base
>light bulb fixture inside the cabinet of the tablesaw and the shaper.
>I was thinking that, if I mounted it up high in the cabinet, close to
>the table, a sixty watt bulb would provide enough heat to keep the
>cast above the dew point.
>
>
>Regards, Tom
>Thomas J. Watson-Cabinetmaker
>Gulph Mills, Pennsylvania
>http://users.snip.net/~tjwatson


Seven watt (night light) is all you need to chase away moisture. A
reptile heating stone from a pet shop will work too if you don't want
the light. A 60 watt bulb might be hazardous.

On Wed, 5 Nov 2003 15:37:57 -0500, "William Robert"
<[email protected]> wrote:

>Have you tried a ceiling fan and turning up the heat a little in the shop?
>

I was thinking that it would be cheaper to heat the object, rather
than heat the whole shop.

This problem usually occurs during the transition times of the year
when the shop heat would not be on.


Regards, Tom
Thomas J. Watson-Cabinetmaker
Gulph Mills, Pennsylvania
http://users.snip.net/~tjwatson

I agree it won't get hot enough to be a worry, but if the bulb were to break
(see the recent exploding bulb thread), whilst you were running the saw, it
might be possible to cause a fire. Obviously you would just turn the bulb
off while using the equipment, but "doodoo occurs".

--
Bill Pounds
http://www.bill.pounds.net/woodshop


"Tom Watson" <[email protected]> wrote in message
news:[email protected]...
> On Wed, 05 Nov 2003 21:10:27 GMT, [email protected] ()
> >
>
> Let's say that the ignition temperature is in the range of 400 - 600 F
> and we reduce the bulb wattage to 40W, which would have a surface
> temperature of about 240 F.
>
>
> Regards, Tom
> Thomas J. Watson-Cabinetmaker
> Gulph Mills, Pennsylvania
> http://users.snip.net/~tjwatson

"Wood Butcher" <[email protected]> wrote in message
news:y7dqb.82600$mZ5.562473@attbi_s54...
> I was thinking along the same lines Tom. In theory it should work
fine
> but in execution the light bulb has at least 2 problems.
> 1. Vibration from the tool could drastically shorten the life of the
bulb.
> 2. The wings will receive little heat from the bulb and still be
subject to
> condensation.
>
> So I got to thinking about using an old electric blanket intended for
a bed.
> This could easily be draped over the whole top to heat the wings too,
and
> is easily removable.
>
> Art


Second the electric blanket idea. Cheap, safe and you only need to set
it on the lowest setting. Just push the saw and shaper together and
throw the blanket over the top.

get a rough-service bulb

dave

Wood Butcher wrote:

> I was thinking along the same lines Tom. In theory it should work fine
> but in execution the light bulb has at least 2 problems.
> 1. Vibration from the tool could drastically shorten the life of the bulb.
snip

I have the same problem.

My shop is the 3rd stall of the garage. (there are 2 doors - 1 double for
the main garage - and 1 single for my shop.)

Last night was so humid and this morning - it got up to about 65 pretty
quickly.
I came out to the shop about 9:30 and my table saw and jointer was literally
dripping condensation.

I wiped it off only to show a nice coating of rust already.
Im thinking of just trying a cover - but I do like that heating pad.
What would be better is if I can find a temperature switch that would
automatically turn it on/off when it reaches about 55 or so.




"Tom Watson" <[email protected]> wrote in message
news:[email protected]...
> On some days, mostly in the Fall and the Spring, I have a problem with
> condensation forming on the cast iron tops of the tools, causing rust.
>
> I use wax and I've tried Boeshield and Topcoat but there are some
> days, usually when the night has been pretty cool and a warm moist air
> mass moves in, that they are not up to the job.
>
> I'm guessing that the cast iron has enough thermal mass that it can't
> respond to the change in temperature quickly enough, so that, if the
> humidity is high enough, the cast winds up being below the dew point
> and condensation forms. It's not a problem on the sheet metal.
>
> I was wondering if it might be worthwhile to mount a ceramic base
> light bulb fixture inside the cabinet of the tablesaw and the shaper.
> I was thinking that, if I mounted it up high in the cabinet, close to
> the table, a sixty watt bulb would provide enough heat to keep the
> cast above the dew point.
>
>
> Regards, Tom
> Thomas J. Watson-Cabinetmaker
> Gulph Mills, Pennsylvania
> http://users.snip.net/~tjwatson

In article <[email protected]>,
Tom Watson <[email protected]> wrote:
>
>
>On Wed, 05 Nov 2003 21:10:27 GMT, [email protected] ()
>wrote:
>
>
>>
>>"Methodology sound, implementation flawed." <grin>
>>
>>The bulb _inside_ the saw is likely to get broken by stuff flying
>>around inside the cabinet.
>
>Nah.
>
>> There is also a risk of sawdust accumulating
>>_on_ the bulb, and catching fire. *NOT* a good idea.
>>
>
>Let's say that the ignition temperature is in the range of 400 - 600 F

reasonable. paper ignites at 451 F. <grin>

>and we reduce the bulb wattage to 40W, which would have a surface
>temperature of about 240 F.

Not sure how/where you come up with that number, but it doesn't seem
unreasonable.

Something opaque, and particularly if it's a darker color than the
frosted glass, will likely get considerably hotter.

Enough to ignite? "I dunno". not a risk I'd care to take.

Now, just sticking something like a trouble-light in, when the saw
is in 'cold storage' -- that eliminates all the vibration and/or
crud-collecting problems.




>
>
>Regards, Tom
>Thomas J. Watson-Cabinetmaker
>Gulph Mills, Pennsylvania
>http://users.snip.net/~tjwatson

yeah, the cast will conduct the heat just like your momma's big skillet! :)

dave

Tom Watson wrote:
snip
>
>>2. The wings will receive little heat from the bulb and still be subject to
>> condensation.
>
>
> Won't the heat migrate through the cast iron sufficiently? I don't
> know - I'm asking.
>
>
>
> Regards, Tom
> Thomas J. Watson-Cabinetmaker
> Gulph Mills, Pennsylvania
> http://users.snip.net/~tjwatson

Would one of the "car cover" type blankets do anything in this case? I've
never had a car cool enough to worry about, but it seems to me their purpose
would be to not allow the humidity to build up under them, so the precious
metal underneath doesn't rust.

Clint

"Wood Butcher" <[email protected]> wrote in message
news:y7dqb.82600$mZ5.562473@attbi_s54...
> I was thinking along the same lines Tom. In theory it should work fine
> but in execution the light bulb has at least 2 problems.
> 1. Vibration from the tool could drastically shorten the life of the bulb.
> 2. The wings will receive little heat from the bulb and still be subject
to
> condensation.
>
> So I got to thinking about using an old electric blanket intended for a
bed.
> This could easily be draped over the whole top to heat the wings too, and
> is easily removable.
>
> Art
>
> "Tom Watson" <[email protected]> wrote in message
> news:[email protected]...
> > On some days, mostly in the Fall and the Spring, I have a problem with
> > condensation forming on the cast iron tops of the tools, causing rust.
> >
> > I use wax and I've tried Boeshield and Topcoat but there are some
> > days, usually when the night has been pretty cool and a warm moist air
> > mass moves in, that they are not up to the job.
> >
> > I'm guessing that the cast iron has enough thermal mass that it can't
> > respond to the change in temperature quickly enough, so that, if the
> > humidity is high enough, the cast winds up being below the dew point
> > and condensation forms. It's not a problem on the sheet metal.
> >
> > I was wondering if it might be worthwhile to mount a ceramic base
> > light bulb fixture inside the cabinet of the tablesaw and the shaper.
> > I was thinking that, if I mounted it up high in the cabinet, close to
> > the table, a sixty watt bulb would provide enough heat to keep the
> > cast above the dew point.
> >
> >
> > Regards, Tom
> > Thomas J. Watson-Cabinetmaker
> > Gulph Mills, Pennsylvania
> > http://users.snip.net/~tjwatson
>
>

On Wed, 05 Nov 2003 22:26:50 GMT, "Rob V" <[email protected]> wrote:

>I wiped it off only to show a nice coating of rust already.
>Im thinking of just trying a cover - but I do like that heating pad.
>What would be better is if I can find a temperature switch that would
>automatically turn it on/off when it reaches about 55 or so.


Because of the objections to the light bulb idea, for reasons of
possible breakage, I started thinking about those little heat mats
that are used for seedlings. You can get them with thermostats.

Maybe if one of these was fastened to the underside of the cast iron
top it would work. It would be out of the inside of the cabinet,
where it might be damaged. The thing could be left plugged in and
allowed to run off the thermostat.


Regards, Tom
Thomas J. Watson-Cabinetmaker
Gulph Mills, Pennsylvania
http://users.snip.net/~tjwatson

On Wed, 05 Nov 2003 21:10:27 GMT, [email protected] ()
wrote:


>
>"Methodology sound, implementation flawed." <grin>
>
>The bulb _inside_ the saw is likely to get broken by stuff flying
>around inside the cabinet.

Nah.

> There is also a risk of sawdust accumulating
>_on_ the bulb, and catching fire. *NOT* a good idea.
>

Let's say that the ignition temperature is in the range of 400 - 600 F
and we reduce the bulb wattage to 40W, which would have a surface
temperature of about 240 F.


Regards, Tom
Thomas J. Watson-Cabinetmaker
Gulph Mills, Pennsylvania
http://users.snip.net/~tjwatson

On Wed, 05 Nov 2003 20:32:30 GMT, "Wood Butcher" <[email protected]>
wrote:

>I was thinking along the same lines Tom. In theory it should work fine
>but in execution the light bulb has at least 2 problems.
>1. Vibration from the tool could drastically shorten the life of the bulb.

How about using a vibration resistant bulb like the ones used for
garage door openers?


>2. The wings will receive little heat from the bulb and still be subject to
> condensation.

Won't the heat migrate through the cast iron sufficiently? I don't
know - I'm asking.



Regards, Tom
Thomas J. Watson-Cabinetmaker
Gulph Mills, Pennsylvania
http://users.snip.net/~tjwatson

"Tom Watson" <[email protected]> wrote in message
news:[email protected]...
> On Wed, 05 Nov 2003 20:32:30 GMT, "Wood Butcher" <[email protected]>
> wrote:
>
> >I was thinking along the same lines Tom. In theory it should work fine
> >but in execution the light bulb has at least 2 problems.
> >1. Vibration from the tool could drastically shorten the life of the bulb.
>
> How about using a vibration resistant bulb like the ones used for
> garage door openers?

That may work. Better than a standard bulb anyway.

>
> >2. The wings will receive little heat from the bulb and still be subject to
> > condensation.
>
> Won't the heat migrate through the cast iron sufficiently? I don't
> know - I'm asking.

Yes it will conduct. Some. The conduction area where the wing bolts
to the main tabletop is really small compared to the area the wing has
to radiate heat from. Under certain temp/humidity conditions this may
be ok and under others maybe not. I don't know for sure either, but I
do know that the handle on a cast iron skillet can be just uncomfortably
warm when while the bottom is frying sausage.

>
> Regards, Tom
> Thomas J. Watson-Cabinetmaker
> Gulph Mills, Pennsylvania
> http://users.snip.net/~tjwatson

On Wed, 05 Nov 2003 20:16:09 GMT, Tom Watson
<[email protected]> wrote:

>On some days, mostly in the Fall and the Spring, I have a problem with
>condensation forming on the cast iron tops of the tools, causing rust.

I use a polythene sheet, with small magnets gaffer-taped on top of it
to hold it down. Most of my trouble is with condensation on the
uninsulated clear roof, which then drips down.

If you place a plastic sheet over the saw, then you trap whatever
moisture is underneath and this will condense out overnight _if_ the
dew point is reached. In my workshop, I don't have this trouble - it
doesn't get that cold at night, except at roof level. I'd suggest some
experimentation before ruling out the plastic sheet approach entirely.

For the truly obsessive and slightly geeky, Dallas iButtons are an
excellent and cheap way of logging temperatures overnight. Well worth
looking at. Condensation _is_ predictable, if you have knowledge of
temperature over night and the initial humidity.

My hand tools now live in a heated steel cupboard. This is just a
cupboard, with the anti-condensation heater from an old photocopier
mounted in the base. This is 25W, in something the size of a small
eardrobe, and is currently giving me about 10°C of extra temperature.
(15°C vs 5°C in the workshop).

I'd be a little wary of heating machines. Damp green sawdust and a
source of heat might start to ferment and start its own fire. OTOH,
my saw has DC by pile and shovel - maybe yours has efficient vacuum.

--
Die Gotterspammerung - Junkmail of the Gods

Have you tried a ceiling fan and turning up the heat a little in the shop?

"Tom Watson" <[email protected]> wrote in message
news:[email protected]...
> On some days, mostly in the Fall and the Spring, I have a problem with
> condensation forming on the cast iron tops of the tools, causing rust.
>
> I use wax and I've tried Boeshield and Topcoat but there are some
> days, usually when the night has been pretty cool and a warm moist air
> mass moves in, that they are not up to the job.
>
> I'm guessing that the cast iron has enough thermal mass that it can't
> respond to the change in temperature quickly enough, so that, if the
> humidity is high enough, the cast winds up being below the dew point
> and condensation forms. It's not a problem on the sheet metal.
>
> I was wondering if it might be worthwhile to mount a ceramic base
> light bulb fixture inside the cabinet of the tablesaw and the shaper.
> I was thinking that, if I mounted it up high in the cabinet, close to
> the table, a sixty watt bulb would provide enough heat to keep the
> cast above the dew point.
>
>
> Regards, Tom
> Thomas J. Watson-Cabinetmaker
> Gulph Mills, Pennsylvania
> http://users.snip.net/~tjwatson

I had a similar problem with the tools in my Snapon box rusting in the shop.
That little seedling mat in the bottom drawer cured the problem and when the
temperature is warm enough, it never comes on. I have been thinking about
adding a small solar panel for some cathodic protection too...

--
Kill the "termite" to reply...



"Tom Watson" <[email protected]> wrote in message
news:[email protected]...
> On Wed, 05 Nov 2003 22:26:50 GMT, "Rob V" <[email protected]> wrote:
>
> >I wiped it off only to show a nice coating of rust already.
> >Im thinking of just trying a cover - but I do like that heating pad.
> >What would be better is if I can find a temperature switch that would
> >automatically turn it on/off when it reaches about 55 or so.
>
>
> Because of the objections to the light bulb idea, for reasons of
> possible breakage, I started thinking about those little heat mats
> that are used for seedlings. You can get them with thermostats.
>
> Maybe if one of these was fastened to the underside of the cast iron
> top it would work. It would be out of the inside of the cabinet,
> where it might be damaged. The thing could be left plugged in and
> allowed to run off the thermostat.
>
>
> Regards, Tom
> Thomas J. Watson-Cabinetmaker
> Gulph Mills, Pennsylvania
> http://users.snip.net/~tjwatson

I used a heating pad . . . worked just fine in the Houston humidity.

Jim


"Wood Butcher" <[email protected]> wrote in message
news:y7dqb.82600$mZ5.562473@attbi_s54...
> I was thinking along the same lines Tom. In theory it should work fine
> but in execution the light bulb has at least 2 problems.
> 1. Vibration from the tool could drastically shorten the life of the bulb.
> 2. The wings will receive little heat from the bulb and still be subject
to
> condensation.
>
> So I got to thinking about using an old electric blanket intended for a
bed.
> This could easily be draped over the whole top to heat the wings too, and
> is easily removable.
>
> Art

"Tom Watson" <[email protected]> wrote in message
news:[email protected]...
> On some days, mostly in the Fall and the Spring, I have a problem with
> condensation forming on the cast iron tops of the tools, causing rust.
>

This maybe a bit extreme, but I have a couple of magnetic block heaters
laying around. Stick one on the table of the jointer, one on the table saw.
Easily removed when the time to make wood chips arrives.
Greg

Just a thought from (usually) a lurker. The heat wrap tape that you put
around water pipes to keep them from freezing might work well. Fasten it
up under the table surface, wings, whatever else and plug it in when needed.
James

Greg O wrote:

>"Tom Watson" <[email protected]> wrote in message
>news:[email protected]...
>
>
>>On some days, mostly in the Fall and the Spring, I have a problem with
>>condensation forming on the cast iron tops of the tools, causing rust.
>>
>>
>>
>
>This maybe a bit extreme, but I have a couple of magnetic block heaters
>laying around. Stick one on the table of the jointer, one on the table saw.
>Easily removed when the time to make wood chips arrives.
>Greg
>
>
>
>

--
"Wandering prevents one from becoming Dull and Stupid"

[email protected] () writes:


[...]

>>> There is also a risk of sawdust accumulating
>>>_on_ the bulb, and catching fire. *NOT* a good idea.
>>>
>>
>>Let's say that the ignition temperature is in the range of 400 - 600 F
>
> reasonable. paper ignites at 451 F. <grin>
>
>>and we reduce the bulb wattage to 40W, which would have a surface
>>temperature of about 240 F.
>
> Not sure how/where you come up with that number, but it doesn't seem
> unreasonable.
>
> Something opaque, and particularly if it's a darker color than the
> frosted glass, will likely get considerably hotter.

... and if the bulb is covered with sawdust it's thermally insulated
from the outside, so it will get considerably hotter, especially as
the sawdust absobrs the light and infrared radiation, so ignition
temperature can be definitly reached. Old tube-equpped TV sets caught
fire usually because all the heat-generating parts inside were covered
in dust, run hotter and got the dust to burn....

--
Dr. Juergen Hannappel http://lisa2.physik.uni-bonn.de/~hannappe
mailto:[email protected] Phone: +49 228 73 2447 FAX ... 7869
Physikalisches Institut der Uni Bonn Nussallee 12, D-53115 Bonn, Germany
CERN: Phone: +412276 76461 Fax: ..77930 Bat. 892-R-A13 CH-1211 Geneve 23

I was thinking along the same lines Tom. In theory it should work fine
but in execution the light bulb has at least 2 problems.
1. Vibration from the tool could drastically shorten the life of the bulb.
2. The wings will receive little heat from the bulb and still be subject to
condensation.

So I got to thinking about using an old electric blanket intended for a bed.
This could easily be draped over the whole top to heat the wings too, and
is easily removable.

Art

"Tom Watson" <[email protected]> wrote in message
news:[email protected]...
> On some days, mostly in the Fall and the Spring, I have a problem with
> condensation forming on the cast iron tops of the tools, causing rust.
>
> I use wax and I've tried Boeshield and Topcoat but there are some
> days, usually when the night has been pretty cool and a warm moist air
> mass moves in, that they are not up to the job.
>
> I'm guessing that the cast iron has enough thermal mass that it can't
> respond to the change in temperature quickly enough, so that, if the
> humidity is high enough, the cast winds up being below the dew point
> and condensation forms. It's not a problem on the sheet metal.
>
> I was wondering if it might be worthwhile to mount a ceramic base
> light bulb fixture inside the cabinet of the tablesaw and the shaper.
> I was thinking that, if I mounted it up high in the cabinet, close to
> the table, a sixty watt bulb would provide enough heat to keep the
> cast above the dew point.
>
>
> Regards, Tom
> Thomas J. Watson-Cabinetmaker
> Gulph Mills, Pennsylvania
> http://users.snip.net/~tjwatson