[Soldering] Gases and Ventilation Questions

Jewelry Discussion
1

Hello, Everyone!

I have a question regarding ventilation. We are converting a
bedroom in our house to a workstation, including soldering. Here
are the basics of what we have: 10’ x 10’ room. Bare walls and
floor. 3’ x 3’ window on one wall. Mapp gas (14-oz. cylinder)
with a minitorch. We only use sterling silver. I’ve read several
threads about Mapp gas being essentially too hot for silver. True
or false? Does our room have adequate space for ventilation, or
are we running a serious risk with our health? Do the the small
(16-oz.) disposable canisters of propane require an oxygen mix?

We use propane at our club’s shop, so the first time we ever
used Mapp was tonight, with no success. To my mind, it looked
like the Mapp gas was heating the silver and paste solder too
fast for it (the silver solder) to flow – it looked like it just
burned up!

Any advise?

Thanks bunches,
Cheryl

2

Cheryl, I don’t use a minitorch, I use a prestolite type torch
but have use an acetylene/air mix for some time and have been
quite happy with it. It is easy to work with and inexpensive.
I do recommend ventilation and MAKE SURE your paste solder is
cadmium free. A friend of mine just called me this week with a
horror story about someone very ill from overexposure to
cadmium. Ventilation doesn’t have to be costly.

Deb

3

Cheryl I have been using a Bernzomatic mini torch with MAPP gas
for sterling silver work for a number of years. It works quite
well, but you have to control your flame and heat very
carefully. With a bit of practice you can do almost anything
with the mini torch and MAPP. The one drawback that I find is
that I can not work on anything much bigger than a 2" x 2"
piece of silver, because the mini torch does NOT have enough
heat for larger pieces.

I would prefer to use acetylene/air- Prestolite- but I do not
like to have acetylene B tanks in my home for safety reasons. A
MAPP gas leak is really almost as bad as an acetylene leak, but
the MAPP tanks are really small and contain much less gas which
is more likely to dissipate and less likely to cause damage.
many orchid members disagree with my opinions on soldering
gasses. You might want to do a search on the orchid archives
for a thread about a year ago that I participated in, in which
there was much discussion about gas safety. Search the archives
for propane and acetylene.

For ventilation, its not the size of the room that counts, its
the number of air changes. I also work in a 10 x 10 room in the
basement with no windows. I installed a kitchen stove fan hood
above my soldering station and pickle pot to pick up the fumes
at the source. The fan vents outside of the house through the
basement wall. Adequate ventilation is not an option, it is a
must.

Hope this helps

Milt Fischbein
Email @mfisch1

4

I, too, was concerned about having an acetylene “B” tank in my
home. Prestolite makes regulators for “MC” tanks which are not
much bigger than the disposable MAPP gas tanks from Home Depot.
That’s the route I took and I’ve been very pleased with the
set-up.

5

Milt, Very excellent commentary, thank you.

I have a question, can the stove vent feature be mounted under,
or behind the work space in order to vent away from the nose and
lungs? If under, the work bench would of course need open space
for the vapors to be vented out. Perhaps the last third of the
bench can be screening of some type.

Teresa

6

I cannot see exhausting from under the soldering pan . . . fumes
rise, so this kind of installation may not be efficient.

My furnace man made a surround with a hood (about 38" square and
about 2 feet high) . . . picture an EZ UP tent-- with three
walls-- front open, and a pipe coming out of the top (also a
light inside). The exhaust fan is remote . . . about 18 feet
away and it vents out to the outside. Duct work goes from the
top of the surround, through the fan, and out. The fan was the
most expensive part of this set up. It is very efficient . .
. the fumes are pulled up as I solder, and I turn off the fan
when I am not soldering.

7

I feel kind of ignorant, but what is so dangerous about an
acetylene “B” tank? I also have oxy-acetylene “C” tanks in my
home and wasn’t aware of any danger other than common sense.
Please educatate me! Susan.

8 
For ventilation, its not the size of the room that counts, its
the number of air changes.

This is a good point. The number I’ve heard over and over is 6
complete air changes per hour. So by calculating the volume of
your space, you can figure out the minimum CFM your exhaust fan
needs to be. You also need to provide for an intake of fresh air
to replace what you’re exhausting.

Rene Roberts

9

You can use standard ducting for venting a soldering station.
3-4" diameter works well. The standard fitting that goes from a
rectangular duct to a round duct makes a good collection funnel

  • it can have the rectangular opening on the bench behind the
    soldering station and raised enough to be even with or a little
    above the work. At the back of the bench you have the round end
    of this fitting and you can add a 90 degree elbow and go right
    down through the bench. From there, vent to you blower and the
    outside anyway you want with flexible aluminum duct.

Tom Kruskal

10

Jenn-air cooktops do well with stovetop down venting. The one we
had also had an overhead vent.,but the downdraft did a good job
at the cooktop. I plan on getting another but it will also have
an overhead system that is there now. The classic chemical fume
hoods also have an exhaust from the bottom backside. On these you
also have downward sliding door that is kept as closed as
possible. Just general Jesse

11

Teresa In response to your question…

 ..."I have a question, can the stove vent feature be mounted
under, or behind the work space in order to vent away from the
nose and lungs?".....

If you have a strong enough fan, you can mount behind or
probably even under, BUT YOU MUST VENT YOUR SOLDERING FUMES
OUTSIDE.

When I took classes at the Alberta College of Art and Design,
they had their soldering ventilation set up behind the work.
Their fans were very powerful and there seemed to be no problem
sucking the fumes out. Most stove vents do not have strong enough
fans to mount behind or under. Since the fumes will naturally
want to travel up, my ventilation is mounted above and a bit
behind. The fumes flow up and backwards away from my face.

Milt

12 
 ......."I feel kind of ignorant, but what is so dangerous
about an acetylene "B" tank? I also have oxy-acetylene "C"
tanks in my home and wasn't aware of any danger other than
common sense.

Susan, The only sure way of not having a flammable gas
explosion
in your home is to not have any flammable gases stored there at
all, but if you must have gases in your home, minimizing the
quantity of gas will reduce the size of the fire/explosion if
one does happen. If you have a small leak and good ventilation,
the gasses will probably dissipate without incident. The
concern is more with a large leak that empties the whole tank
into your home. More gas means a larger explosion. Its a bit
like the difference between storing a few firecrackers in your
house verses a case of dynamite! There is a lot of good
on soldering gasses and their properties in a couple
of older orchid threads - July 1997 and also may 1998. Milt

13

Hi Susan,

  I feel kind of ignorant, but what is so dangerous about an
acetylene "B" tank? I also have oxy-acetylene "C" tanks in my
home and wasn't aware of any danger other than common sense.

There really isn’t anything anymore dangerous about a ‘B’ tank
in a home than in anyplace else, except the people. If they don’t
understand what’s in the tank or how to handle the tank or it’s
contents, it can be dangerous no matter where it is.

This is true about just about anything, tools, gases, cars,
guns, and on and on. The danger comes from the misuse of the
item.

All of that said though, there are some tanks that are more
susceptible to damage than others. Actually, it’s not the tank
that’s susceptible to damage but the valve. The valve on a ‘B’
tank extends about 3" above the tank, all of it unprotected. An
‘MC’ valve extends about 2" above the tank, also unprotected.
There are other larger tanks that provide a protective collar
(similar to the collar on a 5 gal/25# propane tank) around the
valve.

Of the 3 types of tanks the valve on the ‘B’ tank is the most
susceptible to damage if the tank falls over unexpectedly. All
acetylene tanks, no matter where they’re used or stored, should
be restrained in some manner to prevent them from accidentally
falling over.

There are date codes stamped in all compressed gas cylinders.
All compressed gas tanks and valves are tested on a scheduled
basis. Companies refilling tanks are required to test tanks
before refilling if the tank is ‘out of date’.

All combustible gases should be stored in a cool, well
ventilated area. They should also be prevented from falling over
(chained or otherwise tied to a sturdy support) and from other
external damage.

Most combustible gases have a distinct odor to them, or if
odorless, they have an odorant added before being sold. These
odors make it possible for the average person to detect the
presence of even a small, non explosive amount of the gas in an
area. If a gas aroma is detected, others should be prevented from
entering, the source of the gas identified, the gas shut off and
the area ventilated.

Depending on the source of the gas, the tank should be returned
to the supplier or a qualified company (person) called in to
repair any defective piping.

Dave

14 
Of the 3 types of tanks the valve on the 'B' tank is the most
susceptible to damage if the tank falls over unexpectedly. All
acetylene tanks, no matter where they're used or stored, should
be restrained in some manner to prevent them from accidentally
falling over

excellent post

i will add that this is why the cap absoluty must be in place
while transporting. even if it means an extra trip just to get
the cap.

remember the old a team show, welding tanks will fly that
energetically, just not straight.

15

I was very nervous about having gas in my house because of the
possibility of explosion but I wanted the torch to do my
soldering so I had to compromise a bit. We built a box on the
outside wall of the house with the top attached to the bottom of
what used to be a green house window. This window is directly
across from my work bench so the top of the valves are reachable
from the back of the counter. A fan is installed in a vent at
the bottom of the box which vents outside.So, when I’m working
the top of the box is slid open the valves are exposed and the
fan is turned on which draws any fumes around the tanks to
outside and the tanks are contained in an upright manner. Hope
you can adjust this to your work area. Lisa

16

Milt:

While I appreciate your cautions about having flammable gasses
in the home, I agree with Susan. If you educate yourself as the
care & handeling of these cylinders, there should be no problem.
They are safety checked every time they are refilled and if an
acetylene cylinder is leaking, you sure as heck should be able to
smell it!! As for flammable gasses, consider that most of us
live with natural gas or propane every day at home & work.

Respectfully;
Steve Klepinger

17 
 ......."As for flammable gasses, consider that most of us
live with natural gas or propane every day at home & work".

I guess that we will just have to agree to disagree.

I have worked with flammable gasses for the last 20 years. I am
a senior design engineer with Esso which is an Exxon affiliate
in Canada. I design the gas plants that produce propane and
other flammable gasses. I also do safety reviews on other
people’s designs. Over the years I have learned to have the
utmost respect for these gasses. They can be used safely for
years and then one mistake like leaving a torch slightly open
and going for a lunch break…

Coincidentally, yesterday, here in Calgary where I live, a small
oil refinery that was 40 yrs old blew up It burned for 10 hours
and when the fire was finally put out, there was nothing left. 5
were injured and two are missing and presumed dead. These
people too worked with this stuff everyday. (OK so this example
is a bit dramatic! you can see the pictures for yourself at
http://www.canoe.com)

If you must use flammable gasses (and as jewellers we must) then
respect them and use them as safely as possible.

Regards
MILT

18

Dear Milt,

I solder and cast in my home studio. I would love to hear your
suggestions on how to maximize safety in my studio. Also, you
may be able to answer a question I’ve been wondering about. Can
I use two torches in casting, one acetylene and one Mapp at the
same time if I’m melting large quantities? I’ve used two of
acetylene several times but I want to know it’s safe before I
try mixing.

Thank You,
Pauline

19

Milt, I appreciate your caution! I am about to get an
aceytaline tank to augment my current propane and oxygen with the
"little" torch set-up. We jsut had a small earthquake (2.5 this
am) on the fault (Hayward) which is a block from my house in
Berkeley. Naturally, it makes me want to be sure I am properly
equipped with straps and a secure home for the straps to screw on
to before I bring the new tank into my studio. I would
appreciate suggestions from everyone out there as to the safest
method for securing a tank, especially in earthquake country!
Shael

20

Yes, having tanks of flammable gasses in homes, or in vehicles
as we transport to and from the refilling station is DANGEROUS.
However, driving or riding in a car is as well, our own or others
driving, mechanical failures (8 to 25+ gallons of fuel or fuel
vapor in the tank. One gallon of gas can be as explosive as 50
pounds of dynamite.). We MUST take all due caution in what we
do, but lets not get too paranoid. From my recollections of
College Psychology, excess fear CAUSES many accidents, reasonable
care, reviewed regularly, should help reduce accidents. Or we can
all move into a deep cave miles from the nearest road or trail,
oh no, what about an earthquake! Know where there is a low
temperature desert?

Seriously though, I’ve learned from an Insurance Underwriter,
all professions and hobbies, in deed all human activities involve
risk, let’s calculate and reduce the risks we can. Then, “What
Me worry??” One suggestion I’ll make, if you’re reading this, you
have a computer (& printer?). Make and revise your own safety
notes attached to your equipment. A little reminder in changing
formats may sublimely ‘program’ the brain into safer habits
patterns?

Relax, have fun being safe and creative! efw

{Forgive my attempts at humor, if you need to, but worry kills
as well as stifles creativity. By the way many who know me call
me a safety nut case.)