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Need welders goggles?

Last time I had hubby refill my torch, he put in acetylene. He said
it’s hotter. I know that’s true. However, I’m wondering if I now need
to wear welders goggles to use it with my micro torch tip? Or, for
that matter, will I need to use it when the flame is bigger than

I took a metalsmithing class this last summer where they used
acetylene and did not use welders goggles. However, I did notice that
when I was looking at the flame (bigger than my micro torch) I went a
little bit blind. (The teacher didn’t say anything about eye
protection except regarding use of the pickle pot.)

Sun Country Gems LLC


By all means wear goggles made for acetylene torches. Mine are
didymium, and are recommended for acetylene. Don’t take a chance with
your eyes.

I would be very cautious, especially if you “went a little bit
blind,” after soldering. That is a warning.


Hi Susan,

You’re likely to get a storm of replies on this one, so I may be
chiming in too late, but…

It concerns me more than a little that you’ve got a torch that can
be “refilled” with acetylene as opposed to whatever it was intended
to burn.

The design of the mixers and tips is slightly different for each
fuel gas, and yes, it really does matter. Acetylene in a natural-gas
tip is actually quite dangerous.

The torch manufacturers go to some lengths to make it impossible to
accidentally mix gases that weren’t intended to play together. If
you husband defeated those measures, you may have a real problem.

What exact type of torch do you have? You mention a “micro torch”. Do
you mean a “little-torch”? (Little black+silver thing, as heRe:

There are a number of different incarnations of that beast,
depending on which fuel gas they’re intended to use. The torch tips
are most emphatically NOT interchangeable between propane &
acetylene. Please find out from him just what exactly he did to it
before you use it again. If he did mess with the connectors to allow
it to mount an acetylene bottle instead of the propane it was
intended for, thank him for his help, and have him switch it back.
Acetylene isn’t that much hotter, and the torch won’t run right
with it anyway. (without the right tips & regulator)

Meanwhile, about welders goggles: possibly not, but they’re a good
thing to have around. Shade 3 or so would be a good place to start.
Really, it depends on the nature of the torch. Simple acetylene+air
(b-tank or presto-lite) style torches don’t need goggles, but
acetylene +oxygen torches do. If the torch only has the acetylene
bottle, then no. If it has two bottles (acet+oxy) then yes.

Hope this helps,
Brian Meek.

Um, Brian,

The design of the mixers and tips is slightly different for each
fuel gas, and yes, it really does matter. Acetylene in a
natural-gas tip is actually quite dangerous. 

With some, especially larger torches, this can be true, since
larger orifices such as sometimes found on natural gas torches can
let an acetyelene flame flash back into the torch body, or
conversely, the tips designed for acetylene, especially smaller ones,
can be difficult to light with natural gas, which prefers larger
orifices or multiple ones.


What exact type of torch do you have? You mention a "micro torch".
Do you mean a "little-torch"? 
There are a number of different incarnations of that beast,
depending on which fuel gas they're intended to use. 

Yes, sort of. The torch body, hoses, and tips are all the same. The
things that change are available hose connectors and regulators sold
for different fuel gasses. The Smith Little torch itself, or the
tips, are NOT made differently for different fuel gasses. The
instructions supplied with the torch actually tell you the various
fuels you can use, and it ranges from acetylene, or hydrogen, to
natural gas mapp, or propane, all with the same torch and tips.

However, not all the tips are equally usable. The three smallest
size tips are useful with hydrogen or acetylene, but are virtually
useless with natural gas or propane, since you simply cannot keep
them lit. (well, you can sort of light the #3, but it’s really not
good for much beyond perhaps polishing wax models. All of the larger
tips will work safely with any of the fuel gasses, though you may not
need them all the same. With acetylene or especially hydrogen, for
example, the largest tips may be simply too much for the usual jobs
that torch is asked to do, whereas with propane or natural gas, that
number six or the number seven if you special ordered it, may be the
most used tips.

But beyond the different usability, there is no design difference in
the Little torch tips for use with different gasses. (their long
"casting/melting" tip with it’s multi orifice tip may be an
exception. I don’t know, as I don’t have one) And most of the time,
in fact, the hose connectors are the same as well, since most
regulators, even for different gasses, use standard size connectors.
If not, adapters are easily available.

By the way, this situation is not unique to the Little torch, though
that was the one I believe she mentioned. The meco midget torch, for
example, is also fine with a variety of fuels. I use mine with
propane or natural gas for jewelry, but one time I needed to do some
welding, and didn’t have a proper welding torch. You could get
different tips at that time, and acetylene tips were available. The
only difference was just that the acetylene tips were a single
orifice. But you can also get natural gas tips that are the same, and
work just as well with acetylene. Only the multi orifice tips
designed for natural gas or propane don’t work so well with acetylene
(though I doubt there’s any safety issue with them. They just don’t
work as well). With oxy/acetylene, the meco midget is a bit short for
comfortable welding, as your hand is somewhat close to where you’re
welding. You can get a longer neck to fix that. But the tips and
torch body remain the same.

With different fuel gasses, you DO need some changes. Regulators,
for one thing, are not totally interchangeable, and working pressures
for the oxygen and fuel will be different with different fuels. And
for safety, you need to know the right settings to avoid flashbacks
and the like, as well as just getting good results. But in the case
of the Little torch (and I suspect it’s close imitators too), I
believe your worries simply aren’t justified. I’ve used my little
torches with all four of those mentioned fuels at various times,
pretty much interchangeably, and the instructions from Smith verify
that this is fine to do.

In your defense, you’re correct in some cases, especially with
larger torches, and those torches intended originally just for use
with natural gas, especially those wanting natural gas and compressed
air rather than oxygen. Switching those to use oxygen can be a real
problem. That’s as much or sometimes more a concern than switching
fuel gasses. The other common issue with switching fuel gasses is
that standard acetylene welding hoses are not compatible with
propane or natural gas, so you need to use hoses specified as Ok with
propane or natural gas if you use these fuels (those hoses, though,
are fine with acetylene too.) So your cautions are indeed sometimes
quite correct. Just not, I think, in this particular case with the
little torch.

Peter Rowe

Hi Susan,

Brian’s warning about modifying a torch is right on. It might be OK,
but I would definitely recommend checking with a welder’s supply
house or other knowledgeable person that can look at your torch and
regulators about the compatibility of different gases and your torch
set-up before using it again. Torches are normally pretty safe when
properly used and cared for, but modifying them or using fuels they
were not designed for can be dangerous if not done properly. Even
though some LP and acetylene torches may appear identical, there are
internal differences in torches and regulators designed for different
gases that are not apparent with a casual observation.

As to your original question, the brightness of the metal you are
working with is dependant on the temperature of the metal, not on the
fuel you are using. LP can get metal plenty hot enough to need
goggles, such as when melting or welding platinum. If you are getting
gold or silver hot enough while soldering to need goggles, really
anything hotter than a dull red, regardless of your torch type or
fuel, you may be over-heating it. On the other hand, eye protection
is not something we should ever take lightly. When I work with
platinum, I always use goggles. When I am casting or melting white
gold, I use dark sunglasses.

The problem with goggles is that you can’t see anything but the hot
metal. The darker the lens, the less you see. Dark lenses also make
it much harder to judge temperature making the chances of
over-heating and damaging the work much higher, which is why I use
sunglasses when melting white gold. If you are working with gold and
silver and find that you occasionally get a miniature "flash bulb"
type of blind spot after working with it, maybe some sunglasses may
help. Unless you are working with platinum or other metal that
requires very high temperatures, you really shouldn’t need goggles.
Although as Alma said, they can be a handy thing to have around.

Dave Phelps

Hi Peter,

She may or may not have a ‘little torch’. I was the one who
mentioned that, so ghu knows what she’s really got. Thus my
cautionary words. When dealing in explosive gases, one should be
cautious, no? (at least until we know for sure what’s really going
on.) Once we have complete data, then we can render a better answer.
In the meantime, however, I felt caution to be more appropriate.


i too agree with most of the questions that sprung up in response to
your refillable acetylene torch…lines in particular need to be
dedicated to a single gas…its a bad practice to presume you can use
the fuel lines, cylinders, refill containers etc. interchangeably…
But to the main point about eye protection : Didymium glasses are
the best you can use other than green welders lenses…Though somewhat
hard-to-find, and do shop around once locating them as they range
from 30.00 USD from William Holland School’s supply sales, to over
180.00 USD from various vendors catering primarily to glass workers
for the same product,lens shade and frame style…Didymium lenses are
amethyst in colour and come in different gradations ( A.C.E. rated
darkness degrees) for protection from extremely bright open flames no
matter what the source. I have used them for many many years when
working with white-hot metal, flames, etc. and prefer them over green
lenses for a number of reasons including what I think is superior
protection given the heightened visibility of whatever you are
working on and no blind spots or total blindness, though temporary,
after soldering,brazing or working with glass. the link i am
attaching is to only one vendor that i beleive is the priciest of
all. It’s just to give you an idea of the styles and grades of
protection available in one place. sure, you can get green welders
lenses in many places and locally at welding supply stores or even
harbour freight type retailers, but the Didymium glasses allow you to
actually see what you are working on better than any green grade
(except perhaps the lightest!). Do
get something though- over time your eyesight becomes degraded no
matter what anyone else says- as many, if not most professionals I
know do not wear eye protection most of the time- your eyes are very
much affected by oxy/fuel flames as well as the brightness of molten
metals in open crucibles…Didymium are an old fashioned rare earth
added glass eye protection solution, but they are tried and true and
hey, amethyst just plain looks better, therefore encouraging you more
on some subconscious level to actually put them on!..The added bonus
of no blind spots then becomes secondary! and you can use them as
sunglasses as well as long as UV protection is not an issue ( some
auto glass offers UV protection so it is not necessary in those cases
while driving) when wearing sunglasses…rer

Responding to the question of what kind of torch I have:

It’s a Gentec tip and regulator. I’m pretty certain I bought the
kind for oxygen/propane, but when hubby refilled the tank he said
they told him all they refilled was acetylene in that tank. So, that
tells me I purchased the wrong kind of tips and regulators due to
hubby not knowing what fuel was in the tanks in the first place.
Originally, I bought the tanks as part of a portable unit from Home
Depot designed for bigger tasks than jewelry. I then bought the tips
and regulators to produce a smaller flame, but apparently didn’t find
out what fuel was actually in the tank (just took hubby’s word for it
and he was wrong.)

Anyway, now it looks like I’m into buying a whole new set of tips
and regulators or else a new tank set.

Regarding the statement “Acetylene in a natural-gas tip is actually
quite dangerous.”

What exactly could happen if I used the wrong tips and regulators?

Sun Country Gems LLC

HI Susan,

Ah, that makes more sense.

I wasn’t entirely sure what you had, so I was being as general and
cautious as I could.

The issue with acetylene in non-acetylene tips largely comes from
bigger multi-orifice tips. From my understanding of how they’re
made, and how they’re different between gases, there are two issues:
(A) acetylene’s corrosive to certain types of rubber, so it can
dissolve the O-rings that seal the two gas lines, which can cause
handle fires, and (B) there are differences in the ratio of sizes
between the fuel & O2 ports in the mixer part of the torch tip. (for
those that have mixers. Usually welding or rosebud tips.) not likely
to be an immediate problem, but worth knowing about. That can cause
issues with getting the flame to mix correctly, and at worst, cause
flashbacks. (Handle fires & flashbacks were mostly what I was
worried about.)

As Peter said, most of the time, you can get away with it, but it
depends entirely on what kinds of O-ring you’ve got, and how the
tips are set up. Given the way you were talking, it seemed prudent to
be cautious.

Most of this I’ve picked up over the years from talking to “the one
guy left who has a clue” at the local gas house, or reading various
torch manufacturer’s info. It may not be absolute gospel, but it
seems like a good place to start.


Didymium lenses are amethyst in colour and come in different
gradations ( A.C.E. rated darkness degrees) for protection from
extremely bright open flames no matter what the source. 

Sorry you best go look at a spectral pass diagram for didymium
lenses. It only really filters the yellow portion of the spectrum. It
allows light in other regions to pass with very little attenuation.
Didymium lenses were developed for glass workers due to the sodium
content in some glasses creating a bright yellow “sodium flare” the
didymium lens works great to filter this out but does very little for
UV or IR or other areas of the visible spectrum. There are some more
modern filters that are better at reducing harmful light levels in a
broader spectrum, one version is the AUR 92 filter from Aura lens.
The are not perfect but provide better safety for glass or metal work
in many circumstances. Sometimes you need something better like when
working with platinum or other high temperature alloys and then you
need the green welders lenses. They are a broad spectrum filter and
work quite well for reducing the light from welding or brazing but,
they also greatly limit all light so it is damn hard to see anything
through them unless the light source is very bright.

Any portion of the light spectrum from infra red to UV is dangerous
to look at if it is too bright and filters can reduce that level of
light but if they are effective in the visible portion of the
spectrum then they will reduce your vision, there is just no way
around it. So don’t feel that you are protecting your eyes if you are
working with a bright light like a torch on platinum or other intense
soldering operations if you are using didymium lenses, they are a
narrow band filter.

James Binnion
James Binnion Metal Arts

Was, do I need welders goggles. Now I want to ask about changing
gases, and whether or not you need to change out your HOSES when you
do this?

I have the Little Torch, and I have the G-Tec natural gas booster
and O2. When I read up about changing my setup in the future, it was
pretty clear that I could not use the same hoses I’m using now. I’m
one of those people who actually read the manuals, cover to cover,
no matter how big they are. The I reminder reading about
my torch said once the hoses were used for a particular gas, o2,
natural gas, LP, etc., that it absolutely could not be used for
another gas.

Wouldn’t that be more of a problem that using the same tips?

AS for bringing up your torch, and taking it down: In the Rio Grande
catalog, they gave a great reminder on how to bring up and shut down
your torch.

It’s “remember the P.O.O.P.” In this case the gas is propane, so
it’s Propane, Oxygen, Oxygen, Propane. You bring up your Propane
(gas) first, then Oxygen, then when you’re done, you shut off the
Oxygen first, then Propane. And when I read all the info I could get
my hands on, the conventional wisdom was to bleed your lines down.

The last step, after the lines are bleed down, is to release the
pressure on the “second stage” of the dual-stage regulator. It’s the
t-bar, the toggle bar that you use to dial in the psi. You turn that
counter-clockwise, so there is no pressure on it. That way, when you
open up the tank next time, the delicate diaphragm in the second part
of the regulator doesn’t get slammed with a whole bunch of pressure.

That’s how I learned how to do it. I only have to do this to the
oxygen. My G-tec booster just has an on/off switch.

Sandra b

I am most confused about what happened with the filling of tanks.
Propane tanks are designed to hold propane liquefied under pressure.
My understanding that acetylene us unstable and explosive under
pressure unless it is dissolved in a solvent such as acetone so
acetylene tanks contain acetone and an inert substrate to store the
acetylene. That is the tanks are completely different in
construction and colour coded differently as well. It is possible
that your propane cylinder was filled with MAPP which is similar to
acetylene in terms of its energy content but which can safely liquefy
under pressure like propane. I don’t know whether this is actually
the case because in Australia we can only obtain MAPP in disposable
cylinders which won’t fit on to the regulator I use for my torch. I
don’t use it for both of those reason. However it might be different

All the best

The issue with acetylene in non-acetylene tips largely comes from
bigger multi-orifice tips. 

Yes. And the main difference, other than the mixing setups a few
welding tips use, has to do with the velocity of the gas stream.
welding torches are often designed for higher gas pressures, and if
you try to use with with propane or natural gas using the usual
pressure settings you might be used to with those gasses, then those
acetylene tips either won’t burn well, or could flash back. But
flashing back is more likely, actually, using acetylene in a natural
gas tip, since the orifices tend to be larger. Either way, its an
issue usually with welding size torches, not the ones we use in
jewelry, at least most of the time.

From my understanding of how they're made, and how they're
different between gases, there are two issues: (A) acetylene's
corrosive to certain types of rubber, so it can dissolve the
O-rings that seal the two gas lines, which can cause handle fires,

I could be wrong on this, but I think you’ve got that backward. If
you go buy welding hoses, the normal hoses sold for acetylene can
only be used for that gas. Propane (especially, but natural gas too)
will eat them up eventually and you’ll get leaks. The more costly
type of hoses that are good with natural gas or propane, are also
just as usable with acetylene.

And as to O rings in the torches themselves, where do you see those?
The hose connections generally seal as brass to brass pressure
fittings, without an O ring to seal it. I have seen O rings used as
leak seals around the valves, which are then out of the gas stream,
and if they had a problem simply turning off the valve would stop any
leak. Most of these nowadays are silicone rubber anyway, which isn’t
affected by any of these gasses. The only other place I’ve seen such
O rings are sealing the connection where Prestolite or Smith Handy
Heat tips (which is the whole neck and tip together) seal to the
torch body. Both of these are Air/aceylene only, so changing gasses
isn’t possible or an issue.

(B) there are differences in the ratio of sizes between the fuel &
O2 ports in the mixer part of the torch tip. (for those that have
mixers. Usually welding or rosebud tips.) not likely to be an
immediate problem, but worth knowing about. That can cause issues
with getting the flame to mix correctly, and at worst, cause
flashbacks. (Handle fires & flashbacks were mostly what I was
worried about.) 

This is true, but I think it’s not generally a problem, since you’d
see the problem as an incorrect flame mix. Adjusting the oxygen or
fuel valves to get a correct flame mixture (oxidizing, neutral, or
reducing, etc) would negate that difference in tip structure. and
you’re correct that those “in tip” mixing setups are usually just in
torches really designed just for welding and cutting and other uses a
lot hotter than most jewelry work, so these torches are less likely
to candidates for using natural gas or propane in any case.

You’re correct, of course, that these larger torches are often not
interchangealbe for fuel gas. Designed for acetylene, they should be
used as such. But the specific small torches often sold for jewelry
work, like the meco midget or the Little Torch and it’s copies, or
Otto Frei’s “german” or “swiss” torches, are more versatile this way.
(though the two latter are better used with natural gas or propane)
The one exception to this that comes to mind (there may be others) is
the Hoke torch. Those are specifically designed with specific fuel
gasses in mind, and they’re actually marked with the appropriate fuel
gas. I’m not sure if this is marketing or an actual design
difference, since the only differences I can find are with the little
screw on tips, not the torch body, but I could be wrong. I’m not a
great fan of this torch anyway. The Hoke used to be a good torch when
it was made in the U.S.A, but the current chinese verson made in
China, unless they’ve vastly improved their quality control in the
last two years, is just plain junk. When I unscrew a torch valve to
see the valve end, I don’t want to see really rough gouged seats
that would never seal, nor find bits of shavings left over from
machining still inside the valve… It reminds me of another product
that Grobet also distributes, Sparex pickle. Also junk compared to
the cheaper, just plain pool chemical. I recall once managing to
speak to someone at Grobet wondering what that damn brown junk was
(It’s not mentioned on the MSDS they sent), and was told by some
haughty sounding lady that this stuff should be my assurance of
getting the real genuine product… Perhaps the reason I’ve not
bought Sparex since…

sorry for rambling…


After much discussion with hubby and checking what kind of fuel our
regulators and torch tips really are, we determined that they were
the type for acetylene. I think what happened was we originally
THOUGHT the tank had propane in it, but figured out at some point
that it was acetylene, purchased the correct tips and regulators,
then went back to thinking the incorrect thing again. I guess that
sort of thing comes with getting older. Such is life. At least I
won’t have to buy new anything except glasses.

So, thank you everyone for the advice about the didymium glasses.
I’ll get some of those before using the torch again. (Don’t want to
do even a tiny bit of damage to my eyes.)

Sun Country Gems LLC