Thanks to the poster who mentioned McMaster-Carr. I ordered my 12x12"
titanium screen yesterday and it came today! The timing was perfect,
because I was getting ready to sweat solder a 4-layer 61/2" bracelet
together.
The screen worked mostly great. It did bow and change a bit from
flat, most probably because I was putting a lot of heat just on one
3" edge section. I think I will cut it in half (with what, I
wonder?). It won’t be so unwieldy and I can try to minimize the
bowing on a smaller piece.
It didn’t seem to act as a heat sink at all, and it’s strong and
stiff enough to be able to put significant pressure on it without
deforming it. And it’s a flat mesh, as opposed the the thick “woven”
ones available in steel. This is a much better form.
I do a lot of heavy sweat soldering, and this sure looks like the
best solution yet. I propped it up on 3 firebricks temporarily, but
want to figure out a more stable way to support it about 6" high (no
tripods!). Any ideas?
The thing was pricey ($100), but I really think this may be the
answer I’ve been looking for. For you too?
It is possible to set the titanium wire mesh on fire with a torch.
If the Ti does start to burn you cannot put it out without a special
type of fire extinguisher (Class D). It burns so hot that it
actually disassociates water into H and O2 and just burns more. If
you are going to use it for a soldering screen be aware that this can
happen. Oxy fuel gas torches definitely are hot enough to ignite the
Ti, be careful metal fires are very dangerous.
You are much safer with a stainless steel or inconel screen as a
soldering surface
Jim
James Binnion @James_Binnion
James Binnion Metal Arts
It is possible to set the titanium wire >mesh on fire with a
torch.
Once again, Jim Binnion has scared the pants off of me. Here I find
the “perfect” soldering screen, and now this. I called McMaster-Carr
(part# 9259 K11) about it, but they could offer no further info-
which kind of surprised me.
The mesh is roughly 1mm in diameter at its thinnest point, so it is
relatively heavy. With a melting point over 3000 degrees, it’s hard
to see how soldering at 1500 degrees could start a fire- especially
since I don’t concentrate the heat in any one spot for long.
Jim, you have pulled many of us back from the brink of doing
something dangerous in the past, but is it possible you’re being
overly cautious in this case? I sure hope so! Thanks!
Take a short piece of thin (26-30 ga) Ti wire and heat it with your
torch till it ignites have a safe place to set it like a fire brick.
Don’t look at it when it is burning it is very bright. The larger the
piece is in diameter the harder it will be to make it ignite.
Titanium is called a reactive metal in part due to is great affinity
for oxygen. If you get it hot enough it will proceed to very rapidly
oxidize ( burn) in an uncontrolled fashion. Look up titanium fire on
google and you can find a little more about titanium
fires Also look at http://www.titanium.com/titanium/tech_manual/
tech15.cfm The largest group of Ti fires are in machine shops from
turning chips and grinding dust. Your screen is thinner in section
than the lathe turnings they are concerned about therefore easier to
ignite. As I said your screen may not ignite with your use of it but
it is a concern and I would not use the Ti screen for a soldering
surface in my shop.
Jim
James Binnion @James_Binnion
James Binnion Metal Arts
Jim, you have pulled many of us back from the brink of doing
something dangerous in the past, but is it possible you're being
overly cautious in this case? I sure hope so! Thanks!
he’s being a little cautious, but not totally. I personally don’t
like titanium solder picks precisely because now and then, the point
of one will get a little too hot, and suddenly melt back, burning
brightly in the process for just a moment, leaving the former sharp
point a rather bubbled knobby ugly and slightly shorter thing. When
the titanium does burn like this, it’s at a temp rather higher than I
would ever have wanted the gold to go (but lower than I’d have
required if I were soldering platinum). But titanium doesn’t
transmit heat well, so whatever part is in the hottest part of the
flame will tend to get hotter than other parts, not cooled by
conduction. A wire mesh, not having exposed sharp points, would be
harder to ignite like this than the slim sharp point of a solder pic,
but not impossible. Note that it’s not something that likely would
continue to burn more and more when you pulled the torch away. You’d
get a quick flare up of the overheated part of the mesh, with a
bright flare of light that no doubt would cause you to pull your
torch away. When you did that, the screen would go out. But it likely
would be pretty ruined by then.
Titanium DOES work very well for fixtures in the kiln for supporting
things to be enameled, or otherwise fired. It won’t get overheated to
the point of igniting in this situation.
And if you were using a screen with a thicker coarser wire size, I’d
guess the likelyhood of igniting it wouldn’t be high. But it’s still
possible. Demonstrate this for yourself with an old titanium solder
pick. You’ll quickly get an idea of what’s likely and what’s not.
You’ll only hurt the solder pick, not yourself, with this demo, and
the point of the solder pick will be easily reground.
Now, if you could find a screen made of tungsten wire…
(unlikely…)
I hope Jim doesn’t mind me adding my opinion. You must remember that
the concern is not just the temperature of the flame, but the BTU
output as well. I’ll try to relate this with two examples. Using a
00 tip on a torch using hydrogen and oxygen can produce a peek flame
temperature of 10,000 degrees but not enough thermal output to metal
3 ozs of sterling. Take a propane/air torch (such as a Turbo Torch)
with a #4 tip and a peek flame temperature of around 1600 degrees
and apply it to a tungsten rod tip. The tip of the rod will easily
reach 2800 degrees. Refractory materials (of differing degrees)
absorb heat so a higher temperature than torch temperature is
possible. In any heating operation dirt plays a roll. It would be
difficult to anticipate the makeup of the dirt,and the potential for
refractory material to be present. Using a propane or NG torch to
melt say tungsten or titanium in quantity would be inconceivable, but
to melt a piece that is a fraction of a gram not so difficult. For
something that is highly flammable such as titanium or magnesium, a
small spark is all it takes.
I think the chance of a fire is small, but does exist. I use
stainless steel screens for soldering. You just get some 300 series
SS from the rem bin at your local steel yard (screen or expanded)
and take it outside and spray it with some oil. Heat it until the oil
burns off, and it is ready for use. I flux my pieces off the screen
the first few months because soldering to the screen is still
possible if enough flux spills on the SS. The older the screen the
better. I hope this helps without actual scaring anyone. Just as a
side note, I use tungsten wire for special repetitive setups. Very
expensive, but worth it on occasion.
For what it's worth, my favorite soldering pik is a titanium
bicycle spoke. I often bring it up to a white heat but it hasn't
caught fire yet.
I use Ti soldering picks as well and I have set the end on fire but
as it got up to the area where the flux was it extinguished.The Class
D fire extinguisher basically creates a glasslike covering over the
burning metal to extinguish the fire and that is how the flux coating
on the pick acts. It is more likely to ignite when working at very
high heats like soldering palladium, and hard solders on high kt
white golds. If there is a flux coating on the pick it will not burn
but if there is not one or it has been burned off by the high
temperature then it is not too hard to set it on fire. I do not keep
the pick in the flame for the whole time of soldering but a screen
is. This is my concern. Lately there is a lot more use of Ti by bench
jewelers now and no training in the issues of working with it. It is
a flammable material it is most dangerous when finely divided like
saw dust, filings etc those are quite easy to set on fire. Fine wire
is a little harder and rod and sheet are very difficult. Once it is
burning however it can be very difficult to put out. What I am trying
to do is raise the awareness of its properties so people can make
informed decisions about its use. I find it excellent as a solder
pick but am not so certain I would use a fine screen mesh as a
soldering surface. I am very careful to clean up after filing,
sawing and machining it as most incidents involving Ti fires are from
dust and fine chips. Also it should never be ground dry as this is a
very easy way to ignite the dust pile in and around the grinder.
James Binnion @James_Binnion
James Binnion Metal Arts
I switched to using niobium picks for the same reasons… I caught my
titanium pick on fire. For the 8 years I’ve used the niobium pick,
I’ve never had a problem. Should I be watching for one?
James, You are correct in bringing the titanium burning to
everyone’s attention. I see it doesn’t take all that much heat to
ignite (theoretically). Some interesting facts in the MSDS.
Even if in practical use the risk is small, the effects of a rare
event could be catastrophic. If you pick burns its controllable…a
screen afire is a BIG deal.
I switched to using niobium picks for the same reasons... I caught
my titanium pick on fire. For the 8 years I've used the niobium
pick, I've never had a problem. Should I be watching for one?
I believe niobium is much less likely to burn than titanium. It is
however a reactive metal and its dust is listed as a fire /explosion
hazard. But almost any metal dust can be a fire/explosion hazard so
I think you are safe but I have no hard data on it.
Jim
James Binnion @James_Binnion
James Binnion Metal Arts
Thanks to all who have responded with their safety concerns. I
really want to use this thing, because it WORKS, and it cost a
hundred bucks!
I took a look at the MSDS that was mentioned and I did indeed find
some interesting facts. I’m not sure what “auto-ignition temp.”
means, but it’s 2200F for titanium in air. Does anyone know the
significance of this?
Also listed is “Extinguishing media”, which is either table salt or
a type D extinguisher. If I read this right, a can of Morton’s nearby
might suffice should an unlikely ignition occur. Am I missing
something?
This really is a fairly thick screen with no exposed points or
extra-vulnerable components. I may even smooth and polish the
section I use most. I’m sweat-soldering heavier silver pieces,
starting with extra-easy solder (so it would be closer in temp. to
easy solder during the final remelting step). I have to keep the
torch moving up and down and all around anyway, so concentrations on
any particular spot would be brief.
If I really am putting myself in significant jeopardy, I will stop
of course. But if I can mitigate the risk I’d like to continue using
it. I’d be willing to cut off a little of it to test heat, if I could
do it safely, and if it would be an accurate predictor of what would
happen heating the much larger screen.
Again, thanks to all of you out there who generously share your
knowledge!
I find it excellent as a solder pick but am not so certain I
would use a fine screen mesh as a soldering surface.
For those of you that are (were?) considering a Ti soldering screen
it may be worth noting that expanded Ti sheet is an option too. The
Ti soldering screen I’ve used for over a year now is 18 gage (AWG)
expanded sheet… so it’s certainly NOT a fine mesh. My piece is
about 2 inch by 3 inch and the cost was only a few bucks.
I'd be willing to cut off a little of it to test heat, if I could
do it safely, and if it would be an accurate predictor of what
would happen heating the much larger screen.
As I’ve been reading the posts, this is exactly what I was thinking
made sense to do-- take a piece, and heat it until it catches fire.
That way, you’ll see how much heat it takes to run into trouble, and
you may also see what happens just before it ignites, so you will
know when to back off. Since posts have indicated that the titanium
doesn’t maintain combustion once the heat source (torch) is
withdrawn, it really doesn’t seem like a major risk to me. Good to
know what could go wrong, but I, personally, would guess you’re OK.
Of course, that’s easy for me to say, I’m miles away! :>)
I use a tungsten carbide soldering pick. I made my own from half a
length of 1.6mm TIG welding torch rod.9 the bit that the spark comes
out from). I put it in a wooden handle, ground a point on the end, It
doesn’t bend when hot, or contaminate your metal or get too hot to
hold. And very cheap!!
I believe niobium is much less likely to burn than titanium. It is
however a reactive metal and its dust is listed as a fire
/explosion hazard. But almost any metal dust can be a
fire/explosion hazard so I think you are safe but I have no hard
data on it.
It’s a 3mm round rod of niobium stuck in a wooden handle, Jim! No
dust, no filings = no exploding solder pick - right? grin