Wanted to seek some advice from people in the know about metals, etc.

I was testing Sarah's baking technique a few weeks ago (viewable here) and I think I either put in too little water (so that it boiled off midway through the cook) or possibly I just forgot to put in any water at all. A few minutes into the alcohol burn I smelled something funny, snuffed the flame, let things cool, and carefully looked inside my Titan Kettle. The results:

1) The odor (maybe something like zinc? I don't know) gave me a minor headache for the rest of the night. We suspect mild heavy-metal poisoning, right?
2) The internal spiral of aluminum flashing that I used had turned from the usual silver to bronze or copper color. Weird.
3) The bottom of the (titanium) Titan is wildly discolored, like an anodizing project gone awry. Rainbow colors.

So, obviously the problem is that these metals were heated without water (or stone, a la Tinny) or stone to act as a heat sink. So they heated up a lot more than they usually would in alcohol cooking.

What I want to know is: what on earth happened? And--is it still safe to use my Titan Kettle? Anything easy I can do to restore the original color? (or lack of color)

Thanks.

Edited by freeradical on 02/10/2008 13:07:00 MST.

I don't know much about metals so take this with a large grain of salt, but I don't think your problems would be caused by heating uncoated titanium. I would guess that it would take alot for you to heat a section of titanium pot to it's melting point, 1668 degrees celcius, never mind its boiling point. I had been using a kind of two titanium pot oven system, without rocks, for a while before tinny posted his idea involving rocks and never had any problem beside the discoloration of the pots from heating them. I pretty sure the titan pot does not have a non-stick coating. So, I'm guessing you were not breathing the fumes from burning the non-stick coating. So I am guessing there was something about the metal flashing maybe it is treated with something. I don't think you would want to use the flashing with rocks either, as all the rocks do is help regulate the temperature, the temperature can still get quite hot using rocks it just slows down the heating and cooling so you don't have to keep removing the pot for the stove.

I like Roger's answer involving the alcohol.

Edited by JasonS on 02/10/2008 14:29:58 MST.

> 3) The bottom of the (titanium) Titan is wildly discolored, like an anodizing project gone awry. Rainbow colors.
This one is easy. Ti normally does this when it gets too hot. By itself it can be ignored.

> 2) The internal spiral of aluminum flashing that I used had turned from the usual silver to bronze or copper color. Weird.
Hum - dunno. My best guess is to mumble 'intermetallics' and hide behind that. (It means some sort of alloy - but I have no idea what.)

> 1) The odor (maybe something like zinc? I don't know) gave me a minor headache for the rest of the night. We suspect mild heavy-metal poisoning, right?
First of all, if you were using a titanium pot and aluminium flashing, there should be no zinc anywhere.
Secondly, there were no 'heavy metals' around. The term does not include either Al or Ti afaik.
You MIGHT have got something from the alcohol you were burning, and which would have continued to evaporate for a while from the hot stove. Some alcohols have nasties in them. This is quite possible.

What to do about the Ti pot? Give it a good dish-wash at home. Apart from that, I can't see why you should not continue to use it - but of course I haven't seen it. As for the colour - tough. It may go over time, or it may not.

cheers

The first time I used my pocket rocket with my titan kettle something happened and a dark purple deformed spot formed on the bottom of the kettle. I have not figured out what the cause was, possibly not enough water in the kettle. It seems that the titanium in the titan kettle is not too resistant to heat?

Titanium always changes color like that. Both of my ti pots have a cool rainbow look on the bottom- blue and purple. It's normal- don't worry about it.

I think it doesn come from overheating. My 2L pot turned that way after melting snow with too little water. It's never changed back and I don't expect it will. It's all part of the beauty of titanium.

In some mountain bike parts, the builders will intentionally get the coloration. I've seen this on stems and seatposts and it looks pretty cool. Either way, from what I've read it's only an aesthetic difference.

dj

Hey that's good news about the Ti. Based on what I'd already seen on the discolored handles of my Titan, I figured it wasn't much of a problem--just had to check.

Update on the odor--my dad the architect claims that most commercial sheet metals (Al flashing included) have a really really thin coating of oil on them, and it's possible this is what caused the odor and/or discolored the aluminum as it burned off. Sensical? No?

By heating your Ti pot to a high temperature in the presence of air, you have heat tinted the pot. The oxygen in the air has oxidized the Ti. The TiO2 at varying thickness and compositions (due to contamination from the alcohol, dirt, etc.) creates the color variation.

No problem with using the pot again.

When I built mine I used the aluminum from a simple windscreen. Nothing fancy - and these windscreens are exposed to direct flame often as well. Mine discolored over time but is still fine.

Having said that...well, I don't let my pot go dry. I watch my stove's output - which I should mention I use a canister stove with the Fauxbaker setup, not an alchy smell. Honestly..I'd hedge the bad smell wasn't the Ti pan, the flashing but rather your fuel that you got a good sniff of ;-)

Burning denatured alcohol always gives off a funky odor in my experience. Manufacturer's have to put some sort of ingredient in denatured alcohol so it can't be consumed, so that is likely the source of the fumes I guess.

Always try to avoid inhaling the vapors as it burns.

You could try a scouring type product made to shine up copper or stainless steel to restore the color, but I don't know if that will work on titanium. It always works on my mom's stainless steel pots and pans. She's owned the same set for over 40 years, and they still look nearly new with no discoloration. She mainly uses a product called Cameo cleaner.

I also noticed some discoloration on my Titan after use on an alcohol burner, but most of it scrubed off with a green pad and soap back at the ranch. What's worse is the residue left by esbit tabs. And what's even worser is the residue left by my homemade wood gasifier stove, it's like tar.

Once when conducting an experiment to quantify the boil times for different diameter pots on alcohol/esbit stoves I managed to give myself a headache. Even though I conducted the work under the hood of the electric range and ran the exhaust fan, fumes permeated the room. Whatever is put in denatured alcohol must be pretty toxic!

After reading all the replies to your post I agree that it's most likely the alcohol fumes that bothered you. If I don't maintain proper ventilation I've noticed the fumes myself.

One thing you mention is the 'spiral of aluminum flashing' you use to elevate the baking cup. I used the same method for a while and then started using a few small pebbles. Now I use an even lighter weight solution. Place the batter filled cup into the pot and then fill the pot with water until the cup floats. Proceed with the boiling and simmering as usual. When you've waited the five minutes, after the flame goes out, you still have enough hot water for tea to go with your pastry.

One thing you don't mention; is you pot of the non-stick coating variety? NEVER let a non-stick pot boil dry. Lots of nasty stuff in that coating.

Edited by redleader on 02/10/2008 23:34:50 MST.

Roger C, mentioned it. Here's proof...

I guarantee you your alcy setup didn't get this hot (full bore GST is a 10000 BTU output).

I did this to silence the Nay-sayers that though one could permanently damage a Ti-Pot by dry-heating it. I put my beloved SP600 on the line to prove otherwise.

Net findings? Not with a standard backpacking stove, you aren't going to hurt anything...

Titanium Burn Test

Note - Don't do this with a coated pot... you'll burn the coating right-quick. (that's why I don't by coated pots)

Edited by jdmitch on 02/11/2008 10:37:30 MST.

Joshua-

'Note - Don't do this with a coated pot... you'll burn the coating right-quick. (that's why I don't by coated pots)'

Teflon coatings Will burn away.

But what about the 'ceramic' type used on a Vargo? I thought that stuff was pretty permanent.

From my little bit of research, the 'ceramic' coatings are simply an alternate construction / application / reinforcement of PTFE and are currently being used as a buzz word to get around some of the older stigma (and newer with all the 'overheating Teflon causes cancer' media) attached to 'Teflon Coatings' (they burn, they crack, you can't use metal implements, etc)

Teflon is simply the DuPont formulation of PTFE. Basically 100% of the 'non-stick' coatings out there use PTFE (though not all use Teflon because that's the DuPont version). The only truly PTFE free non-stick coating in existence is use on Green-Pan. Well, that and the natural patina that develops on a properly used and conditions Cast Iron piece of cookware.

Anyhow, regardless of what a company 'claims' their non-stick coating is, when pressed they will admit that it utilizes PTFE and I wouldn't dry heat any of those.

Note, pure HA (Hard Anodized Aluminum, or Halulite if you're talking with GSI outdoors) is not the same (though their Triple Extreme Non-Stick is). HA and uncoated Ti have some non-stick properties naturally (as compared to SS or non-HA Aluminum). However, due to melting point concerns I would not advise replicating my experiment with HA.

If I have correctly interpreted this thread, I can bake using two nested titanium pots with 3 rocks on the bottom and no water without damaging the pots. Has anyone done this?

Tinny does it successfully, but I've never tried it. I use water and no rocks. Look at his website, minibulldesign.com, and search in the archives on his Adventures page for 17 May.

Richard,
In case you haven't yet, look up Tinny's baking method on Minibulldesign.com. Search his blog for it or something, I can't remember exactly where it is.

The point, anyway, is that not only can you do this with Ti pots, but with Al cookware as well. My guess is that the rocks absorb all the excess heat the same way the water does. Given that heat sink, not even Al pots overheat to the point of damage.

I've done this as well using an AGG anodized aluminum pot and a silicone baking pan inside on a bed of rocks. While the pot was fine, I found it got too hot and burned the cake.

I settled on using a tiny bit of water in addition to the rocks to start. The water boils away after a few minutes so I still get some browning.

"If I have correctly interpreted this thread, I can bake using two nested titanium pots with 3 rocks on the bottom and no water without damaging the pots. Has anyone done this?"

Yes, you could do it with a canister stove and have no fear of damaging uncoated Ti.

If you use something other than a canister stove, aluminum is doable (as has been stated many times already).

To Richard

Yes, you can bake in two titanium pots without using water. I used to use a Evernew .9 liter pot and a snowpeak bowl. They nest great together. Now I use the pot that comes with the Tri-ti and a cut down evernew sierra cup.
When I originally started baking without using water, I wouldn't even use rocks. Just a baking thermometer, to keep track of the temperature and an alcohol stove that simmers. This works pretty well but you need to keep a pretty good eye on the temperature, removing to pot when it gets too hot, or you will burn whatever you are baking.
Later I discovered Tinny's video using the rocks. This helps regulate the temperature better so you don't need to constantly remove the pot from the stove.