Jan 23, 2008 at 12:59 pm #1226890
This is really just a theoretical question, as I suspect a titanium bushbuddy would be prohibitively expensive, but in THEORY, how much less would it weigh compared to the current stainless steel Ultra?Jan 23, 2008 at 1:06 pm #1417368
Rick DreherBPL Member
@halfturboLocale: Northernish California
Very roughly–not knowing whether you'd need to retain the same sheet thickness or what the specific ss and Ti alloy weights are–you can multiply the weight of the ss version by 0.55 to get an approximate Ti version weight.
Eventually, somebody's going to do this!Jan 23, 2008 at 1:16 pm #1417372
Right, I think I'll start saving for it now. Might take a couple of years to save enough!Jan 23, 2008 at 1:30 pm #1417374
"Right, I think I'll start saving for it now. Might take a couple of years to save enough!"
Maybe more before he takes on the challenge of building one ;)Jan 23, 2008 at 1:44 pm #1417378
Yeah, you'd be the guy to take on a project like that. I understand titanium sheet is*difficult* to work with…
Are there any patent issues around the Bushbuddy design???Jan 23, 2008 at 1:44 pm #1417379
I'm getting a bushbuddy amongst other things soon and when i saw this post i got excited. Please dont do that to me. Bushbuddys are already pricey, we here in the UK, commonly referred to these days as rip of britain pay twice that of our American friends so a titanium BB would required the selling of major organ or 2 via ebay. Wouldnt it be cool though.Jan 23, 2008 at 2:27 pm #1417386
Not really, it's a quite simple passive gassification style stove… in the make your own gear area someone made one out of quart and pint paint cans (available for a couple bucks each, EMPTY, at home depot or walmart)… quite a nice finish they got on it…
Found it…Jan 23, 2008 at 4:47 pm #1417409
Steven EvansBPL Member
From my memory, stainless steel comes in just slightly heavier then steel at about .29 #/in^3. The titanium I'm working with right now is about .16 #/in^3. The current bushbuddy ultra states a weight of 5.1 oz.
.16/.29=0.55 (as stated above)
5.1 oz X 0.55 = 2.805 oz.
I'll mention that the actual manufacturing of a bushbuddy would far outweigh the titanium material cost, unless of course you are doing large quantities. My friend has one and they are extremely nicely put together. He keeps bugging me to make a ti version, one day maybe!Jan 23, 2008 at 7:02 pm #1417428
Sam HaraldsonBPL Member
@sharaldsLocale: Gallatin Range
My Bushbuddy weighs in at 5.14 oz. which translates to 2.827 using the x 0.55 factor. I'm curious where the x 0.55 factor was derived from however? I seem to remember hearing one reason Fritz doesn't build titanium stoves is that the weight saving between stainless and titanium was so minimal that it didn't make sense cost-wise. If the stove weight was to be cut in half that seems worthwhile to the true gram-snob.Jan 24, 2008 at 7:29 am #1417487
I think what fritz was getting at was the absolute weight savings isn't worth the price penalty that would be paid. One would probably be talking multiple hundreds of dollars to save 2 oz (as you've shown).Jan 24, 2008 at 7:58 am #1417492
Steven EvansBPL Member
"not knowing whether you'd need to retain the same sheet thickness"
This would be the deal closer. One of the benefits to using Ti (or any material with a high strength to weight ratio) is that you can typically get away with a smaller/thinner piece while retaining the same strength.
Without looking into it, let's just say the Ti version would be twice as strong as the stainless version. That would mean we could now thin the material on it. Maybe half the thickness on all parts to retain the same strength as the stainless one.
So if we know that an identical Ti version of the BB Ultra would weigh 2.8 o.z and be twice as strong as a stainless one….a Ti BB Ultra with identical "strength" would weigh 1.4 oz – I'd pay a few hunded for that!
Of course, I'm shootin' from the hip here. :)Jan 24, 2008 at 6:31 pm #1417598
Josh LeavittBPL Member
@joshleavittLocale: Ruta Locura
Titanium is definitely strong enough if the same thickness is used, and it may even be possible to go thinner.
As for the price, there is probably some where around $6 in Stainless steel in a Bushbuddy where as it would take about $20 in titanium to build one(but dont hold me to this), so the materials are not that big of a deal. The cost of a Bushbuddy IMO is in the labor, they are very well built with great attention to detail.
Working with Titanium in the thicknesses that we are talking about is not difficult at all, in some cases it is easier to work than stainless.
The one possible down side to building a BB out of titanium may be a loss of efficiency. When stainless is used in the construction of a wood burning stove it tends to hold the heat in more than other materials. This tendancy to "insulate" is why stainless is normally not used for "enclosed" word burning stoves, ie. lower heat transfer than other metals. In the case of the BB, the "insulating effect" would actually help in the gasification process. Titanium transfers heat much better than stainless and in the case of the BB Ti may actually be a detriment to the gasification process.
On second thought, after writing all that, it could be a plus to use Ti, It might help to transfer heat into the chamber where the gasification occurs. I guess some one needs to build one.Jan 25, 2008 at 7:21 am #1417657
From my understanding the difficulty with working with Ti isn't the forming, it's the joining. Ti is notoriously difficult to weld and and rivets one might use is simply going to compromise the weight significantly. Also, I suspect your numbers are off on the cost of materials. Don't forget the rods that would be needed in the bottom of the burn chamber.
PS – if you check 304 SS vs Ti grade 2 sheet prices @ onlinemetals.com, you'll get a sense of the actual cost ratios. We're talking more like 10x multiplier for the cost of the Ti. Same ratio holds for round-bar prices.
Plus, Fritz would take even more of a cost because he's not likely to be buying Ti in the quantities that he buys SS.
Though… now that I think about it, if one really wanted to, one could probable form an insert for the Tri-Ti that could make it semi-gasifying… you'd have to block the top air holes though… hmmm… would make it less scarring too… probably expensive for the added efficiency (and added weight)… but it might be possible…Jan 25, 2008 at 9:03 am #1417676
Josh LeavittBPL Member
@joshleavittLocale: Ruta Locura
Yes Titanium is difficult to TIG weld, but it spot welds very well, and this is how a BB is put together.
Based on where you got your price info you are absolutly correct. So with out revealing too many trade secrets, I'm going to say my numbers are pretty close. And yes these numbers would be added to by some one not purchasing large quantities, plus shipping etc.
I dont think your Ti-Tri would benifit much, if at all, from a gasifiction conversion. IMO it would really spoil the simplicity of the Ti-Tri, but let us know if you do try something. One trick that I like when burning my TT is to space the whole thing off the ground about 1" with three flat rocks, or to dig three small trenches that radiate out from the center of the stove.Jan 25, 2008 at 10:51 am #1417696
Spot Welds, eh? I guess I've never seen a BB really up close. And that would make construction out of Ti pretty simple.
I agree with the simplicity of the TT. It's part of why I bought it over the BB. The gasification thing would be more 'cool proof of concept' than truly useful (which is true of most DIY Gasifiers are). I once wrote what amounted to a dissertation on DIY wood stove designs… basically the 'sweet spot' for DIY'ers, IMO, is simple a raised floor hobo stove.
The rocks and trenches are to get more air-flow, correct? Properly increasing airflow tends to be more "bang for ones buck" for bettering the performance of wood stoves.
Oh, yeah, when I doubled checked (because I knew I remembered your name from something) you'd know the price of Ti in bulk ;)Jan 1, 2009 at 2:00 pm #1467468
@tytaniumLocale: South-West Virginia
There is a manufacturer of a titanium bushbuddy style stove, the maker is fourdog dot com.
It is however heavier than the bush buddy at just over 6 ounces. Though it is a little heavier, I would think it is stronger. I ordered one a month ago, I hope to get it in another month or so. I own one of his 10 pound titanium woodstoves with flue pipe, and it is very well made.
Probably the lightest option out there for burning wood would be the titanium goat caldera cone made from titanium. They sell it as a complete kit so you could burn alcohol, esbit, or wood. I would buy the optional floor if burning wood. This system does not use the more efficient secondary burn feature, but hey the wood is probably more than plentiful.
I love this metal, it has a thousand degree higher melting temperature than stainless steel, will not corrode. If titanium products are cared for, they should last a lifetime.Jan 1, 2009 at 3:30 pm #1467487
@thomdarrahLocale: Southern Oregon
You just like ti, titanium, for the name :). If you want to see titanium art in a functional form check out Moots cycles. I own multiple Moots bikes and these are truely a work of art and they perform as well as they look.Nov 24, 2009 at 2:23 pm #1547833
David StenbergBPL Member
Resurrecting an old thread. There seems to be a titanium bushbuddy in the works that will weigh around 3.5 ounces. This information comes from an interview with the designer of the bushbuddy. Could be old news, but I thought I would pass it along.
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