I was thinking about it because I really love lugged frames because they have so much character / soul, but I also prefer not to use fossil fuels.
Since I’m pretty young, fossil fuels are likely to significantly increase in price and get more difficult to acquire within my lifetime as they get more scarce and less commonly used.
So I was thinking what about hydrogen?
I looked it up and a hydroxy flame seems to be the same temperature as oxy propane and seems to already be in use for brazing in heat pump manufacturing.
The flame outputs no CO2 or CO and can be produced on demand by electrolysis with electricity and water.
Downsides are that the flame produces water which I imagine could get messy with flux?
And that such a hydroxy-on-demand setup would eat quite a lot of power and I imagine it could be very pricy because you need exceptionally corrosion resistant electrodes such as titanium.
But then again, renewable energy powered brazing and never having to buy or store gas again? Seems very attractive to me.
Some are probably thinking just TIG weld the damn frames, it’s a much cleaner and more energy efficient process and you are objectively correct but also missing the point.
All you actually need to make acetylene is carbon (which you react with calcium oxide to make calcium carbide, which you then mix with water to get the acetylene). So if you wanted “sustainable” acetylene you could use charcoal rather than coke. And this might be something you could do at home:
I think you can also get a device called an “oxygen concentrator”. So maybe you could make a completely ghetto setup that didn’t involve buying any bottles of anything from the welding supply store. Agree that would be neat!
Even if you do use commercial acetylene (which I assume is made from coke) it’s a tiny amount of fossil fuel compared to the vast amounts currently burned in power stations and vehicles of various kinds. So I wouldn’t worry about it, and it will surely be available for the foreseeable future.
If you go and buy a bottle of hydrogen it will have been produced in a way that used a lot of fossil fuels anyway, as this is currently the cheapest way to do it (although other processes are available-- you could split water with electricity from a windmill for example).
Oh yes absolutely, I’m just thinking out loud for let’s say 30-50 years in the future and whether tomorrow’s solutions could have valuable benefits today.
I’d rather not fiddle with DIY acetylene setups though, I’m not known to be the most cautious person around dangerous things so I’d rather protect myself from that I do have an oxygen concentrator though to use with propane.
Ah I see, yes propane is certainly a fossil fuel! But even in 30-50 years we will use fossils for things like this that need it. If we cut back on using them for energy generation and transport the amount left would be pretty negligible (and easily offset by planting a few trees, but it would make no difference either way).
Yes that’s true, supplies of these fuels should indeed last far longer for small scale applications like brazing when they are no longer being consumed on an immense scale by energy production and transportation.
I guess my mind just likes to wander and go look at different and interesting ways of doing things.
I might still make a DIY hydroxy generator one day to test the feasibility and explore the benefits, I’ve played with DIY hydroxy generators before but only little ones incapable of sustaining a constant flame.
IIRC steel airframes are not welded with hydrogen as the fuel gas due to hydrogen embrittlement. If it’s not safe enough to fly (and take off and land) then I wouldn’t consider it safe enough for a bicycle. Brazing could introduce less hydrogen than welding but I sure wouldn’t like to find out the hard way.
It’s been about 20 years since I was in engineering school, but in the early 2000s there was a lot of excitement about hydrogen as an automotive fuel. (The “hydrogen economy” was part of both Bush’s and John Kerry’s energy plans in the 2004 election), but the math doesn’t really work out for it.
While it is technically possible to create hydrogen from water via electrolysis, it requires such an enormous amount of electricity. It becomes basically a battery at that point (that is you can push a bunch of electricity into it, and store it for later), and it’s among the least efficient batteries around (I think I remember about 10% of electricity in is usable as energy out). The next question is - where are you getting your power? Most of the US is powered by either coal or diesel. And using fossil fuels to generate power so that you can store that power in hydrogen doesn’t feel very efficient tl me.
And in practice, basically all hydrogen is made from fossil fuels. Back then, it was made mostly from natural gas. I don’t know what it’s made from today.
Who knows what the future holds, but unless we find some very efficient way of generating hydrogen, I don’t expect to see it in the main stream. Especially as basically all auto makers finally accepted hybrids, then electric drives.
Yeah so this already exists as a tool and a well-developed technology specifically designed for brazing in fact. The water created by the flame is not a problem for the flux because there’s a flame happening, the water vapor condenses well after the flame has finished up as hot gasses, then had a chance to cool. In fact, any well balanced combustion of propane, acetylene, or any other fuel is going to produce a whole bunch of water. Anyway back on topic…
The Hydroflux is what is is called and it’s a bit of a niche thing but very popular with jewelers who work in spaces that might not allow bottles of compressed gas. It requires several bottles of special liquid to run on but basically it uses electricity to separate water into hydrogen and oxygen, then feeds that back into a torch. I had one for a while but never ended up using it, the largest flame it produces is too small to do any bicycle work with. The flame is certainly hot enough for bronze brazing but the amount of gas it generates, and the maximum tip size, isn’t sufficient. The tips actually look like large syringe tips, more like medical equipment that welding equipment.
I do have an oxygen concentrator though to use with propane.