Minimalist welding skill and equipment acquisition

[Sclass]

I know a guy who does home blacksmithing. He uses charcoal. He collects hardwood from cut down hardwood trees. There are a lot of old almond trees in his neighborhood. He burns the wood in a Dutch oven with an anaerobic pyrolysis trick. Not sure if the details. Then it goes into a forge that uses a gutted hairdryer as an air source. I think he started out with propane and refractory bricks but disliked paying for propane tanks.

It’s a long process but I think that’s where the joy comes from.

ETA - I was thinking about this today and I realized building a charcoal powered forge is minimalist welding. Forge welding is real welding. The first welding done by humans. The fact you can do it by making charcoal out of old chunks of almond tree smoldering in the dirt for a day is minimalism at its best. I can visualize the early blacksmiths cobbling together their forges out of rocks and making an old bellows out of animal skin.

The friend of mine who does this stuff really likes to do things in the cheapest way possible. He uses a hair dryer instead of a bellows because it was cheap from the second hand store. He likes the charcoal because he collects it from “free firewood” piles after tree trimming. Most of his steel and tools are made from demolition rebar and train rails. I think his bricks actually came from a chimney in a house demolition sale. This guy hates spending money.

He doesn’t use propane. 100% charcoal. And it burns hot when blown. Yellow hot.

I’ve teased this guy because he basically starts with low quality steel like rebars and makes them into low quality tools. He doesn’t seem to understand you cannot make a rebar into a samurai sword by heating it up and beating it flat. But, he does almost everything for no money.

Just saying, if you want to invest the time gathering up free stuff you can really do minimalist welding this way.

[Sclass]

Here are my latest TIG brazing practice beads. So far i cannot make pretty welds like the ones on YouTube. It takes a lot of torch time to get to that level. I think my work is sufficiently good to make some custom tooling and do simple repairs to my car parts that are no longer available. I am not going to win any beauty contests but they are sufficiently strong.

Silicon bronze TIG brazing is tricky. Flame brazing is a lot easier to control. There is a very narrow heat window to work in with the TIG torch with bronze that cannot be too hot nor too cold. It’s all interrelated with torch current, gas flow, filler feed rate and travel speed. I tried adjusting a lot of different parameters and this is what I came upon. I still think I’m overheating the base material. But when I back off on the heat the bronze doesn’t flow. So I have to hit it with more heat than I feel is right for brazing.

I’m making things hard on myself by using 16 gauge steel and the cheapest bronze filler I could find. I suspect price makes a difference for filler alloys.

Not good enough to make something like a marketable bike frame. Certainly good enough to make a bike trailer to tow to the farmer’s market.

I am about $600 into this for what it’s worth. I do have a new capability. This is about as minimal as one can go for a TIG setup. Training is almost exclusively YouTube university. I had no experience bronze brazing with an arc process before I got this stuff. It takes a combination of chutzpah and stupidity to dive into this without formal training. It can be done. Move slowly and think things through.

Now I just have to wait till something breaks. If I get my courage up I’ll deal with my window regulator that has a few missing teeth on a gear.



Oooh bronze on steel!

[Sclass]

Poor Man's aluminum weld.

I needed to weld this cracked part for my car. The problem is I bought a very cheap DC TIG welder that can only weld steel. Aluminum requires AC current or the welds just don't form properly with DC. An AC welder is significantly more expensive and I just couldn't spring for one since I never weld aluminum.

But recently I realized most of my car is made of cast aluminum components that are slowly fatiguing apart and wearing away. I realized that I actually need to weld aluminum. And it's a shame because I already bought a steel only welder.

So I was watching weld porn on YouTube and I saw some videos about using a cheap DC TIG welder to weld aluminum without AC (or ultra pure helium). Apparently you can kind of cheat by switching the polarity of the welding electrodes. The arc is unstable and you overheat your tungsten electrode but I learned to compensate for that by making lots of short duration tack welds and letting the torch cool off between tacks.

The welds are ugly. You definitely don't want to put an experimental aircraft together with this reverse polarity trick. But they do fuse the metal together. The cracks got all covered up. I ground down the welds and checked inside and the material is definitely fused together.

Just thought I'd throw this up on the Minimalist Welding Thread. This is poor man's aluminum TIG. Just swap the leads plus to minus.

It works in a pinch or where you don't care about cosmetics.

cracked boss in aluminum casting. About the size of a dime.



finished welds. these aren't aluminum brazing solder that I've discussed before. this is real aluminum fusion welding. basically for free. I used aluminum picture hanging wire as filler.

[Jim]

You can make a scratch start TIG welder out of all an old AC stick buzzbox (free on CL) . The problem with aluminum is you need a high frequency arc stabilizer. You can find these used on Craigslist.

You can also buy a bridge rectifier and make DC Tig with the same AC transformer box setup. If you were so inclined, you can turn the output through a few inductor coils and straighten out the waves, and start stacking dimes (I would love to actually try this sometime, it's pure conjecture).

You can also get a pretty inexpensive aluminum spool gun for a MIG setup, probably find that used to.

Newer inverter machines will run on 120/240/208/480 they just don't care what you feed them with, it's incredible. I can't advise buying a cheap Chinese one, because it's just going to end in the landfill long before it should.

It's possible to make 240 from almost all residential electrical service. If you have an electric range or dryer chances are almost 100% you have 240v. RV hookups I think are often single-phase though.

[Jim]

Oh also, if anyone wants an old thunderbolt 200, and a bunch of old Tig torches, they're free to anyone who wants to pay for shipping (you don't) or pick them up locally.

[Sclass]

Put a sensor port on my motorcycle exhaust today.

No fitting.


Welded up on the bench. The tubing is quite thin and the fitting is thick. Makes for easy blow out. I had to turn my current way down so I ended up burning my stainless steel because I couldn't move fast enough. It is going to look like hell after a few rides so it doesn't need to win beauty contests.


New improved headpipe installed. Now I can mount an exhaust gas sensor.

[Cam]

Looks good Sclass. What process? The finished weld looks very similar to a lawnmower handle repair I did with flux core. Not gorgeous, but not ugly either and definitely strong.

[Sclass]

Hey Cam,

TIG

Yeah I am not getting a job in aerospace with this. I know how it should look but I never have been able to put in the effort to make it look bankable. Especially if I doesn’t fall off and it seals.

This is a lot like sewing. The pattern placement, setup and cutting requires a lot more time than the actual sewing. But we want to get to the stitching because that’s the fun part.

ETA - hey I found this online. This is what it supposed to look like. My results differ significantly.

[Gilberto de Piento]

Looks good! What do you need a sensor on an xr650l (or whatever it is) for?

[Sclass]

It’s an XR400R. I use a wide band lambda sensor to dial in my carburetor adjustments. The factory settings are optimized for emissions. I optimize mine for power, slow speed control and easy starting. It’s kick start only so easy starting is a big deal.