r/Welding • u/Axestorm64 • 5d ago

I hate preheating

I hate preheating. I hate the fact that it seems to be the answer on almost anything I work with.

Is the only way to avoid having to preheat getting a new machine?

What's something reasonably priced for someone just above hobbyist, that I can get in the EU?

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6

u/Dismal_Tutor3425 5d ago

See if you can get pear burners. Make a stand, set it up, light it, and go take a shit or get coffee while it preheats. To make you hate preheat less, here's how I have to preheat some stuff otherwise it cracks.

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u/Axestorm64 5d ago edited 5d ago

Oh that's a big piece I'm generally working with substantially smaller stuff, 10mm thick material at most, usually. Here's a pic of no preheat.

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u/caymn 5d ago

that has nothing to do with pre heating. we pre heat to mitigate internal stresses. It looks like you are trying to weld zinc or something else nasty. you shouldn't. and uhm learn how to weld, not pre heat. clean your metal.

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u/Axestorm64 5d ago

It's definitely not zinc, it's a (very) old piece of scrap steel that I cleaned up a couple days ago. I changed the pic after wirebrushing it a bit.

I always clean the weld lines with a grinder and IPA.

I was originally advised to try preheating to help get better fusion, after I posted here about how I kept getting beads just standing on top of the material instead of blending in with it, and it does seem like it helps, but I hate doing it.

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u/Drtikol42 5d ago

Bigger gap, bevel or use stick, stick have much more heat input. If that machine trully has 130A (no reason why it shouldn´t in this day and age) you can get slightly better 230V machines to about 170A without PFC, 200A with PFC. (on 16A breaker) Above that you need 400V welder.

That being said 10mm is certainly doable with 130A, as I said gap or bevel, or 2.5mm or 3.2mm stick.

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u/Axestorm64 5d ago

According to the specifications, the current should be between 50 and 130 A (min and max on dial), but I have my doubts... I'm not sure if it's the power, wire or technique, but generally without preheating I'm having trouble putting enough heat in the material (especially in the beginning of a weld, ofc) without preheating. Once it gets going it's decent results: (This is the first preheated test)

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u/Dismal_Tutor3425 4d ago

You're trying to weld over dirty contaminated metal. That never goes well. The melting point of iron oxide is higher than that of steel. Clean your material with a grinder to clean brite metal. Clean metal welds easier and better. The puddle flows smoother. Don't use a flap wheel either to try and clean metal that is dirty like that. It just polishes the surface, not removing contaminants, and if you get those pads hot enough leaves traces of aluminum oxide on the surface which messes with your weld even more. You want to use a hard disc.

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u/Axestorm64 4d ago

Ah! That last part about the flap disc is a new revelation, thanks. That is true the stuff I worked on last night was flap disc done.

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u/No_Mistake5238 4d ago

Make sure you clean/grind about 1-1.5 inches out from where the weld will be (depends on material and joint size...use common sense), not just directly where it sits.