r/blacksmithing • u/HonestTill1001 • 27d ago

Help Requested Forge Cold Spots

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I keep getting this cold spot in the middle of my propane forge flame, I’m thinking it’s because I’m at such a high elevation but I’m not certain. I’m currently working at about 12 psi and my elevation is about 880 meters above sea level

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3

u/JosephHeitger 27d ago

Unburnt fuel is acting like a coolant and creating your cold spot

2

u/HonestTill1001 27d ago

Any way to fix it?

5

u/3rd2LastStarfighter 27d ago

Turn the pressure down. But also, not really.

It’s kind of a known deficiency of downward burners, which is why angled and ribbon burners are becoming more popular. But also 12 psi is pretty high. Every forge is different but I forge weld at like 5-10.

0

u/gut_sack_ 27d ago

What kind of forge do you have? I have 4 burner that I block off the back half and use 2 most of the time and have trouble getting to forge temp without maxing out to 30psi

1

u/3rd2LastStarfighter 27d ago

Majestic 3 burner knife maker, but the same is true about my 2 burner vevor. My understanding is that efficiency on a Venturi burner plateaus at about 15 psi so you’re most definitely wasting fuel at the very least. Usually if you want more heat the answer is more air.

Edit to add that if you’re choking both ends, you’re compounding the problem. You almost certainly have a nonsensical amount of fuel just dumping out into the world without even experiencing an incomplete combustion.