Stopping an oxyacetylene weld from popping?

I'm pretty sure that anyone who has oxyacytelene welded has had a weld "pop" when they jab the rod into it or overheat the molten metal. I've been doing some oxyacetylene welding and I'm working on my lap joints. When I was simply laying a straight line on weld across a plate I never made the weld "pop." Now every time I pick up a torch and try a lap joint it goes "POP!" and flings molten metal everywhere. What am I doing wrong? Can anyone shed some light on my problem? Any help is much appreciated!

Comments

[Burf]

That's called backfiring. First turn the gas in the torch off and make sure the connections are tight.
Backfiring can be caused by any of the following: touching the tip against the weld, overheating the tip, incorrect gas pressures, a loose tip or a dirty seat.

[caarntedd]

+1 again.

[seandogue]

(removed by author or community request)

[dla888]

I've got a neutral flame. I'm pretty sure I'm not using an oxidising flame. The weld does not have the bubbles that come from using an oxidising flame.

[the mechanical engineer]

assuming youve set up the torch correctly, just avoid letting the inner cone come in contact with the molten metal. this should solve the problem.

[dla888]

So, am I overheating the molten metal?

[the mechanical engineer]

not quite sure what is going on, all i know is that whenever the inner cone touches the molten metal it pops. happened to me all the time with a cutting torch especially, but i also got it a little when running beads.

[cerberustugowar]

as other people have stated. I would look to make sure your flame is neutral or very slightly carburizing (is that the word i'm looking for?) and like iloveairsoft said. make sure the inner cone doesn't come in contact or get to close to your puddle. Maybe also make sure your line pressures are set correctly ( those numbers I am not sure of) and make sure your tip is clean.