What Causes A Blowhole

[Scott NC]

  I have a old Lincoln Tombstone welding machine and everytime I lay a bead, at the end of it is a big hole you could stick the tip of a ink pen in.  I only use 6011 at the proper amperage and have been for years and never had this problem.  Out of neccesity, I am running it off a Craftsman generator and wonder if for some wierd reason this is causing it.  I ground out the bead and the hole goes all the way to the joint.  It's driving me nuts.  Also, I will include a photo of the project that I am working on.  It is a flower I am making.  You can see the glob welds where I tried chasing/covering the hole up on the leaf stems.  While I'm at it, could those leaf stems be forge welded on there?  I have only made a few successful forge weldings on 1/2 bar and don't know about tiny stuff.

  I've been mig and stick welding for a long time but never had such a problem.  

[LarryFahnoe]

I'm more familiar with TIG, and a pinhole at the end of a bead with that process can be a sign of too much heat. Resolution (for me at least) is to back off a bit as you come to the end of the bead. Sometimes I also incorporate a bit of a swirling motion with backing off the heat. I wonder if that would be possible with your welder?

--Larry

[Scott NC]

Larry, I have tried pulling the rod out slowly, jamming it in real quick, swirling the puddle around, back and forth, you name it.  There's a blasted hole.   I use new rod.  I have only tig welded a few times on my friends machine.  I like the precision.

[Frosty]

Are you running it AC or DCEP? (Yeah, I looked it up I'm WAY out of practice and don't remember settings like when I burned rod.)

The way I dealt with the end pit (jr high school term I've never stopped using). I slowed as I neared the end to make a little heavy bead, then welded over the end, reversed back over the thick bead and pushed it into the puddle with the arc's shield column.  All of that takes a long half second, a person who doesn't know what's going on will never notice.

You may have done it differently but once you find one trick that works it will come right back.

Frosty The Lucky.

[Scott NC]

  Sorry, AC.  I took it over to my sisters last night and plugged it in and it ran fine, no holes....  I should have done that in the first place.  I just left it there.  I'm going to go get a wire welder next week, I am tired of stick welding anyway.

[Irondragon Forge ClayWorks]

Sounds like the generator is the problem. Do you have a plug in for it in the shop? My old Tombstone welder runs fine on commercial power but when I tried to use it with my generator, I also got end pits.

I can't control the wind, all I can do is adjust my sail’s.
Semper Paratus

 

[Scott NC]

  I have no plug in for the time being.  Thanks for confirming my suspicions...  It's been a great welder and ran fine for 20 some years and then started this irritating behavior.  I think I paid $60 for it used, so it was a good investment and it can enjoy being retired until I get some wiring put in and want use it again.....  I wont miss that loud generator either.

[Bud in PA]

I have my Tombstone plugged into my 220 volt line and have no trouble. If you get a cheap flux core welder make sure you get a C clamp to tighten your feed wheels. It will work better when you get some wear on your feed wheels.

[Scott NC]

  Thanks Bud but I'd rather a sharp stick in the eye than a cheap flux core welder.  If it comes to that I will remember the tip.  Might be blind in one eye, though.

[Scott NC]

  I should say that I have had one a friend gave me years ago and it was a frustrating POS.  Maybe they have improved in quality, I don't know.  I don't mean to sound so negative on them.