Blowing holes

I am in the process of cuting out rust and welding in new metal on my 64F100. I either have bbs or blow holes in the old metal. I'm using an Eastwood Mig, 23k wire and gas/ Please tell me what I'm doing wrong.

 

There s a lot of stuff it could be.
How about you tell us what's been done to set machine and prep the metal

 

Cut out more to get to thicker less rusted metal.

 

Proper term is "glory hole"

 

More info ... or or OR I'll put this in the stupid questions thread.

There are 27,000 welding books out there, I could write one just for you but I ain't going to do that.

 

Glory hole ??
Isn't that where someone is on one side of the hole and you .....
Oooops wrong board. Oh yea blowing holes.

 

Are you trying to run a bead? You want to do a series of tack welds rather than try to run a bead.

 

and lots of practice....

 

He said he was blowing through the old metal, either he still is not out to good thick metal or he is useing 14 or 16 gauge for repair.

 

You are a better mind reader than me. I ain't even
going to guess

 

without seeing what you are doing it is difficult to offer any remedy.

blowing holes could mean you need to turn down the heat some.... either that or you need to hit the trigger lighter..just a tap. just enough to quickly melt the two sides together.

I assume you are butt welding. how are your gaps? try to get no thicker than the wire.

practice on some scrap. clean metal, good gaps, good ground. all that stuff. try different heat/wire speed and try different ways to hit the trigger.

my neighbor has been building X-ray equipment for 30 years. builds all these crazy looking machines out of steel tubing. been welding way longer than I have. a kid in the "hood" asked him to weld together a sheetmetal muffler he made for his 2 stroke powered bicycle. he blew it all full of holes and gave up, kid brought it to me and it was easy squeezy since I have a lot of practice. so there is some mysterious technique to it that is hard to explain over the interweb.

 

Turn on the gas, and switch the polarity. Do the opposite for the drivers side.

 

Ha Ha Ha..

 

I'm welding 18 gauge metal to the original metal. When I turn the heat down it just puts out little bbs that are hard to grind down. I am just trying to spot weld it, but I think what 49ratfink posted will help. I need to reduce the gap. If I cut out more metal I will have to cut the whole roof. Do I need to spot it all the way around? The spots are every half inch or so now. Thanks

 

Slow down. Cut down on the power and cut way down on the wire feed. Practice on some scraps. You want to get good penetration and a small bead. Learn to lay a nice bead slow, when it feels too slow increase power and wire speed a bit. Blowing thru means too much power , gobby chewing gum welds sitting on the surface means too fast wire feed.

 

I sanded the old paint off, do I need to do more?

 

You need good shiny metal, make sure there are no small rust pits.
You need to make sure your ground clamp is also on good shiny metal.
18 gauge is probably a bit thicker than the cab metal was when it was new.
Try setting you welder to the recommended specs for between 22 and 18,
Aim your stinger towards the thicker metal and just try and do small spot welds toward the old cab metal.
It sometimes takes lots of patience....

 

There ya go,solid answer.

 

Take some scrap, duplicate your joint and play with the settings.
Getting a good weld here will eliminate or expose problems with the parent metal of the cab.
Master that first.

Does your welder adjustments have detents or an infinite dial.
What gas ?

 

Also,use a copper strip/peice behind your weld/spot which will help alot with the blowthru.Make sure you hold it against the area you are trying to weld.
Turn your wire speed and amps down until you get to colder weld then chase the settings up until you get it right.Like some are saying,use a scrap peice first the same as you want to weld for setup.Good luck.