Mig porosity out of nowhere?

[rustyshakelford]

I'm slowly realizing that having the doors or window in my shop or fan going does make a difference. I didn't know it was so sensitive. Too bad because I want the ventilation for health reasons that I appreciate as I get older.

There a balance to be had with that. You can sometimes turn the gas up a bit to over come the breeze but to much gas cause other issues. I have 5 roll up doors on my shop and atleast two will be opened for ventilation and breeze unless it’s cold out!

Brett

 

[dstig1]

I'm slowly realizing that having the doors or window in my shop or fan going does make a difference. I didn't know it was so sensitive. Too bad because I want the ventilation for health reasons that I appreciate as I get older.

I always MIG in my shop with the doors closed. I set up a big fan behind me pointed towards the doors. Every now and then, I stop, open the doors and blow it all out. Of course i also wear a respirator at all time while welding and grinding. Seems to be a decent compromise.

 

[flyerdan]

What works good is if you can work behind an exhaust fan in the negative pressure zone. That way you're out of the air blast and the fumes just gently drift away without shielding gas disruption.
If you have multiple doors open that create the occasional draft, maybe make a frame with a tarp to act as a windbreak, like we always wound up using those vision screens for.

 

[dragoneggs]

What works good is if you can work behind an exhaust fan in the negative pressure zone. That way you're out of the air blast and the fumes just gently drift away without shielding gas disruption.
If you have multiple doors open that create the occasional draft, maybe make a frame with a tarp to act as a windbreak, like we always wound up using those vision screens for.

One of those fancy translucent welding screens would be nice but I don't weld enough to justify. I am on the look out for a used one that needs a new home though. I do try to stand upwind and block the draft when the project allows it.

 

[arkydog]

One of those fancy translucent welding screens would be nice but I don't weld enough to justify. I am on the look out for a used one that needs a new home though. I do try to stand upwind and block the draft when the project allows it.

did it happen at about th same spot on both spots???? wondering if it could be contamination from the back side. if in doubt, wipe with actone.

 

[Rock Crawler]

did it happen at about th same spot on both spots???? wondering if it could be contamination from the back side. if in doubt, wipe with actone.

Yes, even after grinding back to base material and re-welding that area it came back in that segment. I agree with what your saying, it has to be the paint smoke/fumes from the inside where I could not get the flapper wheel or grinder in good to clean. I tried to get it cleaned as well as I could, and I thought I had enough space between paint and the weld placement area, but it really screwed me up. Sometimes I hate welding. I had a buddy drop an old log splitter that the foot tore off of the beam. So I went and bought a section of 10" mid weight C channel and welded it onto the main beam. The thing had a hydraulic leak for years, and I swear to you... I battles that thing for hours! The hydraulic fluid seemed to have impregnated the pores and no matter what it kept boiling and blowing holes. I used brake cleaner (and waited a good half hour so as to not die) and still got holes. It took 4 or 5 times grinding it out before I got a weld that had minimal porosity, but still was far from perfect. I added a couple gussets to help compensate for **** welds, and it's been a year and it has not broke. Lets hope I do not need to re-visit that repair!

I seldom have nice new clean stuff to fix, all my buddies have nasty, rusty, greasy, oil soaked stuff that they break. Such is life. But at the price of... free... I guess they can not complain!

 

[Relic]

If I get into a project that the Mig can not weld to my liking,I use the old standby, the stick welder.

 

[Mark @ Everlast]

If I get into a project that the Mig can not weld to my liking,I use the old standby, the stick welder.

This. So true.

 

[4570Man]

If I get into a project that the Mig can not weld to my liking,I use the old standby, the stick welder.

Which seems to be a high percentage of what I weld.

 

[Rock Crawler]

I'm a MIG only guy, I've never owned or tried a stick. I saw them as being ugly and barbaric machines that made weeks that you have to beat the flux from, while the MIG lays these pretty and clean welds that you last down and then walk away.

Maybe I need to buy and teach myself stick if your saying that it handles bad conditions better. And maybe it allows for welding upwards where a MIG trips all over it's pecker.