Does anyone here know if MEK (a solvent) would react to cause contamination in aluminum? I usually use ether but i was fooling around at work the other day and all i could find to clean the aluminum was MEK so that's what i used, now it could have been because the piece of aluminum i was welding to was some kind of weird cast alloy that only 1 person in central alberta is certified to weld on (very rare rail cars use this type of metal, i've only ever seen one.) the piece i was playing with was just his old test piece. I got a bead running fairly well but it was still acting weird, in some cases it would really **** up the piece and in others it would run a near perfect bead. depending on how much filler i put in, and when i added the filler to the puddle it would contaminate as well.

just a weird anomaly i observed while wasting time at work the other day..

you think the MEK would have had anything to do with it or just the fact that it is a weird brand of aluminum ?

 

I can't answer your question as far as contaminating the weld. But Methyl Ethyl Keytone (MEK) is a very dangerous solvent. I hope you're using all the necessary precautions. It is one one of the fastest acting carcinogen's known to man.

Clayton

 

yeah, i know, they have all those msds' on the drums, i was wearing gloves.

thanks for replying, i was beginning to think nobody cared to respond to my threads on here. heh

 

You could use mek to clean the weld area but use denatured alcohol afterwards as mek does leave a residue. The mild acids welding shops sell to clean aluminum work pretty well. Sounds like the metal you were welding may have been a different composition than your filler rod.
I certainly don't know everything about welding but I spent 21 years in the airforce as a machinist /welder and have worked on acft my whole life.

 

Aluminum has to be very clean or it will contaminate easily. It may also be because it's that wierd alloy.

LEAVE THE MEK ALONE!!! That is bad ****. Gloves are not enough, you need latex gloves with rubber gloves over the top, a body suit, and a RESPIRATOR. MEK is extremely toxic. We used it to remove stripper when I first joined the Marine Corps. Shortly thereafter we got rid of the baby **** stripper and got a hot tank, specifically because MEK was outlawed to use.

 

they use it in the linings of rail cars, its all over the place at our shop. (in the paint shop anyways)

i know its nasty stuff, they say it gathers in your system over time and may cause allergies and reactions suddenly. i usually stay as far away from that **** as possible but it was the only thing i could find to clean the material off.

anyways i am thinking that the combination of all the factors, cleanliness and filler and weird alloy contributed to my **** welds. i will try again another day when i have free time to drag out the tig and set it up.

 

mek is actually used in some foods. dont know your process you used for cleaning but could have left a film or still had thin layer "floating" around. i dont really know since i've never used it or heard anyone use it like that.

 

I'm no expert with aluminum either, but I know I've contaminated welds by using a solvent brush that someone else had used on carbon steel without my knowledge

just a thought

 

MEK is evil. Dont ever start fires with it. Trust me. I was without eyebrows or eyelashes for a few months.