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Mig welding Downhill
Posted: Wed Apr 22, 2015 8:26 am
by admin
Re: Mig welding Downhill
Posted: Wed Apr 22, 2015 5:06 pm
by Superiorwelding
I love the videos where your cut and etch the welds! Besides bends and tensile there is nothing better. As common practice for me and my work we do not weld down on anything over 1/8" because of the LOF shown in your video. It pains me to see those who weld down on structural members, lifting lugs as a prime example. I wonder at times if they know what the weld actually is doing, or not doing for that matter. I had a discussion the other day about vertical down welding g up 3/16" hydraulic tsnks. The response I got was something along the lines of I have been welding for 30 years and have always welded down. My response was that does not make it right. I wish more welders would take the time to do some of this testing on their own. Because of Jody's videos I am a fan of testing and it really opened my eyes.
On another related topic, which is better, fusion or penetration? This will be one of the topics we will discuss at our next AWS Section meeting tomorrow, should be interesting to hear everyone's opinion.
-Jonathan
Re: Mig welding Downhill
Posted: Thu Apr 23, 2015 4:43 am
by b4lamb
When I did my college courses on Mig, Tig and MMA we were advised that only Mig vertical up was acceptable in the UK but in the USA both up or down was accepted. As a result I have not attempted any downhill MIG but it seems a clean joint with thin material can work well downhill. In the video the downhill on 1/4" plate was a little unfair as there was no joint prep and heavy mill scale present. It would be good to have shown what could be achieved downhill with some grinding prep.
I love these videos and like the previous comments do like the ones where Jody does the tests. I always do some macro etch test samples when using a different welding set or a material/joint I have not done for a while. It's how we got our test samples through at college and it's a dead simple and quick thing to do before starting an important job.
We used Nitric acid in college for macro etch of carbon steels but that is not that easy to get hold of so I use ferric chloride, you can get that in pellet form sent through the post. I happen to have it as I sometimes make up copper etched circuit boards as I'm an electronics engineer (well was I'm retired now).
Keep up the good work Jody.
john
Re: Mig welding Downhill
Posted: Mon Apr 27, 2015 7:03 pm
by superclarkey
Interesting video, I always weld uphill on structual stuff but got me thinking that i mainly do rollcages and I always weld downhill on tube like in the video, welds look nice but maybe i should cut a few in half and look fusion/penetration..
Saying that the amount of rollcage tubes I see and cut out of cars that have way too cold welds on is astonishing..