rushandy
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| posted on 29/4/14 at 01:34 PM |
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Mig Welding Help :-)
Hi all,
I'm practicing my welding before starting to build the chassis. I'm a complete novice, but still enjoying the practice very much.
I'd be very grateful for the opinions of any mig welders out there, to tell me whether or not they think I'm getting enough penetration.
I've run some test beads down a 1mm sheet of mild steel, photos are below.
Above:
http://i984.photobucket.com/albums/ae321/rushandy/WP_20140425_002.jpg
Below:
http://i984.photobucket.com/albums/ae321/rushandy/WP_20140425_004.jpg
Also, I keep struggling to avoid blow through. I've got my mig set up to the recommended settings for this thickness (lowest power, wire speed
6, Clarke 151TE), but I still blow through about 50% of the time, as per the pics. It's always at the end of the weld bead, I'm guessing
the metal is getting too hot, but would appreciate any advice.
Many thanks,
Andy
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theduck
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| posted on 29/4/14 at 02:07 PM |
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I'm not an expert either but penetration looks good although seem to be blowing through slightly at the ends. maybe try shorter beads.
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cliftyhanger
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| posted on 29/4/14 at 02:17 PM |
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Looks OK to me.
however, that is just a bead on steel. Try joining some steel. It will stop the blowing if an overlap joint, in fact you may need to go up a power
level. Butt welding can be a challenge, but very useful.
i am using the same mig, but gasless (all my welding seems to be outside) and find it good. Just welded some sills on my old Triumph. After repairing
all teh sill strengtheners. I find if it blows holes on the lowest setting, the metal is just too thin. The sills I fitted are probably 1.5mm,
certainly thicker than normal panels. And I used puddle welding, very useful and seems almost foolproof.
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joneh
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| posted on 29/4/14 at 03:32 PM |
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I'd get some box section then practice with that now.
Once you've welded two short pieces together cut through the weld to check penetration. I find very clean metal and a v groves helps tons.
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rushandy
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| posted on 29/4/14 at 03:48 PM |
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Thanks all for the replies.
I have been practicing on box section as well, but I got given these 1mm sheets, and thought I'd use these for demo purposes as it's
easier to just turn them over (rather than having to cut through the steel) to see what the penetration is like. You're right though, I'm
probably best focusing more on the box section then checking that. I'll post back with more pictures when I next have a go.
To avoid the blow through, I think I'm going to try to stop / start the weld, so the metal doesnt get too hot. I guess it's just practice
at the end of the day. No bother, it's good fun :-)
Thanks all,
Andy
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Davedew
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| posted on 29/4/14 at 04:02 PM |
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The blow through as you put it appears to be happening at the ends of the welds?
If so that momentary pause when you stop puts excess local heat into the sheet and blows through. That is also why it looks like you have craters on
the top of the welds. The weld metal is falling through the plate.
Be very careful with start stopping the welds. By doing this if you can get what is known as 'cold lapping'.
The welds might look ok, but they won't be fused along the edges of the weld. This in turn can cause the weld to fail.
HTH
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rushandy
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| posted on 29/4/14 at 05:03 PM |
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quote:
Originally posted by Davedew
The blow through as you put it appears to be happening at the ends of the welds?
If so that momentary pause when you stop puts excess local heat into the sheet and blows through. That is also why it looks like you have craters on
the top of the welds. The weld metal is falling through the plate.
Thanks HTH.
Is there a more generally recognisable term than 'blow through' for what I'm doing?
Any thoughts / tips on how to avoid it? Is it just practise?
Andy
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matt_gsxr
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| posted on 29/4/14 at 05:23 PM |
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more tips than you can shake a stick at on this site too
http://www.mig-welding.co.uk/forum/
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rusty nuts
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| posted on 29/4/14 at 05:52 PM |
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Another vote for the mig welding forum
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rushandy
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| posted on 30/4/14 at 08:59 AM |
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Thanks all, I'll keep trying and then post on that forum if I need any further advice.
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