plate welding / not enough penetration :-(

I am not sure if I am just being parenoid or I have a problem on hand
material :
1/4 plate (mild steel ) "T" welded to 3/16 " cross sectioned (
3"channel)
welding machine is millermatic 175
0.035 solid wire , c25 gas
voltage maxed out at 10
wire speed 6-8
to me it seems it does not provide deep enough penetration in to the
base metal
millers chart reccomends a lesser setting for 1/4 metal.
I like to see deeper penetration , and less bead (deposition.)
any recommendations
fluxcore would be my next step but don't want to deal with the clean
up due to some tight corners.
thanks
Reply to
acrobat-ants
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How about running some 0.030 solid wire instead? Forehand or backhand technique?
Reply to
Thomas Kendrick
thanks for the reply, Do you know if that it will do what I am looking for or you were just guessing ? thinner wire = less current carying capacity ? I will try it,
thanks
Reply to
acrobat-ants
What is your edge prep? If the plate is presently square-edged, you can improve things quite a bit by beveling the edge going into the T.
Reply to
Ecnerwal
If you create a properly shaped 3/16th inch fillet weld all around then you have full strength. This is assuming that you have no penetration deeper than to the corner of the joint. If you REALLY feel that you need more then bevel the ends of the channel. If you need more heat one choice is to reduce the amount of argon in the mix making for a "hotter " of more active shielding gas. Another thought: Are you keeping the arc on the leading edge of the puddle? A relatively fast forehand technique will burn into the root of the joint more effectively. Randy
Reply to
Randy Zimmerman
I was not guessing - thinner wire puts the same amount of power into a smaller area. I was advised to avoid 0.035 wire in my SP100 and stick with the 0.030 for that reason.
Whether it will do what you want is influenced by other factors as well. How about running straight CO2 shielding rather than the mix?
Reply to
Thomas Kendrick
thanks guys a bunch,
I willl try all that was suggested.
let me give some back ground on the situatuion, my paranoya is started after I was talking with an instructor about plate welding, he stated that : (per the AMerican Welding sociaty )on plate welding MIG is not an accepted welding procedure , it should be Stic or TIG, due to HAZ (heat affected zone ) and penetrarion.
My weld beads are closer to 1/4 " in size, nice dome shaped , uniform however the very edge of the weld bead is slightly elevated from the base metal. (kind of looks like a cold bead)
after all that all i could think about is upgrading to a 210A MIG, thinking a 175 may not be enough.
thanks again
Reply to
acrobat-ants
I don't think you are being paranoid. I broke some square-edge T-welds in 1/4" steel plate from my Lincoln 175 in MIG mode and there was almost no penetration. It looked good on the surface. I don't think the MIG mode can put out enough heat to penetrate a T-weld on 1/4" plate. The heat sink on a T-weld is pretty big.
As mentioned, edge preparation may help. Try a bevel to a feather edge on the upper plate. But, of course, you still have the problem of penetrating the bottom plate.
Fluxcore on the other hand, burned in really well, but I understand you comment about cleaning corners. Maybe one of those air-driven needle scalers would help.
Good luck.
Reply to
JohnP
You are pushing that 175 to it's limit with this weld. Bevel your plate end for better root penetration. On a 175 I would stick with 0.030" wire max.
You could try the new 0.030 dualshield wire from harris
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Upgrading to a Millermatic 210 would be a smart move if this weld is going to come up a lot.
Reply to
Ernie Leimkuhler
When I started out with a Lincoln SP100 (110V) and approached thicker metal (like 3/16 mild steel) I went on up to the Miller Bobcat engine-drive. 6010 penetrates very well on mild steel. Rather than upgrade to a 210 amp MIG, why not add an inexpensive DC stick welder and keep the 175. The jump in physical size and weight is fairly substantial going to the 200+ amp MIGs.
Reply to
Thomas Kendrick
I used to hear such drivel twenty years ago. The misuse of GMAW has given it a bad rep that is not deserved. A good example is our Canadian code this year finally recognized spray arc. Hello!! Of course there is no mention of pulse arc which is quickly becoming industry standard. I quote Blodgett from the June Welding Journal: "Codes always lag industry."
Randy
Reply to
Randy Zimmerman
As a further explanation: The AWS only forbids short circuit GMAW.
Also, the Japanese only use GMAW, either with spray arc or with metal cored wires for building bridge steel. No FCAW. No SAW.
Reply to
Rich Jones
So long as you are melting the root, you aren't suposed to get any extra penetration out of a fillet.
If you need the extra weld size for strength, you should bevel the plate first.
Reply to
Rich Jones
If you want good penetratration welds you can preheat after fitup. Preheat to 250F and try again.
Reply to
Lance
thanks all of you for the responces,
I went back to 0.030 solid cleaned the weld area good slight bevel and ran a bead at full power. it still does not look too impressive but could not break it apart wiht a big hammer
I snap a few picture and post a link if some one care to exam.
it seems that a 175 can do it but it would run balls out most of the time.
on a heavy plate like that i just would like to see that succer.... just dig in..... like when I use to run a 6011 rod, now that is penetration.
:-)
thanks to all again. special thanks to Ernie for the additional help, what a nice fella'
Reply to
acrobat-ants
ok , here are some link for the picture if anybody care to see.
this is just a test piece, 3/16" X4" plate welded at the end of a 3" channel
this pic is just top side after the weld. and smashing it with a hammer several times back and forth on top and bottom. as you can see where the weld is the plate stayed perpendicular
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this is the under side not much shows, it did not penetrate through the section of the "C" channel at all.
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this is from the side shows " some" penetration in to the base metal, but it may be because it was at the end of the bead.
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Reply to
acrobat-ants
Your weld is equal legged and relatively flat. There is nothing wrong with the weld. You must start to ask yourself just how much " strength" you need. As you demonstrated the plate did all kinds of bending when you tried to create a failure. I saw an example of a failure at the plate pinned to a large hydraulic cylinder this week. The welds were nothing great but certainly adequate. The cylinder managed to pull out two sections of 3/4 plate on edge. The failure line indicated that it had been working from a crack for ages. The one great thing about mild steel is that it moves all over the place before it finally fails. Randy
Reply to
Randy Zimmerman
acrobat-antsdefinitely ok , here are some link for the picture if anybody care to see.
The weld is definitely stronger than the base metal.
Lack of deep penetration is not, in and of itself, a bad thing. Fillets only need to fully melt the root. Anything beyond that is a bonus.
Reply to
Rich Jones
thanks guys ,
thanks to all that replyed, I have sold my MM175 , and looking to get a MM251 as some of you mentioned in fillet weld it only has to penetrate into the base metal to achive a solid weld. and the machine is able to do it, running .030 wire and even better with 0.025. how ever I do not want to run the welder on setting 10-10 maxed out. so it was time to move -on.
as with most of us , it started as a hobby and developed into a more...
I was thinking that a MM 210 would be sufficient to handle up to 1/4 inch , but wil take a leap and skip over 210 and go for the MM251. so that I don't end up with -sell /buy - in a year or so.
as some of you mentioned miller vs. linoln is like checvy vs. ford.... well I am a big chevy fan and think the miller =chevy , so I will let all the ford guys buy the lincoln. :-)
now I need to get used to that enormous M25 gun.
PS: I must say that I read several news groups and forums, from street/
dirt bike computertweaking, but this place has the best group of people for sure.
Reply to
acrobat-ants
You should be able to get a smaller gun for that machine. Miller is still using Tregaskis guns for most of their smaller (under 300 amp) machines.
Reply to
Ernie Leimkuhler

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