Prepping a joint

[Perry Owens]

I need to join some 25 x 12mm flat bar to some 16mm round mild steel in a "T" configuration for some target hinges I am making. My thoughts are to grind a flat on the round stock and bevel the edges of the flat but I am new to this game and will bow to superior knowledge.
I have an R-Tech 180 on a 16 amp supply so can mig at 180 amps and stick at 160. Do you think this will be up to the job?

Perry

 

[mike os]

The round profile against the flat should be prep enough I would think

 

[Wendelspanswick]

Agree with the above, you could leave a 1mm or bigger root gap as well.

 

[Perry Owens]

Thanks for the advice. One more question, would arc be preferred for this type of job over mig? From what I have read on this forum that would seem to be the case but I'm not sure why or even if that's true.

Perry

 

[norlander]

The R Tech should breeze that, I would go for MMA for that,but,even though I have MMA experience, I don't do it often now, and it takes me a few practice runs to get back into it, and the round to flat could be tricky if you are not up to speed with stick.
Think I would ramp the RTech up in MIG mode and tack the jobs up.Depending on how that went, I might do a root with the MIG, then if pen and toes look ok, I would think about finishing off with more MIG runs, or,finish off the job with MMA.
Normally, I drill the flat to take the bar, and weld the back and grind it flush as well as welding round the bar/flat joint.
16mm is a bit salty tho so I would not be able to do that in this case.

 

[Kent]

Thanks for the advice. One more question, would arc be preferred for this type of job over mig? From what I have read on this forum that would seem to be the case but I'm not sure why or even if that's true.

Perry

yes as mig unless its a big un (which it wont be on 16amp supply) might do it cold! hit the actual hinge with a big enough bullet through and anything could give! Don't fuss about prep much I should just bang them together. Choice of the rod? even a little old 2.5mm 6013 could eat that alive without anything real prep and 100 amps. Out of preference a 3.2mm at 120-130 amp though as that should get it in one run a side. Just practice on similar scrap first if you aint sure.

 

[Perry Owens]

yes as mig unless its a big un (which it wont be on 16amp supply) might do it cold! hit the actual hinge with a big enough bullet through and anything could give! Don't fuss about prep much I should just bang them together. Choice of the rod? even a little old 2.5mm 6013 could eat that alive without anything real prep and 100 amps. Out of preference a 3.2mm at 120-130 amp though as that should get it in one run a side. Just practice on similar scrap first if you aint sure.

The hinges are welded on to the back of a 50 x 50 x 6mm upright and so are shielded from direct impacts but I don't want anything to fall off during a match so will try for MMA. I have some Satinex 3.2mm 6013 rods. Fortunately strength is more important than neatness for this job.
Perry

 

[Kent]

The hinges are welded on to the back of a 50 x 50 x 6mm upright and so are shielded from direct impacts but I don't want anything to fall off during a match so will try for MMA. I have some Satinex 3.2mm 6013 rods. Fortunately strength is more important than neatness for this job.
Perry

what material are you shooting at with what?

 

[Perry Owens]

what material are you shooting at with what?

12mm EN8 plate. These are western action targets and are shot with shotgun, percussion pistol and pistol calibre rifle rounds, lead bullets only and at less than 1000ft/sec. Bullets and balls shatter on impact and the targets move to deflect the splatter downwards.
EN8 is ok for this application for for higher power rifles I use AR500 steel but that's expensive and harder to get cut to size.
Perry

 

[Kent]

12mm EN8 plate. These are western action targets and are shot with shotgun, percussion pistol and pistol calibre rifle rounds, lead bullets only and at less than 1000ft/sec. Bullets and balls shatter on impact and the targets move to deflect the splatter downwards.
EN8 is ok for this application for for higher power rifles I use AR500 steel but that's expensive and harder to get cut to size.
Perry

Yeah I was thinking that way, it surprises many what can be shot clean through with rifles

 

[Perry Owens]

Yeah I was thinking that way, it surprises many what can be shot clean through with rifles

One of our full-bore shooters thought it would be fun to ding our steels with a .243 One round penetrated the 12mm EN8 and two others almost made it through, bulging and cracking the plate. Cost him £30 for a replacement plate.

 

[Bill Edwards]

What thickness Perry?
I've seen a .243 go through 1/4" with no effort, vastly over-sized hole or bend in the plate!

 

[Kent]

1/4 M/S totally no issue for a C/F rifle and lead bullet with a thin copper jacket at 100yards. As above 1/2" plate with the .243 About 1800 ft /lb at muzzle and the least powerful all UK deer species legal rifle. I think what stumps some is how soft lead can be forced through steel no matter how fast its going.