joint type + amperage starting point question

admin

Is there an official name for the type of joint where you lay a piece of rod, tubing, or pipe down on a flat plate and weld it to the plate with beads running in the axial direction (i.e. along the length of the rod/tubing/pipe)?I'm making a T-bolt out of a 1/2-13 x 1" hex bolt and a length of 1/2" dia x 2.5" L rod (both stainless) (see attached drawing) .  Going to ball mill a shallow trough in the head of the bolt for the rod to sit in.  The bolt head is .312 thick (nominally) and the rod is 1/2" diameter as stated earlier.Considering that I don't have a TIG machine capable of 300+ amps, the 1 amp per mil rule is out the window.  Given the geometry of the joint and the short length of the beads (they're only going to be about 0.7" long each), what would be a good ballpark current to run at?  My air-cooled torch is only rated to 150 A.  Should I just crank it up to 150 and lay it in there fast to try to avoid heating up the parts too much?Should the tacks be autogenous or with filler?  Would it help (or hurt) to do an autogenous "root" pass and then do a second pass with filler?  Or just do a single pass with filler from the get-go?  Given the joint geometry, I definitely want the finished weld to have filler - just not sure of the best path between the fitted parts and that goal.This is just a one-off for personal use and will only see hand tightening (it rides in a slot and locks the front/back adjustment of a lawn mower seat), so it doesn't need to be x-ray quality or optimized for low cost production.   Attached Images
Reply:Yes. A flared v-groove if I remember correctly.
Reply:Yahtzee!  Thanks!Any thoughts on what current and the use of filler?
Reply:Derp - this came up last year, but forgot about it:http://weldingweb.com/vbb/showthread.php?t=61080#9Same picture and everything.  In my defense, it was for a single-sided application in that post.  Last edited by dbotos; 08-09-2012 at 02:10 PM.
Reply:I was itching to weld, so I went ahead and did this one up with the following approach/rationale:-autogenous tacks, one per side: figured there'd be less bump to go over when laying a bead-150 amps: the rod and bolt head were decently thick, plus I've read it can be advantageous to lay it in "hot and fast", which can actually result in less total heat into the part since you're not sitting there spending more time at a slightly lower current-beads with filler: figured it needs to go in there anyway, might as well put it in from the get-go, plus the tacks had some undercutting, which I wanted to avoid in the finished productThe 150 amps may have been a little high (I got a bit of undercutting here and there, but it could have just been me going too slow with the torch or not adding filler fast enough) and I definitely need to work on my beads (looks more like a pile of change than a stack of dimes).  Originally, I was just going to lay a bead down each side of the rod, but I decided to go up underneath it on both ends too.  One of these days, I'm going to have to make a positioner for little stuff like this.I installed it on the mower with three 1/2" USS washers underneath (total thickness of 0.280") and it just clears the adjacent shoulder bolt.  Planning to make a nice thick (0.312") washer for it out of SS, which will give it another 1/32" of clearance and keep both parts galvanically similar.Any comments or advice are welcome.Thanks,David Attached Images
Reply:That works. For what it's worth, depending on exactly which "150 amp" air cooled torch you have, it can go well above 150 amps. The Weldcraft WP 17 torches are rated at 60% duty cycle at 150 amps. I've run 200 amps thru one for short periods of time before the torch became too hot to hold. The CK torches are rated at 150 amps 100% duty cycle, so they'll take even more heat. I find if you use light weight tig gloves, chances you'll melt an air cooled torch are pretty slim since it will become too hot to hold well before it melts assuming you aren't trying to blast 400 amps thru it in one shot. I wouldn't recommend using heavy gloves and seeing just how high you can weld with one, but most home size machines won't go over 200 amps usually anyways..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Originally Posted by fronty_78Yes. A flared v-groove if I remember correctly.
Reply:I made the super-thick washer today and actually did a little mowing after installing it.  Everything held tight.  Now I just need to modify that goofy shoulder bolt that has too much gap between the bracket and the underside of its head.  And maybe blast and powdercoat that bracket... Attached Images
Reply:Beefiest T handle I've ever seen!  That badboy will outlast your chair!  This might help,http://www.metallicfusion.com/symbol...efinitions.htmLast edited by mb_welder; 08-14-2012 at 05:24 AM.
Reply:Originally Posted by dbotosYahtzee!  Thanks!Any thoughts on what current and the use of filler?
Reply:Originally Posted by BlueArcQuestion for you guys: section 2: "other side" weld detail. Seeing as it's not on the bevel joint, and just a butt joint, why does it still carry the bevel symbol?