mig and flux core tips and techniques, equipment, filler metal
perlmonkey
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Just starting out with MIG and I have a question about welding up a rectangular frame out of 2" square tubing. I've seen guys on youtube tacking up the entire frame using jigs and whatnot, then welding the entire joint after all is tacked. I'm wondering if it is best to do the same... tack everything, then weld it up or just tack one joint at a time and fully weld it.
My concern is keeping everything as square as possible. I've got everything prepped and cleaned, but wanted a little advice before I go at it (weather permitting).
Thanks all!
West Baden Iron
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perlmonkey wrote:Just starting out with MIG and I have a question about welding up a rectangular frame out of 2" square tubing. I've seen guys on youtube tacking up the entire frame using jigs and whatnot, then welding the entire joint after all is tacked. I'm wondering if it is best to do the same... tack everything, then weld it up or just tack one joint at a time and fully weld it.
My concern is keeping everything as square as possible. I've got everything prepped and cleaned, but wanted a little advice before I go at it (weather permitting).
Thanks all!
I would definitely recommend to tack everything then weld it up. Even then, don't pour the heat too much to one joint. Ideally, you want to keep a lot of heat in one area to a minimum and spread it out as much as you practically can. If you fully weld each joint, you will really draw the metal and be out of square in a hurry. I still struggle a bit in fabbing up pieces with not overdoing the heat in one area. Plus it is much easier to cut off a tack weld if a mistake is made rather than a fully welded joint.

Thanks,

Jason
Lincoln Square Wave 175 Tig/Stick Miller Spectrum 375 Plasma
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I second tacking first. I never weld anything out before I have it tacked and braced up. I also tack hotter than I plan on welding. This keeps me from shitting myself when i'm underneath a 1/2" plate and I dont hear tacks break.
Alexa
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perlmonkey wrote:Just starting out with MIG and I have a question about welding up a rectangular frame out of 2" square tubing. I've seen guys on youtube tacking up the entire frame using jigs and whatnot, then welding the entire joint after all is tacked. I'm wondering if it is best to do the same... tack everything, then weld it up or just tack one joint at a time and fully weld it.
My concern is keeping everything as square as possible. I've got everything prepped and cleaned, but wanted a little advice before I go at it (weather permitting).
Thanks all!
=========
Perlmonkey.

Assuming that these welds are to be partial penetrated, you may consider:
- set all your supports upon which you will be working to be within the same plane to insure flatness.
- make note of the different lengths of the pieces to be welded and compensate during tack-up.
- control the diagonal distances as you tack.
- put a button of mig in the middle of the four external vertical edges of the joints.
- check the diagonals.
- a button in the middle of the four upper (topside) flat edges of the joints.
- if accessible, put a button in the middle fo the four lower (underside) flat edges of the joints. if not flip the frame.
- a button in the top and bottom external corners of all joints.
- a button in the top and bottom internal corners of all joints.
- check the diagonals.
- weld all four external vertical edges if possible vertical down.
- weld the upper (topside) of each joint, starting at the internal corner and welding towards the external corner.
- flip workpiece, and repeat.
- weld the internal corners, if possible vertical down and as light as possible.

Note: if you need to weld multiple frames you may want to also utilize a jig.
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Alexa's advice is spot-on!

I'm guessing he's (she's?) welded a handrail or two, or other similar frames.

The sequence given will minimize the ability of "draw" to pull your frame out of square.

You'll want to tack as much of the structure together as possible before welding, so each component helps hold the rest in alignment when welding. Sometimes, a component or two must be left out to access a weld, in which case you should see if you can use some temporary bridging as close to that component's location as possible.

Any time you weld parts at an angle, the tendency of the metal is to draw toward the inside corner, and this can be allowed for in the fitment when welding otherwise unsupported material. An instinct for this will come with time; The easy way now is to try it on scrap of the same material and measure.

Steve S
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Interesting.

"Alexa" is listed as a "bot" when online.

That implies a search engine. I was pretty sure I was responding to a human.

Either a human "enrolled" the bot, or something just passed a Turing test.
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Hey

Its like Terminator mate, the "bots" get smarter and smarter.

Mick
donaldsanchez
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Track everything and then weld it up. It will make the weld perfect rather than the opposite.

_______________
Spot welding tips
cptjackm
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Five stars ★★★★★ Alexa.
Thanks I saved that:


"Assuming that these welds are to be partial penetrated, you may consider:
- set all your supports upon which you will be working to be within the same plane to insure flatness.
- make note of the different lengths of the pieces to be welded and compensate during tack-up.
- control the diagonal distances as you tack.
- put a button of mig in the middle of the four external vertical edges of the joints.
- check the diagonals.
- a button in the middle of the four upper (topside) flat edges of the joints.
- if accessible, put a button in the middle fo the four lower (underside) flat edges of the joints. if not flip the frame.
- a button in the top and bottom external corners of all joints.
- a button in the top and bottom internal corners of all joints.
- check the diagonals.
- weld all four external vertical edges if possible vertical down.
- weld the upper (topside) of each joint, starting at the internal corner and welding towards the external corner.
- flip workpiece, and repeat.
- weld the internal corners, if possible vertical down and as light as possible.

Note: if you need to weld multiple frames you may want to also utilize a jig."

Jack
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