Clamps, Magnets or Jigs?

[optionguru]

I recently bought a Clarke 180EN and have put a few pounds of flux core wire through it. Luckily I have a friend who owns a scrap metal yard that keeps giving me cut pieces to practice on. My goal in the near future is to start building a new upper frame for one of my dumping trailers. I'm using 3 inch channel. Sorry for being long winded but here's the question. What's the recommended method for holding steel at a 90 degree angle? Will the heavy magnets be sufficient?

Thank You in advance for any help you all can give me.
Peter

 

[Hitch]

There are various jigs, clamps and magnets available... but youll probably find a tack in one corner, then use a square to true it up, tack the other corner, job done.
If you havnt got an eye for squareness, its a good idea to lean one of the pieces slightly one way, then tack the fcorner furthest away from each other. Doing that will give you some play when checking it for squareness.

 

[optionguru]

Is there a trick to doing a tack weld that can still be bent a little. I've tried doing some quick spot welds and they tend to be too strong/rigid to move. I noticed last night that as I welded some 1/4 inch channel steel to a piece of 1/4 inch plate, the channel seemed to lean back toward me. I think I'll try using the magnet to hold it while I tack weld as you described.

Thanks Again,
Peter

 

[Welderpaul]

Depends how thick the steel is to determin the tack size. For small section i usually use a Bessey jig or a home made jig to hold square before fully welding. For larger section stuff, our saw is pretty accurate, so it is usually good enough just to butt cut ends together and weld.
I would normally weld a couple of tacks say 6mm round which allow a bit of movement for aligning, but also strong enough not to snap. Dont make them too large or you wont get the movement and they are a bugger to weld over without grinding almost flush first.

 

[Hitch]

If you tack it in the right place first, you will find you have plenty of movement. Tack the corners first.

 

[Drains]

My translation of Hitch's pic - leave a wee gap between the two pieces of steel, so you can push the tacked-on piece either way. Sometimes, if you keep the pieces tight, then tack one side (on the right, as shown), the piece (blue) will lean to the right as the tack cools. As you try to beat it back, the tack breaks. With a small gap, this doesn't happen - not the lean to the right, nor the broken tack.

Gap size - under 1/2mm or 1/64"

Hope that's clear ?

 

[Hitch]

It will help if you cut the pieces 1-2mm shorter too.

Got it in one Snowy

 

[Welderpaul]

Got it in one Snowy

Si?

 

[snowcat]

Got it in one Snowy

 

[Hitch]

Err.... got it in one...... Simondrains


Dohhh

 

[Drains]

It's ok, I forget who I am too, sometimes

 

[Welderpaul]

It's ok, I forget who I am too, sometimes

That reminds me. I'm oot tomora neet. (Drinking, not as in closet)

 

[justinveal]

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