[ant_8u]

I'm fitting some small box sections to my chassis, but they don't fit very well

I've spent the day improving the fitment, but I've still got a gap down one side which requires welding

My question is how much gap if any is acceptable whilst mig welding?

The gap is around 2mm
Can I weld this, fill it another way, or will I need to do something more involving?

The edge in question doesn't need any strength

I'll post a picture in a second

[ant_8u]

The vertical face has a gap of around 2mm
What should I do about this?

Thanks

[richard stewart 3rd]

Hi
Is it possible to use a C clamp & draw it in a little? I've filled much larger gaps then what you have there, but had ceramic behind the piece & the metal was much heaver.
Rich

[speedbump]

Welding air is an art form. If I was attempting it, I would use a piece of 1/8(3mm?) gas or TIG rod tacked into the gap top and bottom to use as filler rod.
Then start the arc on the frame side which is larger and will handle more heat, and weave the arc across the filler rod to the boxing plate while moving down the weld area. Trying to do vertical with a MIG is touchy also. Your best result will probably be by making about two to three weaves down then stop for a few seconds to let the metal cool, continue another two to three, let cool, etc. If you let the puddle get too hot it will run down beyond the weld puddle and there will be zero penetration and a big mess. Having an auto darkening helmet helps a lot on this as you can pause to cool without ever moving the gun and start again in the exact place you left off. Always start and finish your weave on the thickest metal and have the MIG gun pointing up toward the weld so the wire travel helps keep the weld puddle from falling downhill. This method will not give optimum strength but it will work pretty well with a little practice......and some grinding to make it pretty.

[boatbob2]

Hi X2 on what speedbump said,BUT,i would heat the vertical piece,and hammer it in closer,take your time,,,

[matts37chev]

you could make a small cut on the top and bottom so it will fold in tighter
then weld the cuts

[ant_8u]

Thanks guys

I'll try making a couple of cuts in the top and bottom, apply a little heat, and if need be ill try using some welding rod too

Whilst ive been practicing my welding on scrap metal, This'll be the first part I've actually welded to my car.....I can't believe how badly the pieces fit, I'm only a beginner so I work extremely slowly, but it's taken me all day to get the fit as good/bad as it is so far

Let's see what I can get done tomorrow

[ant_8u]

Just checked the online store and my local shop has welding rods in the following (metric, sorry) sizes......

1.6mm, 2.0mm, 2.5mm, 3.2mm

In addition to these chassis sections I'll also need to play with my door gaps, but that won't happen for a little while yet

Should I buy the thickest rods and just gring them down where needed whilst doing the door gaps later on, or should I buy a mixed selection of each of them?

Thanks again guys


EDIT; imperial sizes are approx....
0.063", 0.079", 0.098", 0.126"

[Old Fool]

Originally Posted by ant_8u

Just checked the online store and my local shop has welding rods in the following (metric, sorry) sizes......

1.6mm, 2.0mm, 2.5mm, 3.2mm

In addition to these chassis sections I'll also need to play with my door gaps, but that won't happen for a little while yet

Should I buy the thickest rods and just gring them down where needed whilst doing the door gaps later on, or should I buy a mixed selection of each of them?

Thanks again guys


EDIT; imperial sizes are approx....
0.063", 0.079", 0.098", 0.126"

I'd get a small selection of all sizes, its not very spendy and you will find plenty of uses for it. I assume you are talking copper coated steel.

You didnt mention what type of welding you are going to do. Gas,mig,tig,stick?

Since you are new to welding the better the fit the easier it will be to weld up and the better it will look.

The fitup you have could easily be welded with a tig with .035 wire by an experianced welder. A bit of a gap but definately fillable.

Putting in a backer rod will work, but if appearance is important the backer rod look ugly imho.

[ant_8u]

I'll be MIG welding the parts

Here's a link to the shop I'll be going to in the morning

http://www.machinemart.co.uk/shop/se...=SRC-AUTO-weld

Are these rods the correct ones or not?

I'm not anywhere near being considered anything other than a beginner so i'd say fitment (for ease) is more important to me than it would perhaps be to others

[ant_8u]

Yep, got it

I've got the auto darkening helmet like he suggested, I just need to get my technique right

I think he was suggesting I do that whilst incorporating a welding rod too?

[Old Fool]

If you are going to use MIG and get a bit better fitment you should have no trouble running a bead vert up.
Keep a quick weave across the gap and pause for a tad to let the puddle form on the edge, move back across and let the puddle form again, the two puddles should almost melt in to each other and the metal you deposit on the way across bridges between the two edge puddles.

Put good tacks or full welds on the top and bottom before welding up the vert so it doesn't move around on you.

At any hint of it getting out of control, stop. Let it cool down and start again.

Make a few test passes on a scrap mock up and you will get the feel pretty quickly.

[Jake_Dragon]

I would start at the top and tack then smack the gap shut with a hammer. Once everything is tight just clean up the tacks then weld.

[ant_8u]

Thank you OldFool

I'll be welding the top and bottom first, once i've had another go at improving fitment and clamped everything into place

I was just about to ask, should I start from the bottom when doing the vertical weld, but you just answered that for me

[ant_8u]

Thanks Jake

I'd have thought starting at the bottom would have given slightly better control of the puddle?

What do you think?