2mm on to 6mm

[Currymunster]

Hi Guys,
New to this place so a warm hello to all of you.

Own a Defender and bought a replacement crossmember to get through MOT.
Problem is I did not think about how I was going to weld a 2mm chassis onto a 6mm crossmember at right angles - I'm also told that my clarke 90 won't do it but some say it will if I get a good weld pool and lap it on the 2mm.
All advise and techniques would be gratefully appreciated .
Many Thanks
James

 

[octo0072000]

Hi Guys,
New to this place so a warm hello to all of you.

Own a Defender and bought a replacement crossmember to get through MOT.
Problem is I did not think about how I was going to weld a 2mm chassis onto a 6mm crossmember at right angles - I'm also told that my clarke 90 won't do it but some say it will if I get a good weld pool and lap it on the 2mm.
All advise and techniques would be gratefully appreciated .
Many Thanks
James

did you mean a 6 mm cross member think your Clarke would need to be on overtime to weld that

replacement rear cross member on landy normally have plate the fit up and over the chassis of is this a home made one

 

[Currymunster]

did you mean a 6 mm cross member think your Clarke would need to be on overtime to weld that

replacement rear cross member on landy normally have plate the fit up and over the chassis of is this a home made one

Thanks for your quick reply. Yes it is a non genuine one(I'm not gonna say "£%$ made in case the guy that made it is watching (Hee Hee)

Actually it is really well made. It is folded 6mm steel with the tank studs and exhaust hanger plus jack points. But it did not come with the chassis extensions you talk about (******)

I'm still in process of welding chassis upto crossmember so my mind is trying to get ready for the final weld!!! agggghhhhhh!!!!!!

 

[keith19]

Normally when welding such different thicknesses together you would fire up on the 6mm, get it started, then gently ease the pool partially over onto the 2mm as you took it along. You would need about 140 - 150 Amp I'd have thought, although it might be possible with a bit less if carefully done.

The little 90A is likely to lose most of its heat when it hits the 6mm, so you would get a surface weld without much penetration. The 90A is almost at top whack on 2mm anyway. As this is a safety critical item, beg or borrow a bigger m/c.

 

[BrokenBiker]

i agree with keith19, although a good experience welder may be able to manage it with a 90, it will be very difficult to do well.

best to try and get your hands on a 150-160amp m/c to make sure you get enough penetration on the 6mm, otherwise you may end up with a much bigger problem when the welds break off

 

[rich r]

Or arc weld it...

 

[Currymunster]

Thanks for your replies.

This is what happens when you see something you really want.
Rational thinking goes out the window and I did not see the welding complications.

If I had a arc and new how to use it - only ever done mig.

I will have to try and borrow or hire one and eventually save my pennies.

Many thanks

James

 

[octo0072000]

Thanks for your replies.

This is what happens when you see something you really want.
Rational thinking goes out the window and I did not see the welding complications.

If I had a arc and new how to use it - only ever done mig.

I will have to try and borrow or hire one and eventually save my pennies.

Many thanks

James

if you are using it off road remember those welds need to be good or in a snatch recovery all that will be recovered will be the cross member

if you use some 3mm angle iron weld to chassis and then to cross member to spread the load a bit
i would weld cross member on first then weld the angle plates on as well

follow the pictures to see how the extensions fit to chassis
http://forums.lr4x4.com/index.php?showtopic=24884

 

[Currymunster]

if you are using it off road remember those welds need to be good or in a snatch recovery all that will be recovered will be the cross member

if you use some 3mm angle iron weld to chassis and then to cross member to spread the load a bit
i would weld cross member on first then weld the angle plates on as well

follow the pictures to see how the extensions fit to chassis
http://forums.lr4x4.com/index.php?showtopic=24884

Wow - How did you know I was doing a 110 ?
It's a CSW and yes I broke the sender and the spill return.
I looked high and low for a decent how to before I started the job and I did not find that one. Well spotted - you must be a fellow landy man too.

Unfortunatley my chassis was gone further than the anti roll bar mounts and has taken a lot more fabrication than I first thought. X member is on and Ive welded N/s chassis top sides and bottom. O/s side just needs the bottom plate to close it off and the lil bit inside for the tow bar holes which I've had to guess cause the rust made them extinct !!!!

Oh well

Think I may have found a 180 amp to borrow so fingers crossed

 

[The Buddah]

Hello,

Hope you don't mind me jumping in on your thread.

I also would like to weld a thin 1mm sill to a 4mm box section which is going to act as a outer sill for my disco. I have a 185 portamig.
I was considering a few puddle welds along the surfaces to be butted up and try to seam weld the edges.
Would this be correct?
I was thinking of starting on the thicker section and moving the weld pool in a cicular motion toward the thinner sill is this correct?

Cheers.

 

[keith19]

Buddah, how are you doing this? Are you hoping to weld 1mm sheet onto one side of the 6mm box section?
Plug welding it with a soft arc should be possible; do some practice on similar size scrap first. If you go for butt welding the top edges of the two sections together as well, you might be better to drop the 1mm sheet a few mm, so the 6mm box thus exposed takes most of the heat. And use the thin metal technique.

We used to fold over and spot or plug weld for preference where possible, but there are always places where it isn't possible.

 

[The Buddah]

Buddah, how are you doing this? Are you hoping to weld 1mm sheet onto one side of the 6mm box section?
Plug welding it with a soft arc should be possible; do some practice on similar size scrap first. If you go for butt welding the top edges of the two sections together as well, you might be better to drop the 1mm sheet a few mm, so the 6mm box thus exposed takes most of the heat. And use the thin metal technique.

We used to fold over and spot or plug weld for preference where possible, but there are always places where it isn't possible.

Hi Keith,

Thank you for helping. I'll look for the thin metal technique.

Yes but it's 4mm box and 1mm sill.
I was going to drill a 10/15mm hole in the 1mm sill then puddle weld starting in the middle of the drilled hole working outwards.

The holes were going to be a couple of inches apart vertically and also 6 inches or so horizontally. The edges of the sill and box section were going to be seam welded with the weld starting on the thicker side and creeping over to the thinner 1mm sill.

I also need to puddle weld the floor of the car to the top of the box section where i can't get access once the sill/box section is in place, I'll seam weld any joining components that are visible.

I have a couple of panels to make up before move on with that though.

 

[keith19]

You might do better with smaller plug welds at closer intervals. Usually plugs are about 6 - 10 mm across, with 8mm as the usual mean average.

2 inches vertically apart sounds about max distance, 6 inches horizontally apart sounds a bit far; you would have to be careful of the sheet not 'lifting' between welds at that distance. Starting at one end and flattening out carefully as you move along should deal with this, or start in the middle and work outwards, flattening as you go. Personally I'd use 8mm plugs at 50mm (2") apart.

As you say, when you join the edges of box and sill, favour the thicker metal, moving very gently over to the thin and back again.
Where edges join we have to be careful of not blowing the thinner one away. So one technique is to drop the thin edge a little, so the thicker edge takes the initial arc heat. Use the thin metal tacking technique, eventually blending the tacks together.

The diagram below shows this for a vertical 1mm sheet application to 6mm box, but the principle is the same if you are working horizontally. If you are a bit experienced, you can get away with No1 by just touching the top edge of the sheet as you move along, but No2 gives a generally easier job, and cleans up nicely to a curved edge. Green arrows just indicate plug welds to a vertical surface.

 

[Currymunster]

Hello everyone.
Finally borrowed a 150 amp and got started today.
Its green with mig 160 written on _ No idea what make it is as it doesn't have it written anywhere??

Wow - i could feel the power compared to my Clarke 90pro

off to a great start on number 5 setting(max) weld drips off on vertical and upside down(dripped into tip(AAAGGHHH)). Had a problem with burn back into tip and had to keep clean and freeing off(which was fun as never used a ?Eurotorch? Left hand thread - splatted a lot then was good (assume thats just outside wind for you)

Thanks for all your help and thank god its done - A bit messy but done!!!

 

[Weldinator]

Sorry to hijack this thread but when welding 2mm to 6mm on a car chassis, would it be a good idea to not remove the cars sealant behind the welding areas, so then you get the penetration using high power without burning through the 2mm too easily ?

 

[keith19]

You'd probably get away with leaving the sealant on the back of the 6mm, if it's only getting 2mm tacked to it, or in short runs. But it would still smoke a bit, and might burn unless you spaced the welds well apart.
Sealant tends to act as a heat insulator before it burns, which means the area would hold its heat for a bit longer than if it was clean steel.

 

[pedrobedro]

weld drips off on vertical and upside down(dripped into tip(AAAGGHHH)). Had a problem with burn back into tip and had to keep clean and freeing off(which was fun as never used a ?Eurotorch? Left hand thread - splatted a lot then was good (assume thats just outside wind for you)

Too many amps if it's balling up and running back, turn the power down or weld faster. Euro gas shroud is not threaded it is on a spring which turns the same way (right) for on or off and the tips are not left hand thread on any I've used. Don't knacker your mate's welder or he won't lend it to you again.