welding thick metal to thin sheet ??

[FAAace09]

how do you go about welding thick metal say 2/3mm to 1mm sheet with out blowing holes through the sheet, thanks for help

i dont wana sound thick but say your overlap welding 1mm sheet to 1mm sheet, like a car floor etc, does that make you weld a 2mm weld, or are you still welding a 1mm weld, as my chassis is 2mm thick and im plating it up with 2mm plates were it needs it, if it makes it 4mm weld im screwed as welders only going to about 3mm,

 

[troppo]

Keep your weld bead on the thicker material flicking across to the thinner sheet, focus the heat onto the thicker heat and allow the weld pool to melt into the thinner sheet

 

[Weldinator]

Aim the torch towards the top sheet as your welding along. Experiment on some practice bits to get the right wire speed and power. The 2mm setting should be enough with the right wire speed.

 

[Paul.]

Threads merged

I've merged your 2 threads with the same question, you only need to ask once,

 

[Wozzaaah]

Aim the torch towards the top sheet as your welding along. Experiment on some practice bits to get the right wire speed and power. The 2mm setting should be enough with the right wire speed.

Wha??!!
Not sure where you got that from but looking at the photos you've posted that's probably where you're going wrong.
'aiming the torch towards the top sheet' will result in a weld blobbed along the edge of the sheet with next to zero fusion to the parent metal.

OP, your welder is very low on power, tbh it's not really suitable for chassis repairs but as you seem intent on using it make sure the area to be repaired is very clean, as in shiny, see your face in it clean. That will maximise your chances of getting decent results.
Use 0.8mm wire and full power, bias the weld towards the chassis, travel nice and slowly and allow the weld to flow into the edge of the cover plate.

 

[Weldinator]

Well thats the advice given on the butt welding tutorial here V which i have used on my old 1mm to 1mm lap welds when i first started welding, i am only doing butt welds now>

>Overlap Weld

Overlap welds are far easier to do than butt welds and are a good first step in practicing joining metal with MIG.

In a butt joint you have two sheets of metal of equal thickness. With overlap welding there will be a double thickness on one side of the weld which makes it a lot easier not to blow holes in the joint.

Overlap welds are much like butt welds apart from the torch is angled towards the double thickness (see photo) to direct the heat towards the thicker metal.<

This thread is about the OP problem not mine.

 

[outofthefire]

This thread is about the OP problem not mine.

Yes but you didn't give the op correct advice, so as not to confuse and cause problems for the op it was pointed out.

 

[Wozzaaah]

Just in case any wires are crossed here, the torch is angled towards the joint as the picture in the tutorial shows but the weld pool is biased towards the parent metal as can also be seen in the photo.

This pic should explain what I mean, if you weld as the top one shows, the weld will penetrate nicely into the lower piece and the pool will flow into the edge of the top piece but if you weld as the bottom one shows you'll build weld up along the edge of the top piece but it won't fuse into the lower piece (parent metal) properly.

 

[FAAace09]

nice 1 all

 

[FAAace09]

well wozzzahhh what are you suggesting on welding power to weld 2mm plates to 2mm chassis ?? like to no as so many mixed reviews saying it can then it cant, so im lost at mo really and getting close now to welding stage on my project

 

[Wozzaaah]

Your machine is a bit underpowered but you should just about be able to do it using full power and 0.8mm wire.

 

[Weldinator]

Yes but you didn't give the op correct advice, so as not to confuse and cause problems for the op it was pointed out.

Yes i did, its still aiming wire tip 'angle' towards the top sheet not directly above it, still nothing to do with my welds at all. So you are saying the wire being in the middle of the thickness of the top sheet will still be in the same area ie 1mm all the way along, no one is that precise.

 

[malcolm]

I got the same confusion. Using the word angle rather than aim would sort the confusion out and I think is what was meant.

Works out when you are doing it anyway - if the top sheet burns away you just move a little away from it or angle a little less towards it.

 

[Wozzaaah]

As Malcolm says, 'angle' and 'aim' are not the same so I'm really not sure why you hit the report post button Weldinator, my post gives clear, detailed advice to the OP and anyone else reading, including yourself.
Photos in your threads clearly show weld built up along the edge of patches but with little or no fusion to the parent metal, I'm trying to help the OP not make the same mistakes.
I'd suggest you go back through your own threads and you'll see that amongst other posts, a typical example is when YOU asked

Are curvy cold welds that have still have penetration still good enough for very low strength uses ?

the welds you showed us display all the symptoms I described in this thread.

 

[FAAace09]

1.5 to 1mm help please

hi just in need of a bit of advice in sheet welding as starting my project repairs this week, my bodywork is 1mm and ive got some sheet but its 1.5mm, if i try to weld this to the thinner 1mm will it blow holes through the 1mm, or is it managable, ive also got 0.8mm laying around, but as its thinner than the oem panels i thought the 1.5mm would be better, or would you recommend the 0.8mm instead for ease of welding ??, thank for any comments, im using a clarke 100e mk2, i no its not good welder but plenty enough for panel work

 

[keith19]

Practice tacking a bit of your 0.8mm sheet to your 1.5mm first. this will help get you used to tacking metals of dissimilar thickness. Clamp the metal tightly together.

Start the tack on the 1.5, move across to touch the 0.8 for a moment, then back onto the the 1.5 and trigger off. Do a few and inspect results, and adjust the machine power switches and/or wire speed as required.

When you get good results at this, you will be better placed to do your bodywork using new 1.5mm metal to 1.0mm parent metal. Don't dwell the torch on the parent metal, or it will tend to blow through, especially if there are any pits in the back of the metal.
A quick touch is what it needs, using the 'Thin metal technique' (TMT).

 

[FAAace09]

thanks alot

 

[Wozzaaah]

Threads merged yet again!
Keep track of your threads please, I've lost count of how many duplicates we've had to sort out now.