Very thin metal (0.8mm) question

[Welding Bear]

Hi guys, how are you?

Going to move on from 1.5 to 3mm stuff and try again on some 0.8mm (car body)

I've read and hopefully absorbed all the info and will do a bunch of glorified tack welds (with 1 sec pause to allow cool down etc etc)

However, seeing as though my fave subject is penetration (lol) has anyone seen any 0.8mm thick stuff where NOT ENOUGH penetration was achieved?

i'm thinking its going to be more the case of ''if its stuck together, its fine''. but worth asking

 

[norlander]

if you have spare material for a test piece to get the settings right, you can check fusion and penetration. I usually do not have spare stuff to set up on, so for thin stuff I start on a lower setting, if that blobs up,I obviously then tweak upwards to the point where if I went for a continous run I would blow through.
Penetration for me on thin stuff is less of an issue than fusion of the pieces, a lot of my thinner work is battery cases, and I don't want penetration coming through and causing problems with the fit, plus its a git to grind it down on the inside if it does come through.
So I spot up about an inch, then shift to another part of the job, this helps avoid distortion and spreads the heat around the piece and it works for me.

 

[Kent]

No! Indeed you have far greater chance of getting a weak weld on 1mm thin stuff that you got too hot and undercut slightly or changed the metallurgy of the surrounding metal adversely.
On 1mm to do a weak weld the bead should likely fall off if you got too little bite

 

[norlander]

nowts let go yet-and the battery cases get a reet hammering from road shox n vvvvvvibbbbbrattion

 

[Richard.]

Doubt lack of penetration is going to be a concern on .8.