1mm welded to 4mm

[The Buddah]

Hello,

I need a stiff finger to point me in the right direction because below is what i THINK is the way things should go but i'm not 100% sure.

I'll be trying to weld an inner sill to a 4mm box section for the floor project on the disco soon. I was going to run a bead along a 4mm section to check for penetration. Once i feel happy with that i intend to weld the 1mm to the 4mm by running a seam using a eeee motion if that makes sense so that the weld pool spills over onto the 1mm section. I'm considering welding two inch sections at a time alternating from one end to the other until they meet in the middle.

Would i be correct in welding this way?

Thank you.

 

[chunkolini]

Butt or fillet?
Whichever i would have lots of tacks, so that if you blow holes it is easy to repair the damage.
Your description of going eeeeeee makes sense, you could also go ccccccccccc or aaaaaaaahhhhhh! if it goes wrong. Start on the thicker piece and aim to get the weld pool licking at the thinner bit. I find if I look closely I can just see the thinner piece starting to melt, a kind of shiny crescent appears along the leading edge. Try and keep this just under control.
I would do lot of practice pieces before working on anything that matters as 1-4mm is quite a difference.
You also need to watch out for distortion as there wil be a lot of heat going into the workpiece. It can help to do it short sections, eg middle, front end, back end and work your way around.
or something like that.

 

[outofthefire]

I don't know legally whether the sill needs fully welding if its going on 4mm box I doubt its doing a lot structurally so i'd have been inclined to drill a 5mm hole every 50mm and just plug weld it.

If you do want to fully weld it (or it has to be) i'd do it pretty much as Chunkolini says. Though I probably wouldn't do a c or an e i'd just run a straight bead letting the edge of it catch the edge of the thin stuff

 

[The Buddah]

Butt or fillet?
Whichever i would have lots of tacks, so that if you blow holes it is easy to repair the damage.
Your description of going eeeeeee makes sense, you could also go ccccccccccc or aaaaaaaahhhhhh! if it goes wrong. Start on the thicker piece and aim to get the weld pool licking at the thinner bit. I find if I look closely I can just see the thinner piece starting to melt, a kind of shiny crescent appears along the leading edge. Try and keep this just under control.
I would do lot of practice pieces before working on anything that matters as 1-4mm is quite a difference.
You also need to watch out for distortion as there wil be a lot of heat going into the workpiece. It can help to do it short sections, eg middle, front end, back end and work your way around.
or something like that.

I don't know legally whether the sill needs fully welding if its going on 4mm box I doubt its doing a lot structurally so i'd have been inclined to drill a 5mm hole every 50mm and just plug weld it.

If you do want to fully weld it (or it has to be) i'd do it pretty much as Chunkolini says. Though I probably wouldn't do a c or an e i'd just run a straight bead letting the edge of it catch the edge of the thin stuff

I am considering letting the thin inner sill butt up to the box section and over hang the end causing a V shape between the two and welding in the V shape area, how about that?

 

[swedge]

sills only have to be welded the same way it came from factory, but since your replacing the whole lot i dont know

i put 2 complete sills on my nova, fully welded the top part obviously then spot welded the lower part every inch or 2

 

[The Buddah]

I'm not replacing the outer sill only the inner sill. Box section is going where the outer sill would go.

 

[The Buddah]

What i did has been posted on my thread.......floor pan.