[rjd1234]

I'm getting ready to weld a piece that will be part of fruit press. I have never welded this thick of stainless (304) before. I had the pieces cut with interlocking tabs and the strength will come from the structure, not the welds. The welds will be to keep everything in place and be blended smooth to remove corners and make the surface food safe.

I'm thinking tack, root, then cap (walking the cup). I think this will be a good opportunity to practice walking the cup... Since it will all be blended anyway.

Can anyone share guidance on sequence to reduce distortion? Settings for root and cap?

PXL_20231217_005930555.MP.jpg (4.45 MiB) Viewed 12222 times

[tweake]

i can't help with settings, that size is out of my league.
however a lot of gear i see, and use, often has minimal welding as the design carries the load no the weld. so often its just bare minimum weld, no filler used. or just enough filler to stop undercut.
all depends on the design and loads the welds will have to take.

[Coldman]

The way I would do it is:
- find a way to clamp down all four quadrants at the same time without restricting access for the tig torch.
- set 180amps and use 2.4mm wire
- use a large gas lense cup, min #10
- light up in the corner, peddle to the metal, and go fast.
- go to the opposite side of the base plate and repeat
- skip around the quadrants till complete.
- consider 1" stitches to reduce total heat input
- release clamps only after the base plate has cooled to ambient.

[rjd1234]

This is great. Thank you.

If I do 1 inch stitch welds, should I let the piece cool in between? Or try to keep it hot until the piece is welded completely?

Would you recommend walking the cup?

[rjd1234]

One more question... Would you recommend using pulse?

[Coldman]

Up to you whether you walk the cup. I'd just lay wire it. At 180 amps you'll be going very fast if you're a cup walker.
Definitely not an application for pulse.

[cj737]

I too would weld in “quadrants” but I’d start in the middle with tacks, then out to the ends, tack, alternating sides and moving around. Think about the weld you just put down, where will it pull against? Weld there next to balance the stress.

180 amps seems high to me, I’d be lower and when stitching I’d be surprised if you’re above 130… That material is going to suck up the heat and be very hot reducing the need for amperage as you go. Definitely run a long post flow to avoid sugaring where the tabs pass thru the plate, unless you’re welding from the top side?

Another trick is to tack the round plate (that is shown as the top in your pictures) to another piece or your table. Weld the structure to it. Let cool. Then cut the top loose. Welding it down to a larger surface while you weld to it will prevent it from warping. 6-8 small tacks around the circumference will do it.

[rjd1234]

CJ737, yes, I will be welding the tabs as well. You can see the top tabs on the top, but there are also tabs in the bottom plate as well. Everything will be welded and blended so it looks like one piece... It will be used to make juice.

I have asked the laser cutting shop for some scrap to practice on... That will give me an opportunity to play with different amperages. I should have thought of that before.

I was planning to clamp the piece down to table for welding... Hadn't thought of tacking the piece to the table.

How much should I let the piece cool between stich welds?

[cj737]

If you weld the plates down, then you don’t have to allow much cooling between stitches. But let it cool fully before cutting the tacks loose.

[rjd1234]

Follow up on this project. I tested settings on some scrap and ended up with

140 Amp, DCEN
1 S Preflow, 6 S postflow
#13 Gas Lens

I stitched welded and jumped around from quadrant to quadrant until it was finished. I used compressed air to cool the welds quickly until I could touch it with a bare hand before moving on. The image shows the piece before I ground down and polished the corners smooth.

[tweake]

nice one