Welding Tips and Tricks

I have to cut 5 openings in a sheet metal cabinet to install ventilation. I have a plasma cutter but worried about heat distortion.
I'm sure that using a plasma would be the quickest. I don't have power shears but not against buying them. Only other option I have is a jigsaw with metal blades. What to do???

Plasma. Use some ally chill blocks around the cut if possible, and keep your post flow turned up. I just did 18ga stainless with a plasma and did not have a bit of distortion.

stefuel wrote: ↑Fri Jan 26, 2024 7:15 am I have to cut 5 openings in a sheet metal cabinet to install ventilation. I have a plasma cutter but worried about heat distortion.
I'm sure that using a plasma would be the quickest. I don't have power shears but not against buying them. Only other option I have is a jigsaw with metal blades. What to do???

how big is the hole? round/square?
the thing i usually do not like about gas/plasma cutting is the cleanup required. i usually prefer drill or saws because it needs minimal cleanup. but that all depends on size etc.

funny thing is a had a small job to do at work and the old boy tells me "you can't drill (large) holes in stainless you will have to gas cut it". i use my hole saws and drill out the holes like it was butter.

The biggest cut would be 22"X 22" square. They will all be fairly large square or rectangular cuts. The edge of the cuts will be exposed. I picked up a "double cut" power shear today. I have some scraps of 16 ga steel left. I'll try all three methods before I make the real cuts. I spent a lot of money having these pieces custom bent up. They are for a project of my own that I'll have to look at every time I walk by it.

Clean plasma cuts are easily obtained. Often, the issue is too low of air pressure. Better to be high on that end and low on the amps.

For cutting stainless square holes, I like to drill the corners as “stops”. It prevents any over-runs with shears or torches.

It didn't take me long to make up my mind. My cuts will have round corners (1-1/2 hole saw in each corner). Made up the first test piece and tried the power shears. End of test. To easy. No problem following a straight line. Zero distortion and very minimal burr. Biggest problem is starting off the edge of the circle. Minimal touch up with a flap disc or grinder, prime and paint. It's a $55.00 Harbor Freight special. It's specified to do 14 ga, but 16 seemed to be struggling. If it last long enough to finish this job, I'll be happy

First picture, old and gnarly. Second picture, still old just not so gnarly

Hmmmm. My pictures didn't take

one more try