What is this strange orange fluid corroding painted jack posts in basement?

Question

Anyone knows what this blob of orange fluid is? It looks thick and viscous, almost like secretion from some insect.

About 3 -- 4 years ago, I was painting the jack posts in our basement and noticed that a few of them had these fluid droplets surrounded by rust (just like in the picture below) on the surface. I cleaned them up and used the Rust-Oleum Rusty Metal Primer before painting. In a year or so, these began to reappear and now many of the posts have them. The fluid seems to dissolve the paint and cause the steel to rust.

Answer 1

What you see is most certainly rust.

It is a concern because it is compromising a component that is giving major support to that beam above it.

You should have consultations with a few contractors regarding adding support for the beam and removal of the existing column. The cause of the rust needs to be addressed. ( We cannot diagnose that here.) Then a plan to replace the column and prevent future issues must be spelled out. It may be something simple, like just a new column insulated from the concrete. Or something like groundwater under the basement slab.

I do not want to be an alarmist, but this is an issue that must be addressed by professionals and not diagnosed and have repair plans issued from well meaning but underinformed internet folks.

Answer 2

The orange fluid is rusty water. The corrosion started inside the column and has finally eaten through to the column's visible side. Searching the internet for lally column oozing yields many instances very similar to yours. If the column is concrete filled, then I suspect that calcium chloride accelerator and water are causing the corrosion. If the column is hollow, then I suspect that moisture is moving through your foundation, into the post's cavity, and then condensing on the steel's inner surface.

The visible damage looks insufficient to require replacement, where hopefully somebody can rehab the existing columns.