acquired free carboys...possible issue

just got 3 carboys (5 gal) from my father in law, as his deceased father was a hobbist winemaker.

They cleaned up well with straight-A...but I noticed on the exterior, on the bottom, are what appear to be circular cracks.

The bottoms are textured like most carboys, and taking a photo isn't doable (I have no camera good enough).

I can feel these crack lines with my fingernail, and they don't appear to go through all the way.
Each carboy held 2 gallons of cleanser without any leaks and the 3rd held 5 gal. no problem.

so, are these 'stress fractures' forming?
or are these normal due to the way these 30 year old carboys were manufactured?

I had to put off my mead making plans yesterday cuz I didn't want 5 gallons of fermenting must laying on the carpet.

Some of my older carboys have really inticate designs on the bottom that have ridges, and could possibly resemble cracks...but are in fact not cracks.

If in deed they are cracked, I would not recommend using them. No sense in losing a batch if the carboy goes, not to mention the time and energry put into the batch, much less the efforts involved in cleaning up the mess.

An ounce of prevention.....

I'm with Glibbidy. If there is any question at all, do not use them. Carboys are cheap compared to the effort and care and dollars put into a batch.

Sean

yeah, these have the little textured pattern on them, but also these crack-looking rings too.

i have the suspicion they were somehow stacked so the neck/spout was pushing on the center of the bottom, causing wear over the years.

oh well...I wanted a 6.5gal carboy anyways for primary use and the necessary headspace. better safe than sorry.

at least they were free!

When dealing with stuff that can make you very sick or slice open arteries, I follow this mantra.

When in doubt, Throw it Out!