how to dissolve borax crystals

Hi, I dissolved some borax in a canning jar to use in the wash, did not use all of , so the borax made crystals formed on the bottom of the jar. If I had only used an old mayo jar I would just throw it out, but I hate to lose a good wide mouth canning jar. I tried hot water, vingar, and baking soda- each separately  - so far nothing has worked. Any chemists out there know  what else I can try?

Borax crust left in glassware is notoriously a pain to remove. The usual procedure in chemistry was HOT water and elbow grease scrubbing. I'd love to know an easier way as well. It has been some time sense I was in a lab but you never know.

I wonder if it interacted with some minerals in the water.  Which... scratching the back of my brain here to remember... might make it into a salt?  Which reminds me of limescale.

My next step would be to try a stronger acid like cleaning vinegar or a citric acid solution.  

(but I might be wrong, it's a long time since I needed to know this kind of chemistry.  

Borax used as a flux or firescale preventative when using silver solder is removed with a mild acid pickle. I have gone to a citric acid pickle in the studio to remove the residual borax. The crystals will form in a denatured alcohol solution I use, as the alcohol evaporates and the solution gets stronger. A super saturated borax solution and food coloring can make some impressive crystals to amaze your kids.

r ranson wrote:I wonder if it interacted with some minerals in the water.  Which... scratching the back of my brain here to remember... might make it into a salt?  

I think Borax is the salt of boric acid. Maybe it's some kind of allotrope thing going on.

Hi, thanks for the ideas- I do have some garden vinegar- its 30% instead of the 5% cooking vinegar is.  I will try that, so far no amount of scrubbing/soaking has worked. I wish I had remembered making crystals with the kids years ago, then used a jar I didn't care about. Lesson learned.

Hi, just an update. The 30% vinegar did the job. Took a few days and some scraping but I saved the canning jar. Used straight vinegar and let it sit. Thanks