Has anyone else had this happen?

[Rich Engelhardt]

if the shellac will cause the storage cans to rust then will shellac cause your tools or other steel items to rust if they touch shellac ?

Nope - the shellac dries too fast for one thing and it also forms a nonpermeable film that won't allow rust to form.

It could be that water causes some form of acid to form in a can of shellac which corrodes the can.

John - possibly - but - I've seen cans that were unopened build up pressure and the lids and bottoms get domed shape.
They'd be sitting on the shelf right next to cans that were from the same mfg. lot that were fine.

It's puzzling at best.

It doesn't seem to matter either if the shellac is orange, blonde, dewaxed, ,,,,what pound cut it is or what age it is - although older cans that have been opened do seem a bit more susceptible - but - I've seen fairly fresh cans blow their lids also.

My solution to the problem is to stick the cans I use in a plastic bucket & drape a towel over the top.

[Mike Monroe]

Coincidental timing of this thread for me. This past weekend I cleaned up a small mess left from an old, old can of shellac that had leaked it's contents. Luckily there was little left in the can so it wasn't too bad of a mess. The seal around on the bottom of the can failed, no rust, just a small leak the allowed the contents to run out onto the shelf and drip down on to a gallon can of DNA below.

[John TenEyck]

Nope - the shellac dries too fast for one thing and it also forms a nonpermeable film that won't allow rust to form.


John - possibly - but - I've seen cans that were unopened build up pressure and the lids and bottoms get domed shape.
They'd be sitting on the shelf right next to cans that were from the same mfg. lot that were fine.

It's puzzling at best.

It doesn't seem to matter either if the shellac is orange, blonde, dewaxed, ,,,,what pound cut it is or what age it is - although older cans that have been opened do seem a bit more susceptible - but - I've seen fairly fresh cans blow their lids also.

My solution to the problem is to stick the cans I use in a plastic bucket & drape a towel over the top.

The ethanol and iso-propanol used by Zinsser may not be 100% free of water by the time they get it into the can, or perhaps not all the time.

John

[Robert LaPlaca]

Interesting, I have had this happen on at least three different cans of Zinsser shellac, but the failed solder joint was at the bottom of the can not side seam..

[glenn bradley]

I have had two cans of Seal Coat do that over the last couple years; never in the ten or so before that. Each time Zinsser sent me a check for the MSRP amount of a new can in my area. I thought I was just amazingly lucky like I am at the Lottery . Apparently Rustoleum needs to consider kicking their QA requirements back up where they used to be.

[Rich Engelhardt]

Apparently Rustoleum needs to consider kicking their QA requirements back up where they used to be.

I guess it's possible that RPM is caught in the middle also. I hate to admit it, since I really don't like RPM Industries....& I mean, I REALLY don't like RPM...but - Zinsser did put some sort of secret additive in shellac to extend it's shelf life..I guess it's possible that VOC regulations caused some sort of reformulation.
OR - the real culprit may be the can liner.
Maybe the can liner is different?
Thinner coat as a cost savings measure?
Reformulated & now is more susceptible to alcohol?

Each time Zinsser sent me a check for the MSRP amount of a new can in my area.

That's probably the best information to have!!
Next time a can leaks or blows up, I'll make sure I contact Zinsser.

[Charles Neil]

Shellac can be slightly acidic, it can eat thru an unlined metal can, or if the lining gets scratched, the best way to store shellac is in glass containers, it doesnt happen often and takes a good while , but it can eat thru..

[Phil Mueller]

This is an old thread, but this just happened to me. Fortunately, I had read this thread and put most of the shellac into a glass jar. The remaining small amount left in the can is now a sticky mess on my shelf. I only brought this thread back to remind folks of this issue.

[Tom Bender]

Thanks Phil, I was unaware.

[Charlie Hinton]

I have had a wide variety of cans fail and leak.

[glenn bradley]

Good reminder. A lot of modern cans are lined but, just not well enough. I always decant into glass if I am going to store the liquid for any period of time. Mason jars are cheap and come in many sizes/mouth openings.

[John TenEyck]

Be aware that this can happen to cans containing waterborne finishes, too. I had a 2/3's used can of Kem Aqua Plus spring a leak when I picked it up a month or so ago. It was about 15 months old IIRC. After I got the leak contained I opened the can to see what it was like inside. Rust everywhere.

Target Coatings packages their products in plastic pails. How smart of them.

John