Page 1 of 2 12 LastLast
Results 1 to 15 of 27

Thread: Has anyone else had this happen?

  1. #1
    Join Date
    Feb 2003
    Location
    McKean, PA
    Posts
    15,595
    Blog Entries
    1

    Has anyone else had this happen?

    A while back, maybe a couple of years, I purchased a can of Orange Shellac for a project I was doing. I didn't end up needing the whole can so I put it on the shelf with my other finishes. This week I was looking for a can of stain that I had and moved the can of shellac as I was looking for the can of stain.

    Today, I went to get my can of pvc cement for a different project and as I walked over to the shelf I saw a puddle of brown stuff on the shelf and also on the floor. As I moved stuff off the shelf wiping off the wet shellac, I found the can of shellac looking like this:
    IMG_0028.jpg

    That large lump on the side is dried shellac. Apparently the shellac and alcohol have eaten through the side of the can. It appears the leaking has been going on for some time. The first leak appears to have started at the side seam, but there is also a pin hole on the other side, covered by the label.

    My shop is heated/cooled by the house system so the can did not rust through from the outside. This is the second time I have had this happen with a can of shellac.

    Is this a common occurrence with old shellac?
    Lee Schierer
    USNA '71
    Go Navy!

    My advice, comments and suggestions are free, but it costs money to run the site. If you found something of value here please give a little something back by becoming a contributor! Please Contribute

  2. #2
    Join Date
    May 2012
    Location
    Glenmoore Pa.
    Posts
    767
    Looks like it happened right at the seam on the can.

  3. #3
    Join Date
    Nov 2006
    Location
    NE Ohio
    Posts
    6,983
    Is this a common occurrence with old shellac?
    Sort of - the shellac attacks the solder in the seam.
    You actually got extremely lucky. I wasn't that fortunate.

    One can I had in the basement just leaked at the seam like yours.
    Another I had in a downstairs bedroom blew up!

    When the shellac attacks the solder it often forms a lot of gas in the can. If there's no way for the gas to escape, it will build up until the lid blows off.
    I've seen cans so rounded on top and bottom they look more like a bottle than a can.
    My granddad always said, :As one door closes, another opens".
    Wonderful man, terrible cabinet maker...

  4. #4
    Google up leaking shellac cans..... your not the only one!

  5. #5
    Join Date
    Jul 2010
    Location
    Northern Kentucky
    Posts
    3,279
    Quote Originally Posted by Rich Engelhardt View Post
    Sort of - the shellac attacks the solder in the seam.
    You actually got extremely lucky. I wasn't that fortunate.

    One can I had in the basement just leaked at the seam like yours.
    Another I had in a downstairs bedroom blew up!

    When the shellac attacks the solder it often forms a lot of gas in the can. If there's no way for the gas to escape, it will build up until the lid blows off.
    I've seen cans so rounded on top and bottom they look more like a bottle than a can.
    I use about of a half of the can of shellac , some time later open the can and it POP [explode ]

  6. #6
    Join Date
    Feb 2003
    Location
    McKean, PA
    Posts
    15,595
    Blog Entries
    1
    Quote Originally Posted by Rich Engelhardt View Post
    Sort of - the shellac attacks the solder in the seam.
    You actually got extremely lucky. I wasn't that fortunate.
    The funny thing is this can was one of those paint cans lined with a plastic liner. Apparently old shellac is pretty potent.
    Lee Schierer
    USNA '71
    Go Navy!

    My advice, comments and suggestions are free, but it costs money to run the site. If you found something of value here please give a little something back by becoming a contributor! Please Contribute

  7. #7
    Join Date
    Dec 2010
    Location
    WNY
    Posts
    9,648
    I've had this happen at least 3 times. The last time it was on a can less than 1 year old. I reported it on another forum and found that lots of folks had had the same problem. Another guy who'd had a can leak reported it to Zinsser and they wrote back to him like it was the first time they had ever heard of the problem. This problem seems like it could result in a someone's house, business, etc. burning up and I would think Zinsser would be all over a solution - years ago, but it doesn't seem that way. I guess the only solution is to transfer it to a glass jar.

    John

  8. #8
    Join Date
    Nov 2006
    Location
    NE Ohio
    Posts
    6,983
    The funny thing is this can was one of those paint cans lined with a plastic liner
    It's actually some sort of acrylic coating that's sprayed on the inside of the can - pretty much like the stuff used to line beer cans.
    All it takes though is one tiny pin hole in the film that allows the shellac to contact the solder in the can's seam.


    Stirring the shellac too vigorously can also damage the film.

    Another guy who'd had a can leak reported it to Zinsser and they wrote back to him like it was the first time they had ever heard of the problem. This problem seems like it could result in a someone's house, business, etc. burning up and I would think Zinsser would be all over a solution - years ago, but it doesn't seem that way
    That's odd since I first heard about the problems of shellac and unlined metal cans from the Zinsser sales rep back in the 1970's.
    We were discussing why Zinsser used metal cans & Parks Corporation used plastic containers for shellac.
    I recall him saying that metal containers sealed & plastic ones didn't.
    It wasn't hard to prove his point since all the plastic jugs of Parks we had on the shelf were oozing shellac from around the lid.
    My granddad always said, :As one door closes, another opens".
    Wonderful man, terrible cabinet maker...

  9. #9
    Join Date
    Mar 2003
    Location
    Southport, NC
    Posts
    3,147
    The alcohol used as a thinner in shellac is hygroscopic meaning it will absorb water from its environment. If a can has been opened, it will have absorbed some moisture and that moisture will cause rusting of metal cans. That's the reason for the lining inside cans of shellac. The seam is the areas most prone to attack by water.

    In it's basic form, shellac is nothing more than shellac resin dissolved in alcohol. There are no other chemical components. So, the culprit is moisture or water. Once the can has been opened, the shellac should be used within six months to a year. The more it's opened and the longer it's opened the faster it will degrade.
    Howie.........

  10. #10
    Join Date
    Dec 2010
    Location
    WNY
    Posts
    9,648
    Quote Originally Posted by Rich Engelhardt View Post
    That's odd since I first heard about the problems of shellac and unlined metal cans from the Zinsser sales rep back in the 1970's.
    I'm really surprised Zinsser hasn't worked harder to solve this problem. All it will take is one can of shellac to ooze into someone's furnace, hot water heater, boiler, etc. and burn down the house or business and they will by ripe for a huge lawsuit. They don't even put a warning label on the can. Their lawyers are either very confident or very stupid.

    John

  11. #11
    Join Date
    Jul 2010
    Location
    Northern Kentucky
    Posts
    3,279
    [QUOTE=Rich Engelhardt;2284554]I

    Stirring the shellac too vigorously can also damage the film.


    the shellac container had a warning about the way that the contents was mix, do you shake or stir the contents, I think that the warning advise against shaking the shellac

  12. #12
    Join Date
    Nov 2006
    Location
    NE Ohio
    Posts
    6,983
    Ray,
    I shake the can.
    Stirring is fine as long as you use something that can't possibly damage the can's liner.


    @ John,
    I don't know why Zinsser doesn't do anything about it. It's not like it's a new thing that just started to happen.
    Zinsser has been using lined cans for as long as I can remember - which goes back to 1967 or so - so they know there's an issue with their products and bare metal.


    If a can has been opened, it will have absorbed some moisture and that moisture will cause rusting of metal cans
    No - the culprit is the shellac, not the alcohol.
    If the alcohol was the culprit, then what you say would also hold true for cans of alcohol - but - I've never seen a can of alcohol rust from the inside out.
    & alcohol cans are unlined.

    Moisture may be acting on the shellac in some way, but, what's happening in the cans is defiantly not moisture causing the cans to rust.
    In the probably dozens of case I've seen, I don't recall ever seeing rust signs on the insides of the cans.
    Last edited by Rich Engelhardt; 07-05-2014 at 9:23 AM.
    My granddad always said, :As one door closes, another opens".
    Wonderful man, terrible cabinet maker...

  13. #13
    Join Date
    Jul 2010
    Location
    Northern Kentucky
    Posts
    3,279
    Quote Originally Posted by Rich Engelhardt View Post
    @ John,
    I don't know why Zinsser doesn't do anything about it. It's not like it's a new thing that just started to happen.
    Zinsser has been using lined cans for as long as I can remember - which goes back to 1967 or so - so they know there's an issue with their products and bare metal.


    No - the culprit is the shellac, not the alcohol.
    If the alcohol was the culprit, then what you say would also hold true for cans of alcohol - but - I've never seen a can of alcohol rust from the inside out.
    & alcohol cans are unlined.

    Moisture may be acting on the shellac in some way, but, what's happening in the cans is defiantly not moisture causing the cans to rust.
    In the probably dozens of case I've seen, I don't recall ever seeing rust signs on the insides of the cans.

    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 ?

  14. #14
    Join Date
    Dec 2010
    Location
    WNY
    Posts
    9,648
    Rich, I agree, it can't be water alone or what gets absorbed by the alcohol. As you said, cans of DNA don't rust through and I open those a lot more than I do cans of shellac. It could be that water causes some form of acid to form in a can of shellac which corrodes the can. I don't know, but it seems to happen with amazing frequency. I'm really surprised there haven't been serious problems from cans leaking and causing fires. I think I'm going to start putting the Sealcoat I buy into 1 qt. Mason jars. That should solve the leaking issue. Of course, if I drop one I'll have a big mess to clean up.

    John

  15. #15
    Join Date
    Jul 2010
    Location
    Northern Kentucky
    Posts
    3,279
    Quote Originally Posted by John TenEyck View Post
    Rich, I agree, it can't be water alone or what gets absorbed by the alcohol. As you said, cans of DNA don't rust through and I open those a lot more than I do cans of shellac. It could be that water causes some form of acid to form in a can of shellac which corrodes the can. I don't know, but it seems to happen with amazing frequency. I'm really surprised there haven't been serious problems from cans leaking and causing fires. I think I'm going to start putting the Sealcoat I buy into 1 qt. Mason jars. That should solve the leaking issue. Of course, if I drop one I'll have a big mess to clean up.

    John
    can we buy strong acid in plastic bottles or jugs ?
    if you store Sealcoat in the Mason jars THEN buy kitten litter in big bags and keep one bag open and close to the possible mess site

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •