Probably something simple...

[Jamie Copeland]

Hi all

I store some thinned down sanding sealer in an old jam jar for ease and haven't had any problem with it.

Today I went to use it and the lid was on so tight I ended up piercing it and decanting the contents into a new jar. I tried running the jar under some hot water before I resorted to piercing the lid, but it was pointless.

Any idea why this happened and what, if anything, I can do to prevent this happening again in the future?

 

[Fatboy]

sounds simple I know but did you by chance get any of the sealer on the thread of the jam jar when you last used it?

 

[Steve Maskery]

That was probably it. You could make sure that the lid nd rim of the jar were scrupulously clean before storage,
I've just put away half a tin of paint I don't expect to use for a few years (for which read never). I've pressed a piece of cling film over the surface before putting on the lid. I hope it helps.

 

[Knot Competent]

Have you stored it upright, Steve, or upside down? I was told if stored upside down, any skin would form on the top, so when you inverted it and took the top off, all you got was paint with no skin.

 

[Steve Maskery]

Ooh yes, I'd forgotten that trick. My granddad told me that. Crikey, the things you forget.

But I think both will have the same effect, the idea is to stop air from oxidizing the surface.

With any old paint, even if the liquid is still usable, the risk comes from all the dried detritus from around the rim and inside walls of the tin above the paint itself falling in when you stir the stuff.

 

[Mike.S]

I think Fatboy has the answer. Perhaps invert the jar and trickle some solvent (meths or cellulose thinners?) round the cap thread if it happens again.

 

[Adam9453]

With paint you can just shake the tin once the lid is on to seal any gaps that could leak air. Same effect as storing upside down without the risk of a paint flood if it really leaks

 

[themackay]

I have had exactly the same problem myself Jamie Don't think it takes much to stick it solid I think a plastic tub with a push on lid is the way to go.

 

[rafezetter]

I had this happen to me only today on a container of french polish, so I resorted to a trick I use - a speed clamp the type with rubber heads. I clamp it down and twist using the extra leverage. If that doesn't work I go around the lid: clamp then release, clamp then release to try and "break" the connection. Then clamp up again and twist, it usually works even with really old jars that I've mixed oil paint in.

So far I've never had it happen but obviosuly don't clamp so har you migh break the glass under the lid.

 

[monkeybiter]

I use glass jars from work with hard and brittle plastic lids. They often stick tight due to SS on the threads. As suggested by rafezetter working your way around the circumference, diametrically squeezing can sometimes loosen it. I use waterpump pliers or even my bench vice [very carefully]. It doesn't always work, but as I nick them I just nick extra lids and break them off if they won't yield.

 

[Eric The Viking]

Happens to the jar I store the cotton wad in (for French Polishing).

As stated above: invert, dribble meths down the side, wait 3mins then remove lid with a sharp twist.

That stuff is a pretty good glue, too! I've put some knotting on some very manky floorboards recently, and the loose knots are now really solid, never mind no ooze either.

 

[AES]

+1 for all the above, especially about storing the jars & tins upside down (I do the same with aerosols too).

One extra tip that I find often helps, a piece of thin-ish polythene or off cut from a plastic bag, pulled tight over the opening, then screw the cap or lid on tightly AFTER wiping the threads off with a clean rag or paper towel. And I do the same with wood glue too.

HTH

AES

 

[GLFaria]

Have you stored it upright, Steve, or upside down? I was told if stored upside down, any skin would form on the top, so when you inverted it and took the top off, all you got was paint with no skin.

That's how I usually store my partly-used cans, and it works quite well. Only downside is that when you open the can, the interior of the lid will be covered in fresh paint, so you must take care where you place it.

A word of care - even if you feel that the lid is fully re-sealed, place a piece of cardboard under the can for the some first few days after storing it. Otherwise you may just be in for a not so funny surprise (don't ask me how I found out... it was a half-full five litre can of a very high quality dark greyish-blue paint...)

G.

 

[beganasatree]

2 pieces plastic bag (gloves from petrol station)in between the container and the lid works for me.

Peter