Loosen the lid on Testors enamel square bottles.

[R. Thorne]

Usually open ‘em with my large pliars after running hot water on the lids, but had one that wouldn’t give up the ghost today.  YouTube to the rescue.  Tapped on the top of the lid with the plastic handle 3 or 4 times, then turned it 180 degrees and tapped it again.  Viola!  High tech stuff.

[peteski]

Nice!  There are multiple ways of dealing with stuck lids.  Another way is to stand the bottle upside down then using an eye dropper apply some lacquer thinner or acetone between the lid's lip and the glass bottle.  That will penetrate into the dried up paint in the threads.

I never have this problem because I'm really fastidious in keeping the threads and seal in the lid impeccably clean before closing the bottle.

Edited September 21, 2023 by peteski

[Richard Bartrop]

Applying some gentle pressure under the lid with a knife or screwdriver will sometimes break the seal, though the thinner idea sounds promising.

[Straightliner59]

I use the upside down/lacquer thinner approach. It works excellently!

[Mike C]

I heat mine up with a hair dryer. Sometimes I still need to use one of those bottle gripper pads too. I try not to use a plyers on the lid because I don't want to deform it.

[Mike 1017]

6 hours ago, Straightliner59 said:

I use the upside down/lacquer thinner approach. It works excellently!

?

[Hi-Po]

I use the upside down/ lacquer thinner approach on any size of Testors or Model Masters paint.  Works like a charm.

[Mike 1017]

17 hours ago, Hi-Po said:

I use the upside down/ lacquer thinner approach on any size of Testors or Model Masters paint.  Works like a charm.

If the cap is really stubborn, I use this Jar Opener, 5 Inch Diameter Capacity, Kitchen Aid jar lid and bottle opener, opens screw caps, vacuum caps, pry up lids easily (micromark.com) or a pair of channel locks.

[stitchdup]

I stick the cap in next the hinges of a door and use the door to hold it. comes off with a twist then. as long as you have decent doors and frames it shouldn't do any damage and i think most of us have them near our benches

[iamsuperdan]

I have a small but wide rubber band. It bundled up some green onions or something from the grocery store. Put that on the lid and just twist. 

 

And it's pink, so it stands out in my tool box and never goes missing.

 

[Chariots of Fire]

YUP!  Done the tap thing a number of times.  It does work! ? Also cleaning the edge of the bottle after it is open helps to keep the dried paint to a minimum.

[maxwell48098]

To avoid the caps sticking on any bottle paint, I always completely wipe out the inside of the cap as well at the top edges of the bottle that come in contact with the cap seal. I've done this for 55 years and have never had a problem with a cap sticking.

 

A.J.

[Jim B]

Maybe I'm missing something here, but how does lacquer thinner work on enamel paint?

[ranma]

Personally I use a bic type lighter to heat the cap which works quick, and the cap comes off when using a paper towel .. My main issue is that the paint hardens just after a couple of month's now, and becomes like a rock in the bottle! Odd but true thing is this year at the  U.S. 127 garage sale I bought a set of bottle paints with a copyright for 1986, yet the paint is still perfect and useable. Only the thinner was fairly empty. Original price was 3.99 from Harts..

[peteski]

27 minutes ago, Jim B said:

Maybe I'm missing something here, but how does lacquer thinner work on enamel paint?

Lacquer thinner is a "hot" solvent.  JUst like you not supposed to apply hot paints over enamel (becuase it will wrinkle the enamel), the lacquer thinner will soften the hardened enamel in the lid.  We are not going for liquefying the dried paint (which cannot be done anyway) - just to soften it enough to unscrew the lid.

Like I mentioned earlier, I always make sure the threads, the lip of the bottle and the cap and seal are clean before closing the lid, so I don't have this problem.

[Jim B]

Thanks. Guess this would work with Tamiya as well. 

[Bills72sj]

I go old school mechanical. Channel lock pliers. If it is really bad then then I use my plastic jaw Pana-vise to hold the bottle. Too lazy to clean the cap/threads after every use.

[peteski]

5 hours ago, Jim B said:

Thanks. Guess this would work with Tamiya as well. 

Should work with any paints.

[Straightliner59]

10 hours ago, Jim B said:

Maybe I'm missing something here, but how does lacquer thinner work on enamel paint?

It works because it's a stronger solvent? I use it to cut enamel paint for airbrushing. Shortens drying time, greatly!

[Perspect Scale Modelworks]

On 9/22/2023 at 11:25 PM, Bills72sj said:

I go old school mechanical. Channel lock pliers. If it is really bad then then I use my plastic jaw Pana-vise to hold the bottle. Too lazy to clean the cap/threads after every use.

You have to be careful with this technique. I once cracked a bottle using pliers and a vise. It was like the cap was welded on.

[espo]

Another idea if you don't have any thinner handy. Place the bottle upside-down in a container of warm water. This seems to have the same effect as using thinner.  Remember to clean the inside of the cap along with the bottle opening so that the paint doesn't reseal the bottle. 

[carrucha]

I usually put the bottle in a vice and open it with a pair of pliers.  Works every time but it leaves the bottle cap dented and mis-shaped.

[Bills72sj]

I have been leaning towards getting this...

https://www.ebay.com/itm/325372061702

[bobss396]

On 9/22/2023 at 5:55 PM, Jim B said:

Thanks. Guess this would work with Tamiya as well. 

It does. I have had some old ones I had to get drastic with. Now after each use I clean the bottle and cap with lacquer thinner.

[Bullybeef]

 Brute strength and ignorance is the only way!