Removing a bottle cap without damaging it is easy. Simply pry around the edges of the cap with a flat head screw driver. Try to pry evenly the whole way around. The cap should come off easily. Be careful not to overly deform any one part of the cap. If you use a standard bottle cap opener the cap can never be reused due to it no longer being able properly seal the bottle. Check to make sure the rubber seal on the inside of the cap is still pliable. If it is hard or spun freely before removal this cap needs to be replaced. This is very common with glitter lamps as the chemicals inside of them degrade the rubber in the cap.
Glitter lamps have a plastic plug underneath the bottle cap. This can be removed by pulling on the sides until the vacuum is released. It is almost impossible to remove these without destroying them. Fortunately these are easily available online. To find the replacement for these search online for "Caplugs 99191209 Plastic Cap for Threaded Connectors. RC-11, PE-LD".
Bench cappers are a necessity. Using hose lamps and other methods simply does not work. You may think you got a good seal, but over the years they do not hold up. Save yourself the heartache and buy a bench capper.
Still trying to be cheap? This is a hand capper and will not work either. It requires a lip on the bottle to grab on to and Lava Lite lava lamps do not have this lip as well as most Chinese lava lamp.
Screw caps are the easiest to remove, simple unscrew them by hand. Some of these caps can be on very tightly and it can help to wrap rubber bands around the cap for a better grip. Sometimes these caps will crack due to their age when taken off. When putting the cap back on, pay careful attention to the rubber o-ring. It must be properly seated in the lid for a good seal. The cap should be snug, but if tightened very tight the cap will break.
To remove crimp caps you need a small screw driver to pry around the bottom lip. To put the cap back on, use the screw driver to press the cap back into its original shape. A pair of plyers can be used to give a tight seal on the cap, but this cannot be done several times or the cap will eventually get damaged. If possible it is best to replace the cap with a bottle cap if the lamp is the correct size for one.
Notice the wide neck? These are the only types of globes that a hand capper will work on.
Larger lamps such as the Lava Lite Grande also use crimp caps. If you intend to open one of these it is best to replace the cap. To do this you can purchase these plugs and glue it to the globe with silicone. Note you will also need heat shrink to make sure the plug stays on the lamp since the silicone is to create an airtight seal and not to actually ensure the plug stays in.
Part # ... XW2.12/2.29YW1
(A) Small O.D. ... 2.120”
(B) Large O.D. ... 2.290”
(C) Small I.D. ... 2.036”
(D) Large I.D. ... 2.210”
(E) Length ... 1.000”
(F) Flange OD ... 3.790”
Box/Mini/Micro QTY ... 300/60/6
These caps are the easiest to work with. Simple unscrew them like any other bottle. Be careful when screwing the cap back on. If you apply too much force the cap can crack. These caps are often brittle with age, especially if they were exposed to the sun.
3D Printed Replacement
To support Duane please purchase his 3d model from his Shapeways store here.
You will also need an o-ring for the printed cap. The dimensions for it is 1-1/2"x1-3/4"x1/8" #81 02-1618P .
When printing these caps remember lava lamps reach temperatures up to 120F so made sure to use a plastic rated for well above that. Also print with the highest quality and resolution possible. The plastic o-ring needs to make an air tight seal against the plastic cap. If there are small grooves in the printing the o-ring will not form a seal. It is possible to add a small amount of silicone caulk between the o-ring and the cap, but it is best to try to avoid the need for that.
Some sanding, filling, and painting will be needed to bring the exterior finish of the cap to an comparable finish to an original cap. Testors craft metallic gold is a very close finish to the original cap color if you use a flat clear coat after using the gold paint.