So I now have an oooooold crestworth jet.

[alan lovedog]

just bought another jet lava lamp on ebay.

turned up today and what a surprise - it's actually a pre mathmos crestworth one.

differences being, the cap and base are metal rather than plastic, it wants a 40w golfball bulb instead of the 30w of the plastic ones and the bottle has a different type of top on.

anyone have any experience of these? - will the bottle play nicely with a newer mathmos base, and will a more modern bottle work with the old base?

[Astralav]

yes you can change Jet bottles with Crestworth one (just need the correct cap).

By judging the condition of your bottle, I would say it is a modern Mathmos one.

[alan lovedog]

seems to be from the changeover period - the box says mathmos in small letters at the back but crestworth in the main.

the cap seems to have the black disc on top integrated - so might be tricky to swap with other bottles.

the bottle seems to be the original.

[Astralav]

It's very easy to swap the bottle as you can screw a plastic T cap from a Crestworth to a modern Jet bottle.

It's possible yours is original if the owner kept it in a box and never used it, but it's unlikely.

Anyway I'd rather have a late cristal clear bottle than an old original cloudy and shot bottle.

And after all, Crestworth and Mathmos are the same company, so who care? :-)

[Simon Lloyd]

CONGRATS ALAN,

Nice lamp - I prefer the older metal top & base - what does it say on the base plate?

BTW The bottle looks fine - the formula of the wax is MUCH better than later more modern ones - it snakes and blobs nicely, melts at a lower temp.

You may be able to "free" the lid from the metal cap - you may be able to melt the adhesive and separate them - but be careful that the plastic lid does not brake. This can be done with a hairdryer, or boiling water but be careful!

[Astralav]

Every time I see a Crestworth Lava lamp in the flesh, the bottle is always at least a little cloudy or the wax is shot, that's why I thought your was a new one as it looks so nice, but if Simon says it's genuine, I guess he's right as he's got far more knowledge than me about Crestworth.

Simon : I noticed on my lamps, the purity of the glass is far better on later Jet bottles than on early Crestworth ( a lot more defects in the glass) do you confirm this?

[Simon Lloyd]

Hi Astralav,

The older bottles tended to be made from slightly thicker glass - so perhaps that & the fact that they are older leads to more defects?

[alan lovedog]

just checked the base - it actually says mathmos on the bottom so I guess it must be from some time before they dropped the crestworth name.