How to secure loose head on old style street lamp Post your questions and get answers concerning many areas of this subject

[Emmaxv]

Hi
I'm posting on behalf of my Dad.
He has an old fashioned type gas street lamp in his garden.
The problem is that the head of the lamp is coming loose from the post so it's started rocking a little.
Is there anything he can apply or do to secure it?
He wondered if there was some kind of tape type stuff?

Thanks.