I managed to get the last (3rd) coat of stain on yesterday and looking at it this morning I am very pleased to say there are no bubbles at all. I took as much of the old stain off as possible with paint remover and rubbed down with 80 as you suggested. I lightly sanded before the last coat and it seemed reluctant to accept the stain so I just kept on until it did. It looked a little bit like, greasy, but it has covered.
I am so relieved to have got it done properly at last, it looks so much better than the bubble effect and thank you for all your help. I am so pleased to have got it done before the winter onslaught. Thank you again.
If you click on the little button on the right hand side that says thanks where you see one of TheDec's posts then others will see that he has been previously thanked. The thanks have no value other than to show others posting questions that the person answering more likely to be the type of person that is worthy of listening to.
In my humble opinion TheDec is probably the most helpful/knowledgeable member of this section of DIYnot.
Well done, getting the stain off is a pig of a job.