Dose - Advice on redosing with GBL

[Synesthesiac]

Swim has some GBL and is currently enjoying it very much. He is planning to convert it to GHB as soon as possible, but meanwhile he was wondering what a safe amount of redosing would be with the GBL. Swim finds that 1.5ml is a good starting dose for him, and that he feels like a 1ml redose about an hour later is good for him. So far swim has only redosed twice a night, doing a total of 3.5 ml over two hours. Swim has a very high metabolism, and the full effects are usually felt within 10-15 minutes of ingestion which is faster than most other people I have noticed.

How long is it advisable to continue redosing? Is there an upper limit to a single nights use that people would recommend?

Thanks in advance.