No.
You would need to exit Thailand and reenter with the tourist visa.
Is this an eVisa?
Suggest best to enter Thailand with the tourist visa and then obtain visa entry with a border bounce.
You stated that ...,
"THis used to be common practice but I don't know if it is done anymore.."
When was it common practice.
Is your tourist visa in passport or eVisa email?
How long do you wish to visit Thailand?