Can I use a tourist visa to spend 5 months in Thailand with multiple entries?

If you all are 50 years old or above you can apply for retirement visa.

I'm planning to do this too. Just 4-6 months then go home. I have to leave in a couple weeks. I was planning on doing 5 days somewhere else then coming back in for a few more months then going home.

Last time I did this, the officer wanted to see that I had a ticket home (which I did).

Has anyone had any issues with this?

Don't be certain of getting in on the free entry. I got my 60 days, left for a two week trip outside Thailand and on exiting was told by the IO that I would need a visa if I intended to return.

He said he would put a note on the system, so I did indeed re enter with a visa.

You're talking about the 6 month METV <- multi-entry tourist visa that you get from a thai consulate in your country before you come here. That visa (if used correctly) can give you almost 9 months of stay in thailand (by taking 60 days, then the 30 day extension, then bouncing out and back, getting another 60 days, taking another 30 day extension, then bouncing just before the visa expires to get a final 60 days and extending that by 30 too)

Just so you're clear about what you're referring to; there is no "tourist visa on arrival" and

You're talking about is just showing up here and getting stamped in FREE entry for 60 days on what's called a visa exempt entry. You can extend that 60 day stamp once for 30 days for 1900baht at the immigration office. Then as you mentioned you'd exit/re-enter thailand to get a new 60 day free entry stamp (which you could extend for 30 days as well)

Entering visa exempt on the free 60 day entry taking the 30 day extension then exiting/re-entering to get a new 60 day entry w/extension would certainly give you the time you want without buying that METV before you come here.

You aren't gonna LIVE here on free entry stamps, but you should get 6 months out of it relatively trouble free per year like you mentioned