Stihl MS 391 muffler bolt question

[Fishnuts2]

Looking for advice on keeping the muffler on my ms391. Pretty sure I was the first to remove the muffler and the bolts were very tight. I reinstalled the muffler bolts as tight as I dared and rechecked them hot. Muffler came loose after a few minutes so I bought new bolts with thread lock on them. Yesterday I ran maybe a half tank through it and the muffler is loose again. Is this an issue for you guys too and how do you fix it?
TIA

 

[066 redeye]

Was it blue locker on them?

 

[singinwoodwackr]

Looking for advice on keeping the muffler on my ms391. Pretty sure I was the first to remove the muffler and the bolts were very tight. I reinstalled the muffler bolts as tight as I dared and rechecked them hot. Muffler came loose after a few minutes so I bought new bolts with thread lock on them. Yesterday I ran maybe a half tank through it and the muffler is loose again. Is this an issue for you guys too and how do you fix it?
TIA

Which Loctite?

 

[Fishnuts2]

Was it blue locker on them?

It was more like a grayish paste.