7.5 MONTH OLD LAB MIX MALE

Question
I ADOPTED MY DOG 5 MONTHS AGO.  I WORK ALL DAY - HE IS GATED IN THE KITCHEN WITH KONGS OF VARIOUS SHAPES AND SIZES.  WHEN I GET HOME FROM WORK 7-5:30 I TAKE HIM FOR A SHORT WALK AND THEN FEED HIM.  I TOSS BALL WITH HIM FOR ABOUT AN HOUR AFTER THAT.  WE GO FOR 4 SHORT WALKS PER DAY AND 4 DAYS PER WEEK WE DO 3 SHORT WALKS AND 1 40 MINUTE WALK.  THE CLIMATE DOES NOT ALLOW FOR US TO BE OUT LONGER THAN THAT AT THIS TIME OF YEAR...HE IS A BITER.  I DO NOT KNOW IF I MADE HIM THIS WAY OR NOT.  - HE IS NOT AN AGGRESSIVE BITER MORE SO HE USES HIS MOUTH LIKE A HAND TO STOP YOU FROM MAKING HIM SIT OR TAKING HIM BY THE COLLAR -OR TO PUSH YOU AWAY.  HE ALSO BITES YOUR CLOTHES TO INITIATE PLAY.  I HAVE TRIED TO IGNORE HIM BUT HE THINKS ITS A GAME.  I HAVE TOLD HIM NO BUT HE THINKS IT S A GAME.  I NOW CRATE HIM EVERY TIME HE PUTS HIS MOUTH ON ME OR DOES SOMETHING HE SHOULDN'T.  I LOSE MY PATIENCE WITH HIM - AS HE JUST KEEPS REPEATING THE BAD BEHAVIORS.  I DO REWARD FOR GOOD BEHAVIORS.  I TOOK HIM FOR 8 WEEKS OF PUPPY CLASS THAT FINISHED IN DEC IN TWO WEEKS WE ARE GOING TO START THE SECOND TIER...DO YOU THINK THIS WILL HELP?  THEY TOLD ME AT PLAY GROUP 1 HR PER WEEK I HAVE TO PUT HIM IN TIME OUT AND BE CONSISTENT BUT I AM NOT ALWAYS IN THE HOUSE FOR THE TIME OUT CRATE.  I REALLY AM STARTING TO NOT ENJOY MY DOG MORE THAN I DO ENJOY HIM..RIGHT NOW HE IS IN TIME OUT FOR THE 10TH TIME IN THE PAST 2 HOURS.  DO YOU THINK ITS NOT IMPACTING HIM ANYMORE?  I HAVE READ SO MANY TRAINING MANUALS IM GOING NUTS.  I THOUGHT MAYBE I WOULD HAVE A BEHAVIORIST CK HIM OUT BUT IT MAY BE ME THAT NEEDS THE TRAINING.  I DO LOVE MY DOG I JUST DONE LIKE HIM AT TIMES.  HE DOESNT SHUT DOWN EVER!  HOW MUCH PLAY TIME IS ENOUGH AND WHY DO I FEEL GUILTY IF I DONT WANT TO PLAY FOR 4 HOURS EACH NIGHT?
ANY THOUGHTS ON THIS IS GREATLY APPRECIATED...

Answer
Well what you can do when he does that,is use a water bottle and spray him and say 'out' loud and firm-this is rough play and he isn't trying to hurt you,but it is annoying and you want it to stop,so spay him and you can still put him in his crate for about five minutes after that

And yes it is good that you are going for more obedience classes that will help him a lot