installing stove and chimney pipe. do I need sealant?

I'm finally getting around to installing my Morso 1410 Squirrel and Duravent Class A chimney. I was all set to go back in April, but hurt my back. It seemed prudent to heal completely before doing any climbing, lifting, and twisting.

It's been awhile since your advice in April. A refresher:
The install is in my sunporch, glass windows all around from about 34" up. I'm going through the wall so I don't have to cut an enormous hole in my painstakingly-restored 91-yr-old T&G beadboard ceiling. Yes, most of you guys told me to go through the ceiling and heavily-insulated attic. I know the wall install will make it draft more poorly. Still, when California bans wood-burning altogether, I can repair the hole in the wall much more easily than a hole in the ceiling.

To date:
I did manage to get the wall thimble installed, despite my back injury.

Today's question:
When I connect the sections of double-walled stove pipe to the stove, and then to the Class A Duravent at the thimble, do I need a high-heat mastic or sealant? The stove pipe will be screwed together, but what keeps it from leaking smoke and gases into the room? Also, the instructions on the Duravent say to just twist and lock the pieces together, with screws optional. What are your thoughts on this? And, again, should I be using mastic or sealant?

Thanks to anyone who is answering today. I know you'd rather be outside!

Thanks! I'll see if I have any. I vaguely recall buying some back in the spring. If not, the local stove shop will be glad for some business today.

I found a tube of it. I must have had this conversation with myself a few months ago, but forgot the answer.

So, now that I've been playing with stove cement, and really trying to put this thing together, it seems I have a choice to make.

(1) I can either simply use stove cement to connect the cast iron flue collar to the Duravent double-wall stovetop adapter, or
(2) I can use sheet metal screws through the 2 little holes, puncturing the crimped portion of the stovetop adapter.

The instructions for the stove say to use a minimum of 3 screws (even though there are only 2 holes in the cast iron collar.) But, the instructions for the Duravent chimney pieces say to not pierce the inner liner. Does this apply to both the chimney pipe AND the stove pipe? I'm concerned that the stove cement won't have enough holding strength if something bumps it.

What would you do?

So, should I skip the screws? I'm sure the answer is obvious to anyone who has done this before. I don't want to put holes in the pipe, and then find out it was a bad idea. (You can laugh at my newbie-ness!)

Does cast iron drill out easily? I'll probably just put the two screws. At this rate, I'll get this thing installed by July 2012.

Thanks! Maybe I'll get the stove attached to the thimble by dark.

Didn't quite get it attached to the wall last night, but it's gonna happen this morning! Some parts did meet up!

Question: Do you guys recommend putting any anti-corrosion compound on the screws and bolts as I install it? If I don't, will it be a bugger to take apart later for maintenance/ repair?