Question: What does a crimping tool look like/where do we find one, etc.? The cover on the top of the exterior smoke stack to keep the rain out does not fit down on it and it will blow off because it is very loose. What should we do? Is there a gasket or something that you could suggest? Thanks for your help. Answer: Plumbing and heating supply houses sell hand crimping tools. These are needed for installing any stove. You could use some hi-temp silicone caulk to try to attach the cap. Also, you could use a small strip of sheet metal which could be attached to the cap and then screwed or riveted to the outside of the insulated chimney pipe.