[KayS]

good evening fellow builders,

while fitting the top cowling to firewall/fwd top skin i was wondering if/how people seal this joint. thing is when airplane (7-taildragger) sits on the ground during rain, the water will probably enter the engine compartment and will flow down the firewall. i don't like that and since i use skybolt fasteners i got the idea to make a seal (rtv or whatever) at the mating area of the cowling and the mounting strips for the skybolts.

what did you guys here? or did you just not worry about it?

cheers
Kay

 

[KayS]

mmh... ok seems like nobody's does here anything,

 

[DakotaHawk]

My cowl is attached with MilSpec fasteners. I didn't do anything to seal the cowl attach joint.

The way I think of it is like this... When I fly in the rain, I fully expect air/rain to enter into the engine compartment from the front air dam. From there, the majority of the air/rain will follow the designed path down through the cylinders and then out through the bottom of the cowl. But some of the air/rain will make it past my poorly fitting baffles and then to my firewall. Likewise, some of the air/rain that has gone past the cylinders will swirl back up and impinge on the firewall as well.

So I find it more important to make sure that my firewall is watertight to prevent water from entering the cockpit. I'm not concerned about water in the engine compartment. Everything up there is designed to work properly and safely even if it gets a little damp. And a watertight firewall is also an airtight firewall - CO considerations.

PS - no flames about the "poorly fitting baffles". They really fit just fine. I'm just exaggerating to make a point.