I've found the articles/instructions on how to make a plastic cowl from a soda bottle and a foam plug, but I've only seen one picture of a cowl that has been made that way. Does anybody out there have any examples of cowls they've made from plastic soda bottles? I know it would not be very complicated to make one from fiberglass, but I'm looking for the easiest way because it's just for an Avistar that I'm using for aerial video....the front bushing on the engine is throwing a good bit of fuel/oil, which ends up covering my camera lens. I think I can make a cowl to help contain all of the oil and keep it away from the camera. I was just curious how other folks' projects turned out.

Dave

Hi!
Pepsi bottles for my Henschel 129 WW2 attack bomber

On my Dazzler...

That is exactly what I was looking for! Both of you did great jobs...I hope mine will look half as nice.

Newc, what size soda bottle did you use? Also, did you form a plug out of wood or foam and then use your heat gun to melt it to shape? It looks so good it's almost like you just slid the soda bottle over the fuselage and melted it to match.


Dave

I heat shrunk this cowl over an existing cowl as an experiment.

Bill

Here are a couple of pictures of the plugs that I made. Foam covered with balsa, shaped and then varnished, etc. I don't remember exactly which bottles I used, but seem to recall that I used a one liter pop bottle for the Dazzler and a wide mouth apple juice bottle for a larger cowl - just large enough for the plugs to fit into the cutoff neck end. I used my monokote heat gun to shrink the pop bottle. One thing that I did that you may wish to consider is - don't throw away the bottle caps. Instead, put a tire valve stem in it and then after shrinking the plastic put the top on the bottle and pump air - I have a compressor - in the valve stem and this will expand the plastic away from the plug. See third photo.

The valve stem idea is one I've never seen before. I will be getting one today to try it out. Thanks for the tip, Dzl

About that valve stem idea...............

For that pressure to expand the bottle, the bottle has to be intact, right? And the top is still on an intact bottle when you put the cap with the valve stem on it back on the bottle.

How did you get the plug into the intact bottle?

Good question, darock, but no. I guess that I didn't explain it enough. Certainly the bottle has been cut off to insert the plug with the narrow end of the plug toward the bottle top. The air pressure is developed when air is pumped in due to the tight fit between the shrunken bottle and the plug, and the air pressure quickly expands the bottle area around the plug to break loose the plug from the bottle.

Hope that this helps you understand the process.