Any body know any techniques on how to scratch build a cowl? Never did it before but need a cowling for a plane that was givin to me and didn't come with one.


                 TIA
                               -Steve

Hi Lee ,

It's a impact with a stiletto/jet style fuse, amazingly i have no pics of it in my computer 

Here's a technique.

Install the engine in the airplane.

Build up a cowl around it using small pieces of scrap balsa and Hot Stuff. 

When engine is totally (and crudely) boxed in, remove the engine and "pretty-up" the cowl with sanding blocks. 

Once the outside looks good and blends into the model, fibreglas or silk it and get the outside lookin' good.

Take it off the model and demel out as much wood as you dare.

Any body know any techniques on how to scratch build a cowl? Never did it before but need a cowling for a plane that was givin to me and didn't come with one.


                 TIA
                               -Steve

Hi Steve,

I use the same side wood as the finished sides of the fuselage to make the sides of the cowl.  I like to use small ply tabs with 2/56 blind nuts in them for attachments.  These will fit up into the fuse sides.  I use a piece of wood thick enough for the bottom to get the bottom shape I want.  Then a large thickness to use for the front of the cowl.  Tack glue the cowl sides to the fuse, then put the bottom on it so that it is the right width.  Fit, and insert the scrap block in the front of the cowl.  Shape this as close as you need for the outside shape.  Now, pop it off and hollow the inside to fit around the engine, etc., (you can mount the engine to check your fits) and add any cooling vents , and other openings.  I use an X-Acto "gouge" (looks like a circle about 1/2 diameter) to do most of the hollowing inside.  Apply .5 oz. fiberglass or CF veil to the outside and apply your finish.  Forgot, you will need to mark and drill small holes for the 2/56 socket head bolts to go through for the mounting bolts in the fuselage sides. 

If it's a "short" cowl like an Ares, etc., you will probably use one 4/40 at the bottom/back of the cowl for attachment, and 1/8th" dowels that set into receiving blocks at the front.