SeamusG

Sidebar step: Cowl preparation.

This assembly was completed before post 12 but I decided to include it anyhow – a flashback post.

The cowl is now assembled so that necessary adjustments can be made to the firewall area. The cowl is a SIG Sun Dancer cowl. The kit included the 2 halves and 2 lengths of ABS strips about 1/64 x ½. No instructions.

As there were no instructions I noticed that the cowl material is the same as that of the wheel pants, so I used the wheel pant assembly as a guide. I taped the halves together with good old Scotch tape a while back. Bad move – this stuff is a bear to remove. I tacked several points using thin CA. Of course, it bled through the seam onto the back of the tape and my fingers. I applied thick CA to the seam and added several “tack strips” of the ABS strips. The ABS material is too smooth for a good bite. I then sanded the cowl’s seam and one side of the ABS tape. Thick CA worked out fine.

To reinforce the seam I pulled out some 2” fiberglass tape and cut pieces to length. I applied 3M 77 spray adhesive to one side of the tape and applied the pieces to the seam. 3M 77 allows the tape to be positioned easily and it stays put in the very convoluted surfaces inside the cowl. I then mixed up some 30 minute epoxy and put a light butter coat on the tape. A heat gun was used to flow the epoxy being very careful not to overheat the ABS material.

After drying, the entire surface of the cowl was sanded to provide bit for primer, surface filler, and then paint.

The nose of the cowl was then opened up to accept the engine crank / prop backing plate with a drum sanding attachment on the Dremel.

The cowl / engine mount / firewall fitment was tested. Oops. The thrust line of the firewall / mount / engine did NOT align with the cowl’s front opening. If the thrust line is aligned with the cowl’s opening the cowl will not align with the firewall or fuse.

Guess I will share this with SIG’s engineer that gave me the “thumbs up” on using the Sun Dancer cowl with a Hog Bipe.

TTFN