SeamusG

I am using a SIG Smith Miniplane 2 piece cowl on a current project. I have no experience with assembling cowls. Can someone give me a quick overview of the official SIG assembly approach? Yes, I have done some research on best practices when assembling ABS cowls, just need to know how SIG thinks it should be done.

TIA,

chutt

My Feedback: (1)

Buy a fiberglass one... is much more strong and easy!!
On my TF Cessna Skylane I bought a fiberglass cowl...

Cheers,

Andre.

outdoorhunting

Ditto, chutt. www.fiberglassspecialties.com Just go fiberglass, stronger, easier to work with & the finished product looks 10 times better Good Luck

CustomPC

That Link should be:

http://www.fiberglassspecialtiesinc.com

somegeek

My Feedback: (2)

I had to build one recently and I used CA glue. Also used pieces of the molding to install on the inside surface of the seams to reinforce them. The CA seemed to almost melt the plastic a little which yielded a very solid bond. Smoothed over edges with microballoons. Had to do some wet sanding to get a good paint finish but the finished result looks nice I think.

somegeek

DaveB

The previous post regarding assembling an ABS cowl using CA is IMO the best way to assemble it. For me, I find that "Squadron Putty" does a good job on filling cracks, dent, etc. in preparation for painting. On the other hand, ABS cowls seem to have a relatively short life, ergo the advice offered to purchase an after market fiber glass cowl is sound. My advice; assemble and finish the ABS cowl as described and use it until it's toast (which probably won't be too long). Meanwhile, also purchase the fiber glass cowl and finish it as a replacement.

DaveB

Campy

My Feedback: (1)

I use some tape to hold the cowl in the correct alignment, then add 4 or 5 SMALL DROPS of THIN CA to the inside of the cowl. After that has dried I take some 1" wide strips of 2 oz fiberglass cloth, lay them over the seams and glue them in position with thin CA. I also CA a strip of fiberglass to the inside of the outer edge as re-enforcement for the screw holes.

A tip for you..... Take the scrap pieces of the ABS cowl and cut them into small pieces (about 1/4" square). Put the pieces in a small jar with a SMALL AMOUNT of acetone and let them disolve into a thick "slurry"/paste. Use the slurry to fill the seam on the outside of the cowl, Your fill will be colored matched to the cowl, and if you work carefully, there will be almost no sanding involved

outdoorhunting

OOPS!!

alpinestar

I built one of these planes years ago & used a 70 surpass in it.. I kept the cowl in two peices & used some plywood strips & screws to hold the two halves together. Made for a more convenient means of removing the cowl to access the engine.
Cheers

*JCB*

My Feedback: (9)

For Sig's plastic parts i have always used modeling plastic cement. This will hold pretty well and then i will reinforce the joint on the inside with some CA. I have used the plastic cement as filler before, but i discovered that epoxy with a bunch of micro balloons (or baby powder in my case) does a dang good job.

Then if you do some good prep work before painting, you will never see the joint and it will look as good as any fiberglass cowl.

SeamusG

Thanks to all for prompt responses.

Bob Nelson of SIG Mfg responded:

Knowledge is truly a dangerous thing [:-]

r2champion

Just a thought about ABS vs. Fiberglass cowls, what would be wrong with putting your ABS cowl together and putting a layer of fiberglass covering the entire inside? Wouldn't this give the strength and rigidity of a fiberglass cowl, or atleast stronger than just ABS? There would be an increase in overall weight, but from my experience, and ABS cowl is lighter than a fiberglass cowl to begin with right? I have only dealt with a couple of cowls in my builds so far, one fiberglass and one ABS. Therefore I'm lacking the knowledge rule this out as an option. Any thoughts are appreciated!

Deadeye

ABS with fiberglass inside will weigh more than fiberglass, but is a good alternative if $$ is tight.