judsterky

My Feedback: (4)

Are you all sick and tired of seeing your wood screws in your cowl vibrate loose every year. Then you have to CA the screw holes back numerous times. Well I have the answer for that.
I purchase 4-6 threaded inserts from your local specialty hardware store for about 20¢ a piece and I also buy 4-6 nylon screws I prefer the 6x32 size and then buy 4-6 black rubber washers that will withstand vibration. I simply drill a whole through the cowl and into the fuse with a drill bit the same size as the nylon screws. Then I remove the cowl and enlarge the fuse wholes so you can screw your threaded inserts in. ( be sure to used a dab of 6 min epoxy on the threaded insert threads, be careful not to get epoxy on the inner threads. Install all the inserts and let dry for 15 minutes and install your cowl using your nylon screws and rubber washers. For better looks I painted my nylon screws heads with testers red paint to match my cowl. I believe you will be impressed how well this with hold up for you over time.

Campy

My Feedback: (1)

What also works very well is to drill holes and CA a piece of nyrod into the hole. Use the yellow inner part. Your screws will not vibrate out, yet they are easy to remove.

judsterky

My Feedback: (4)

Campy,

That also sounds like a good technique, but it seems to me that the metal screws are causing the tiny cracks around the screw holes in the cowl that later on expands over time. Thats why I use the nylon screws. Do you have this problem?

David

MinnFlyer

My Feedback: (4)

I use Campy's method too. Works like a charm.

On larger planes where vibrations can cause the holes to enlarge (haven't had it happen on smaller ones so far) I just make the cowl holes a little larger and add a gromet, or a piece of fuel tubing in the hole.

judsterky

My Feedback: (4)

MinnFlyer,

Thanks for the idea and great illustraton of your technique, I might just try you and campys technique because after all its cheaper and just as fast.

Thanks,

David

TexasAirBoss

My Feedback: (22)

Always, always, always use maple ! It is the model builder's equal to steel . You won't strip the holes with maple !!

Campy

My Feedback: (1)

No, but I ALWAYS reenforce the inside of my cowl edge with a 2" strip of 2 oz fiberglass. I CA it in place with thin CA. Stiffens up the edge of the cowl and have not had any screws crack the cowl.

FWIW - I use the 7/16" socket head #2 screws by RTL. They take a 5/64" ball driver and have a built in washer. The final effect is more "professional" in appearance also.

saramos

Great tips. I too will be giving this method a try. The Spit I am building will have an RCV engine which generates a lot of vibes.

Scott