Grasshopper109

HI every one,

I hope some one can help a mate of mine has just given me an engine cowl belonging to a cyclone pattern plane that was donated to him. Which needs the holes from a previous engine installation to be filled.

I have just completed a similar repair for another friends AT6 Texan which turned out great for my first go at fiberglassing. But this one has a large hole with compound curves to be filled.

the hole on the bottom is the one that I need help with.


[img][/img]

saramos

Perhaps you could carve and shape a foam plug that would fit inside the cowl. Then glass over the hole. Once done, remove the foam. You could use florest foam called Oasis. It is soft and very shapable.

rcalfred

You could also securely tape a piece of sheet balsa on the inside of the cowl. Then do the lay-up. From the picture it appears that there is a serious crack running through it. You'll want to be sure to cover the inside with glass cloth and then smooth the outside with more resin. Regards.

goony

it would be easier and quicker to make a new mold and part rather than fannying around with that and making it heavier


goony

Grasshopper109

hi goony,

I would love to make a whole new cowl from scratch but I think that might be beyond me at the moment. I think I might try and plug the hole from either the inside or out side and then lay it up.

I think for my first fiberglass cowl I might try one a bit simpler.

Countryboy

My Feedback: (25)

Use your existing hole as a guide. Tape a piece of 1/64 or 1/32 ply large enough to cover the hole you want to fill over the outside of the cowl and trace the pattern of the hole from the inside of the cowl onto the ply that you haved taped into place on the outside. Cut the ply 3/16" to 1/4" larger than the outline you drew. Sand the inside of the cowl and wipe down with alcohol or acetone...now CA the ply to the inside of the cowl. Now, cut a piece of 1/32 balsa to the shape of the hole and glue it to the ply from the outside of the cowl. Fill any voids between the balsa and glass cowl with a bondo glazing putty and sand the outside to conform to the cowl. Now, it's just a matter of glassing over the balsa and then sanding for final prep of primer & paint. You could also put a layer of glass over the ply on the inside to seal it in and get a better bond.

Hope I made the explanation clear enough. Basically, all you need to do is bridge the hole and back fill.

Grasshopper109

OK I now have the cowl all ready to be fiberglassed. I ended up plugging all the holes up from the outside with single ply cardboard that has been waxed and used 1.5mm ply soaked with ammonia to com-form to the compound curves which I then added 3mm reinforcing strips to and lined with plastic.

[img][/img]

Grasshopper109

Ok here is the pic I am only new to this.

jowily

My Feedback: (31)

HERE WAS MY FIRST HOME MADE COWL, IT IS A BIT HEAVY AND THICK BUT DID NOT HAVE A MOLD. BUT i WILL NEXT TIME.

I LIKE TO USE SAME MATERIAL TO PLUG A HOLE EXAMPL FIBERGLASS TO FIBERGALSLS

i WOULD HAVE LAID UP A SHEET OF FIBERGLASS LET IT CURE THEN MOLD IT TO THE INSIDE OF THE COWL WITH A HEAT GUN,(* BUT HAVE TO BE CAREFULL ) THEN EPOXIED IT TO THE COWL AND FILLED THE REMAINING WITH SOME MORE EPOXY AND SPOT PUTTY.


GO HERE TO SEE PIC http://home.comcast.net/~jrwillis2/w...D-2399550.html

Vortec

Im the mate that Grasshopper fixed the chin cowl for and im very pleased with it, as he done a far better job than i could of..Two thumbs up..