[skelrad]

I know when extending the edge of a fiberglass part, the thickness of the part gives you enough meat to make a scarf joint and create a good bond with the new fiberglass. Is there any difference when needing to extend the edge of a metal skin? For example, I'm kicking around the idea of extending the side skins of my tip up canopy to overlap the fuselage skin maybe 1/4". The thickness of a skin doesn't allow for much of a true scarf joint. Do you just have to roughen up a larger area of the skin and make a wider transition zone with multiple layers of glass (vs a small scarf joint that essentially cuts through the thickness of material and ultimately creates a flat transition with the new fiberglass layers)? How many layers is typical for something like this?

 

[penguin]

It is difficult to extend alumin(i)um with fiberglass. You will really struggle to get the resin to stick well to the metal.
Cut a new side skin from a flat sheet of metal.

 

[Brantel]

I know when extending the edge of a fiberglass part, the thickness of the part gives you enough meat to make a scarf joint and create a good bond with the new fiberglass. Is there any difference when needing to extend the edge of a metal skin? For example, I'm kicking around the idea of extending the side skins of my tip up canopy to overlap the fuselage skin maybe 1/4". The thickness of a skin doesn't allow for much of a true scarf joint. Do you just have to roughen up a larger area of the skin and make a wider transition zone with multiple layers of glass (vs a small scarf joint that essentially cuts through the thickness of material and ultimately creates a flat transition with the new fiberglass layers)? How many layers is typical for something like this?

I did this to my 7 and after over 10 years of flying it’s held up great! I used the entire skirt to bond the overhang to. You could also remove some screws and layup the glass then countersink for the screws and replace them.

The painted pic below was taken right before I sold the airplane.

 

[JonJay]

I wouldn’t. But I also believe the worst part of Vans design is how windscreen fairings are constructed, and there are thousands flying with zero issues.
I made metal fairings, but fiberglass fairings that are separate pieces work for me.
This is just me. Do what you’re comfortable with. However, if they ever start to fail you have a mess, which occasionally happens to windscreen fairings, cracking, delamination, etc….
Seen it.