surface wing repair
- Thread starter stinson6
- Start date
Dan Cullman
New member
Cracks? In the wood skin? They must be addressed before refinishing the wood structure and recovering.
Get some competent help. I think the "Club," EAA and FAA AC 43-13 have some info for you.
The plywood skin on Bellanca wings is Structural and must be in good condition.
Dan
Get some competent help. I think the "Club," EAA and FAA AC 43-13 have some info for you.
The plywood skin on Bellanca wings is Structural and must be in good condition.
Dan
Thanks Dan but no, there are no cracks in the wood. Cracks are in the paint and I carefully sanded them down to the silver. I was told to just fill with more silver then sand smooth but I think it will just develop another crack down the line. Was just wondering what the experienced have done. By the way, the wings were checked and look great.
Dan Cullman
New member
Do you know the material that you are sanding? The wing does flex in service and a hard, brittle coating
can crack in time. Make sure that whatever you topcoat with later is compatible with the underlying
coating.
When you are sanding make sure you don't sand through the fabric.
Dan
can crack in time. Make sure that whatever you topcoat with later is compatible with the underlying
coating.
When you are sanding make sure you don't sand through the fabric.
Dan
blimpy
New member
wrote a long answer that got eaten and disappeared
Gist of which was:
Get professional inspection to insure wood structure is sound FIRST.
Following is for cosmetic filling and water proof sealing of cracked doped and painted fabric over plywood only.
Not for heat shrunk fabric elsewhere on the plane !!
Carefully sand paint and layers of dope to find out if fabric is intact. Don't damage the fabric .
do this so you can learn to determine fabric condition for all cracked areas.
Repair dope through silver where you test like this.
Point is to learn so you don't do this everywhere there is a crack in the paint.
Dope will NOT fill paint cracks.. too thin, too soft, and solvents upset the paint.
For cracks in paint over sound fabric.. I have good results with West System Flexible Epoxy.
I think the product number is 323. I will post correct number soon.
Read Product Application sheet carefully.
You want to apply a thin layer to Fill and Seal.
Temp of Epoxy and The Wing Skin is important. Use hot pad or electric blanket and thermometer if needed.
Avoid High Humidity, cold temps.
Mix and temp is more critical with thin applications ( see data sheet).
Experiment on plywood or stiff cardboard in the hanger environment you are working in.. not at home to get mix and application right.
Work in small batches, and on small areas only. Working time is not long.
Throw out epoxy if it gets too thick to spread easily.
apply with a plastic squeegee type applicator used with bondo ( auto paint store).
Apply with as little excess as possible to save feather sanding .
This will bond well, takes paint well ( even spray cans)
Airworthy as soon as it cures, without paint.
Stands all manner of stress caused by fluctuations in temperature and humidity acting on wooden wing skins.
I have patches a year old, both painted and un-painted that have gone through temps 120+ to sub freezing, and very high and low humidity.. no problem. I wouldn't expose to UV / Sun for long periods without paint, but see data sheet .. I just don't know about UV. In general I think it takes years for Sunlight to harm bare epoxy.. but it will.
Epoxy is very resistant to all common solvents, fuel, and etc.
Feather sand and paint for an "invisible" cosmetic fix, that should extend the life of your wings
until recover is truly necessary, by maintaining the water tight integrity of the coating system.
Gist of which was:
Get professional inspection to insure wood structure is sound FIRST.
Following is for cosmetic filling and water proof sealing of cracked doped and painted fabric over plywood only.
Not for heat shrunk fabric elsewhere on the plane !!
Carefully sand paint and layers of dope to find out if fabric is intact. Don't damage the fabric .
do this so you can learn to determine fabric condition for all cracked areas.
Repair dope through silver where you test like this.
Point is to learn so you don't do this everywhere there is a crack in the paint.
Dope will NOT fill paint cracks.. too thin, too soft, and solvents upset the paint.
For cracks in paint over sound fabric.. I have good results with West System Flexible Epoxy.
I think the product number is 323. I will post correct number soon.
Read Product Application sheet carefully.
You want to apply a thin layer to Fill and Seal.
Temp of Epoxy and The Wing Skin is important. Use hot pad or electric blanket and thermometer if needed.
Avoid High Humidity, cold temps.
Mix and temp is more critical with thin applications ( see data sheet).
Experiment on plywood or stiff cardboard in the hanger environment you are working in.. not at home to get mix and application right.
Work in small batches, and on small areas only. Working time is not long.
Throw out epoxy if it gets too thick to spread easily.
apply with a plastic squeegee type applicator used with bondo ( auto paint store).
Apply with as little excess as possible to save feather sanding .
This will bond well, takes paint well ( even spray cans)
Airworthy as soon as it cures, without paint.
Stands all manner of stress caused by fluctuations in temperature and humidity acting on wooden wing skins.
I have patches a year old, both painted and un-painted that have gone through temps 120+ to sub freezing, and very high and low humidity.. no problem. I wouldn't expose to UV / Sun for long periods without paint, but see data sheet .. I just don't know about UV. In general I think it takes years for Sunlight to harm bare epoxy.. but it will.
Epoxy is very resistant to all common solvents, fuel, and etc.
Feather sand and paint for an "invisible" cosmetic fix, that should extend the life of your wings
until recover is truly necessary, by maintaining the water tight integrity of the coating system.