M20A Wing-Repair

[jst]

Thank's to the leaking hangar-roof I have to repair the top serface of the wood-wing, including the sealer of the woodsurface.

Does someone know the type of material they used ? Was it polyester-resign or epoxy-resign for soaking the fabric (what kind of fabric ? ) ?

 

thank's for Your inputs

 

[Sabremech]

Hi Jst,

I just picked up a 56 M20 model. I’m researching maintenance on this wood wing and may be able to provide you a bit of help in the near future.

Thanks,

David

[Pinecone]

Considering the time they were built, it is probably fabric and aircraft dope.

Clear to attach the fabric and seal the cloth, then silver for UV protection and then color.  Just like a fabric airplane.

[Fly Boomer]

2 hours ago, Pinecone said:

Considering the time they were built, it is probably fabric and aircraft dope.

Clear to attach the fabric and seal the cloth, then silver for UV protection and then color.  Just like a fabric airplane.

As I recall, clear to shrink the linen, silver for UV and to fill the warp and weft, followed by color coat.

[Pinecone]

Pretty much.

If synthetic fabric, shrink with heat and then clear.  

Either way, enough clear to fill the fabric.   Also, with linen, after shrinking, may use nitrate to limit more shrinking.

[Fly Boomer]

10 hours ago, Pinecone said:

Pretty much.

If synthetic fabric, shrink with heat and then clear.  

Either way, enough clear to fill the fabric.   Also, with linen, after shrinking, may use nitrate to limit more shrinking.

Ah, yes.  I had forgotten about the nitrate dope vs butyrate dope.

[kerry]

What part of the wing? The reason I ask is because if it's the wing walk area then it's not necessarily damage caused from a leaking roof.  It's caused from the many years of use.  If wood is damaged, then I would scarf in spruce plywood(I would use a thicker piece of spruce vs. the original thickness if it is the wing walk. T-88 epoxy  would be the best.  The original glue was formaldehyde based which is technically the legal stuff.  The original cotton has probably been replaced with Ceconite. Light weight uncertified unstamped Ceconite is what is used on wood surfaces.

[Jerry Pressley]

Man in Oklahoma has a wing hanging from his ceiling if it comes to that.  JerryP

[cliffy]

IF you use nitrate dope be very aware of its flammability!!!  Don't even think of smoking or open flames

anywhere near the work area

I once saw a Fairchild 24 wing go up in flames and smoke in about 2 mins when the wet nitrate dope

was torched off by someone smoking. 

Wood working and fabric on GA airplanes is a lost art. Not many do it today. If the wood under the compromised area is

itself compromised in any way I would suggest getting someone who knows and does a/c wood work to do the 

repair by the book. 

[Pinecone]

ALL dope is highly flammable.  Nitrate is much more flammable that butyrate after it dries.