The Cessna 120-140 Association Forum

Hello all, As our youth group makes progress on the restoration of our C140, we have started re-skinning the left elevator. Skin was in bad shape and non-conformity skin repair was installed. The matter in question is the stiffener that appears to be friction/spot welded to the skin. Looks to be the original factory configuration. We received new skins from Univair and as you would expect, no stiffener installed. Are these normally re-installed with rivets or how are most of the fleet configured? Thanks for your thoughts.

My 140 has both. The right one has the spot welds and the left has a rivet. Without diving into the logs, I think the left was a repair and the right is original. Someone more knowledgeable will have to comment which is better/original. A rivet might be easier to install.

Thanks for the reply. Yes, seems to be no other data on this. Our left elevator will have new skins with riveted stiffness. The right will be spot welded.

Spot welds on different skin areas on the Cessna 140 and 170 series was quite common and utilized by the factory when these aircraft were manufactured. Spot welding of aluminum skins was more cost effective for the factory and quicker than the costs of installing a rivet both in man-hour labor and materials. Some of our friends in the Cessna 170 community association have tried to replicate spot welding, but the costs of the welding equipment for a one time skin replacement is far more expensive than using rivets to replace a corrugated skin sheet. I've seen some beautiful work on replacement skins that have been riveted. If you are ever in need of another corrugated skin you might consider also contacting Karl Anderson up in Washington state. Karl makes excellent skins that I've found to be better than the Cessna originals.
https://www.aircraftnorthwest.com/

Thanks for the info on spot welds and a source for skins. I have the Univair units now and installation in process.