Small dents - need PDR recommendations

[Yourpilotincommand]

I have a small dent in the leading edge near the wingtip and a small one on the cowl. They are minor cosmetics, but want to get these fixed. I’m in the north Texas area. Thanks!

[A64Pilot]

I’d honestly call the Auto guys, being in Tx I bet there are many as when I lived there hail wasn’t rare. It’s cosmetic as you say so in my opinion they don’t need to be A&P’s 

Then as crazy as this sounds but being out in the hot summer sun seems to make the dents diminish in size, I know that sounds nuts but I watched in on my VW back in 1980 when I worked in the oil fields.

I think I’d ignore them before I went the bondo and paint route myself.

If the dent in the leading edge can be accessed from the backside a good sheet metal guy might could “spoon” it out, surely could the the cowl

[0TreeLemur]

Isn't it true that PDR doesn't work on aluminum because if the metal deflects enough to permanently deform it strain hardens.  That changes the material properties.  They'll never get it back to where it was before, its a different material.   Maybe they can make it look a little better, but restoration like on a steel auto body isn't possible.

[Shadrach]

6 minutes ago, 0TreeLemur said:

Isn't it true that PDR doesn't work on aluminum because if the metal deflects enough to permanently deform it strain hardens.  That changes the material properties.  They'll never get it back to where it was before, its a different material.   Maybe they can make it look a little better, but restoration like on a steel auto body isn't possible.

I have two BMWs with aluminum skinned body panels.  I have been absolutely stunned by what a good PDR tech has been able to do. My guy was able to erase things that I would have thought impossible correct. It can be done but it is harder as aluminum has no memory unlike steel which has memory and is easily encouraged to return to its original shape.

[MikeOH]

7 minutes ago, 0TreeLemur said:

Isn't it true that PDR doesn't work on aluminum because if the metal deflects enough to permanently deform it strain hardens.  That changes the material properties.  They'll never get it back to where it was before, its a different material.   Maybe they can make it look a little better, but restoration like on a steel auto body isn't possible.

I'm by no means a metallurgist, but doesn't the same thing happen with steel?  From a 3D perspective the 'dimple' has to represent a 'stretching' of the metal past its elastic limit regardless of whether it is aluminum or steel; they both have been 'work' hardened.  Not sure what you mean by a 'different' material??

 

[0TreeLemur]

13 minutes ago, MikeOH said:

Not sure what you mean by a 'different' material??

I dunno, my first sentence was meant to have a question mark.   I've crushed a lot of beer cans, and boy are they hard to uncrush.   Some PDR people are absolute magicians.  Maybe you can find someone who can do it.

Aluminum stress-strain curves have a linear region at lower loading, then a nonlinear region before reaching ultimate strength.  Take the load off at this point, and it doesn't follow the exact same path back down the stress-strain curve- hysteresis.   So, load history can affect its behavior.  Kind of like what @Shadrach means when he used the term "memory".  I would speculate that it depends on how close it got to ultimate strength when deformed.  If not very close, PDR might just do wonders.   If close, probably not.  Post before/after pics when done!

 

[Shadrach]

It’s my understanding that cold working aluminum (or steel for that matter) strengthens the area where the metal was worked. It is also makes it harder and less flexible making it more prone to cracks if in an area that flexes.

[Pinecone]

The difference is, when you crush a beer can, you form folds and sharp creases.  Those are much harded to get out.

But that would be an interesting challenge, for a PDR person to uncrush a beer can.  I would not bet against some of the ones I have seen work.