Quick answer: I have successfully used a file cleaner.
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Long boring answer:
I had been cleaning my Home A/C outside condenser unit for years with a a water hose and spray head. Then I go to do what I had done for years with a new spray head and I was (not) thinking "Wow this new spray head is really getting this sucker clean!" When I was finished and had wiped all the water off of my glasses I could clearly see that what I thought was clean, really was that I had blasted all the fins over flat!.
Not in just a few places but over 90% all around condenser.
I tried the plastic combs with no real luck and tried lots of other things as well.
Finally I found something that worked, although I had to remove the outside large opening grill to properly get at the fins.
A file card. In my case a
Colton's No. 10 file cleaner. At the very bottom there was a 1/2 or so of unbent fins, I was able to get the end of card pressed in and as I pulled up it was straightening the fins. It did take a considerable amount of force to pull it up and very quickly the metal handle broke and the softer backing behind the the short steel wires started sliding out of the crimped steel holding it place. I had to take the card and tighten the crimping down with a hammer all the way around and and then bend the top edge where the handle used to be out at a 45 degree angle and latch a vise grip on it. After those modifications I was able to press in the bottom half of the card and then pull it straight up with the vise grips maintaining pressure against the card with my other hand. I worked great all the way around the condenser. I spent more time modifying the card than I did straightening the fins. Getting the outside grill back on was a major pain in the *** and If I had to do it again I'd modify the card even more so it would fit between the openings in the outside grill. Unfortunately Colton's doesn't make these any more (although available used on eBay for a premium) and I totally destroyed mine in the process. Now if I needed to do this again, I'd buy a wood handled one and find some way to reinforce the attachment to the wood (soak backing with super glue?) cut off the hand grip and fasten a metal handle to the wood backing bent out at an angle for hand clearance. I warned you it'd be boring.
After thought: One might also try a contour gauge if there are nearby undamaged fins that can be used to set it up and then drag down or up to straighten the fins? I think I recall trying mine with steel pins without success, but perhaps the newer plastic ones might work?
