I have a Colt Gold Cup .22, the one made by Walther.
Its a good gun and I have thousands of rounds through it and with Mini Mags it has always run like a top. Last week I gave it to a local smith for a trigger job and as part of the trigger job he performed a detailed strip and cleaning.
The trigger job is excellent, right about 3.5 lbs and very clean. Worth the money. However, when I got the gun home and looked at it more closely I noticed that the finish on the frame, safety, slide stop, hammer and grip safety was badly faded and in some places nearly gone.
It almost looks as if a brand new slide was mounted on a 65 year old frame. I called the guy and asked what he used to clean it. He stated he used Hoppes #9 soaked in a rag to wipe down the gun. When he said he used Hoppes I nearly shit a brick! I stopped using Hoppes many years ago after hearing about situations where it dissolved certain finishes. The guy could tell I was pissed and he made good. He agreed to pay to have the frame Cerakoted by another smith we both know.
I'm still super pissed. I know the guns not an actual Colt, its just marked as such even though its a Walther product. Still, I would hope that Walther would have applied a finish that would be a little more tolerant of solvents. Anybody have similar issues?
I'll include some photos when I have a chance to upload them.

I'm assuming the discolored parts are zinc alloy?

My 10/22 suffered the same fate.  Hoppes #9 peeled the painted-on finish right off.  Really pissed me off.

Hoppes #9 is a barrel/chamber cleaner NOT a weapon wipe down rust preventative. I would hope a gun smith would know that.

The walther umarex guns while they may work pretty well are still a cheaply made gun with cheap material and a cheap finish - this does not surprise me in the least

Yeah, no shit! Seems pretty obvious.

See, back when firearms were made of steel alloys and had a blued or parkerized finish, it didn't matter.  Now that they are made of pot metal, styrofoam and Krylon,  need to be careful about such things.

At least he made good about it.

I know people who use #9 as their lube too

Occasionally I'll see someone say they use it as a lube here on the forums too.

Wtf

Hoppes No. 9 includes at least two products.  There is a bore solvent and a lubricating oil.

Using that bore solvent as a general surface cleaner on a delicately finished pot metal Umarex or GSG gun is a mistake I would not expect a gunsmith to make, but that's why I clean my own guns.

The mistake is that companies with name recognition hire pellet gun and airsoft gun companies to make a product out of zinc and then put the "name" on the thing.

The mistake2 (meaning squared) is that any of us buy guns that are not made out of blue steel and wood (or at least Glock's plastic).

My S&W branded M&P BB pistol is made of better materials than the "real guns" Umarex sells branding for "names"  although probably made by the same German company.

I would never dream of using Hoppe's #9 on a zinc gun because I would never dream of buying a zinc gun.  Sorry for your frustration.

Hoppes 9 work great as a light oil to prevent rust. After wiping down a firearm with it, the solvent evaporates leaving a light uniform coat of oil. The solvent gets the oil in places that are nearly impossible with just an oil. It is not a replacement of a good oil for parts that wear on each other.

I have a GSG 22 1911, and the finish is crap. I know not to use anything except Ballistol oil on it. This stuff does everything, and it the best I have found for gun bore cleaning as well. I hardly use Hoppes #9 anymore. Anyway, the finished on the zinc alloy guns is crap and I'm frustrated they can't put a better one on them. BUT, my GSG 1911 22 is accurate, reliable, and fun to shoot, and for the money I paid I am more than happy with it.  It goes to the range with me every time.