Hoppes blast n shine damaged aluminum finish

SEHunter · November 27, 2019, 09:57 PM

(Edit: the receiver is steel, not aluminum. Didn’t realize it at first.)

Due to my own carelessness, i got some hoppes blast n shine on the aluminum receiver of a milled Arsenal AKM receiver. It streaked a spot and turned the white rag purple when i wiped it off. I dont know how the “blued” aluminum finish was done or what chemical is used on the aluminum to achieve the matte black/satin black coloring. Does anyone know of a product I could use to try to touch up or attempt to lessen the obviousness of the damaged part of the finish?

mehavey · November 27, 2019, 10:44 PM

You might look at this possibility (test first)
http://mossbergowners.com/forum/inde...-w-pics.11546/

SEHunter · November 28, 2019, 08:30 AM

Thanks for the link. Definitely will give this a try. Thanks

SEHunter · November 28, 2019, 10:00 AM

I’ve tried to research the finish on the receiver but haven’t been able to find exactly what it is. Gun is an Arsenal sam7r bought new in October this year. It may be some type of paint. If so, I'm guessing the product noted above isn’t for this application, it seems to be designed for use on clean aluminum. If anyone is familiar with the finish on the Arsenal receiver, I’d appreciate the info.

**44 AMP** · November 28, 2019, 01:30 PM

I have no idea what they used on your AKM but generally the process used on aluminum is anodizing, which is a kind of electroplating process, and completely different from the bluing used on steel which is a controlled rust process.

**Unclenick** · November 28, 2019, 01:59 PM

Anodizing uses a sulfuric acid solution and a direct electric current to build up a hard aluminum oxide layer on the aluminum surface that is transparent and porous. The part is then put in a dye that is absorbed into the pores to provide whatever color is desired, and then it is sealed. It sounds like the solvent got past the sealant and dissolved some of the dye. That can happen if the dichromate sealing method was used. I don't know if this can be repaired short of complete refinishing. In theory, the old finish can be removed in a sulfuric acid solution by reversing the current flow. Once gone, the part can be bead-blasted and refinished, including being dyed and sealed anew, but I've not tried it. I would consult the manufacturer.

Bill DeShivs · November 28, 2019, 02:09 PM

Show us a good picture of the area. Anodizing vs paint is easy to spot.

SEHunter · November 28, 2019, 06:58 PM

I think Unclenick hit the nail on the head. The liquid ran off purple. If i rub an inconspicuous spot on the receiver with rubbing alcohol, a faint purple color appears on the white paper towel.

Bill D, Im trying to upload a picture but unfortunately at the moment the download keeps failing. Ill try again shortly.

Dfariswheel · November 28, 2019, 08:58 PM

A lot of foreign military rifles are painted with a black paint that when it contacts a solvent it comes off purple.

You see this a lot on imported AK rifles.

I don't know what kind of paint it is, it looks black but come off with solvent as purple.
I found this out in the 60's when I dropped a part in a container of lacquer thinner to clean a surplus rifle and the thinner turned purple.

I've most recently seen this with a Bulgarian SLR-96 and a Bulgarian AK-74 built from an unfired surplus demilled rifle.

kozak6 · November 29, 2019, 07:02 AM

Arsenal AK's are famous for their fragile paint. It's not anodizing, as it's a steel receiver. Tickle it with a magnet if you'd like to check.

Head over to akfiles.com to ask about it. It's possible to buy expensive Russian-spec paint, and there's various appliance paints that match up fairly well.

SEHunter · November 29, 2019, 07:55 AM

You’re right, im not sure why I assumed it was aluminum. The milled receiver is definitely a magnetic metal, just checked.

SEHunter · November 29, 2019, 08:08 AM

I cant get the picture to load. I think I understand my options now. I’ll either just get over it or take to get cerakote or something. I browsed on akfiles.com and it’s common. Its nearly baffling to me why any modern firearm maker in any country would use such a fragile finish. Surely there’s something as cheap that is better.

Thanks to all who contributed here. Happy Thanksgiving.

T. O'Heir · December 1, 2019, 02:20 PM

"...a product I could use..." Birchwood Casey makes Aluminium Black. Comes in a bottle(3 ounces for $12.99) that's used just like cold bluing. Or a pen($7.99) that's used just like a Sharpie.
Of course, regular cold bluing will fix ferrous metal finishes.

SEHunter · December 1, 2019, 05:42 PM

Appreciate the lead. Unfortunately I’ve found this receiver is not aluminum and the bulgarian mfg uses a 2 step coating. They apply some form of blue or park to the milled receiver, then its painted with some type of super cheap paint that is sensitive to most all chemicals and solvents besides mild gun oils.

**Unclenick** · December 3, 2019, 11:39 PM

Zinc Parkerizing is porous and makes a great adhesion base for paints. You can get the old finish off with Iosso's bluing and phosphate finish remover, but then you want to re-Park and paint again with something more durable that will match the old color. This YouTube video may help you make a choice.

SEHunter · December 4, 2019, 05:53 AM

Thanks for that link! May be the route i go

November 27, 2019, 09:57 PM	#1
SEHunter Senior Member Join Date: October 6, 2009 Posts: 332	Hoppes blast n shine damaged aluminum finish (Edit: the receiver is steel, not aluminum. Didn’t realize it at first.) Due to my own carelessness, i got some hoppes blast n shine on the aluminum receiver of a milled Arsenal AKM receiver. It streaked a spot and turned the white rag purple when i wiped it off. I dont know how the “blued” aluminum finish was done or what chemical is used on the aluminum to achieve the matte black/satin black coloring. Does anyone know of a product I could use to try to touch up or attempt to lessen the obviousness of the damaged part of the finish? Last edited by SEHunter; November 29, 2019 at 08:12 AM.

November 28, 2019, 01:30 PM	#5
44 AMP Staff Join Date: March 11, 2006 Location: Upper US Posts: 28,833	I have no idea what they used on your AKM but generally the process used on aluminum is anodizing, which is a kind of electroplating process, and completely different from the bluing used on steel which is a controlled rust process. __________________ All else being equal (and it almost never is) bigger bullets tend to work better.

November 28, 2019, 01:59 PM	#6
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	Anodizing uses a sulfuric acid solution and a direct electric current to build up a hard aluminum oxide layer on the aluminum surface that is transparent and porous. The part is then put in a dye that is absorbed into the pores to provide whatever color is desired, and then it is sealed. It sounds like the solvent got past the sealant and dissolved some of the dye. That can happen if the dichromate sealing method was used. I don't know if this can be repaired short of complete refinishing. In theory, the old finish can be removed in a sulfuric acid solution by reversing the current flow. Once gone, the part can be bead-blasted and refinished, including being dyed and sealed anew, but I've not tried it. I would consult the manufacturer. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

November 28, 2019, 02:09 PM	#7
Bill DeShivs Senior Member Join Date: April 7, 2006 Posts: 10,985	Show us a good picture of the area. Anodizing vs paint is easy to spot. __________________ Bill DeShivs, Master Cutler www.billdeshivs.com

December 1, 2019, 02:20 PM	#13
T. O'Heir Senior Member Join Date: February 13, 2002 Location: Canada Posts: 12,453	"...a product I could use..." Birchwood Casey makes Aluminium Black. Comes in a bottle(3 ounces for $12.99) that's used just like cold bluing. Or a pen($7.99) that's used just like a Sharpie. Of course, regular cold bluing will fix ferrous metal finishes. __________________ Spelling and grammar count!

November 27, 2019, 10:44 PM	#2
mehavey Senior Member Join Date: June 17, 2010 Location: Virginia Posts: 6,894	You might look at this possibility (test first) http://mossbergowners.com/forum/inde...-w-pics.11546/

November 28, 2019, 08:30 AM	#3
SEHunter Senior Member Join Date: October 6, 2009 Posts: 332	Thanks for the link. Definitely will give this a try. Thanks

November 28, 2019, 10:00 AM	#4
SEHunter Senior Member Join Date: October 6, 2009 Posts: 332	I’ve tried to research the finish on the receiver but haven’t been able to find exactly what it is. Gun is an Arsenal sam7r bought new in October this year. It may be some type of paint. If so, I'm guessing the product noted above isn’t for this application, it seems to be designed for use on clean aluminum. If anyone is familiar with the finish on the Arsenal receiver, I’d appreciate the info.

November 28, 2019, 06:58 PM	#8
SEHunter Senior Member Join Date: October 6, 2009 Posts: 332	I think Unclenick hit the nail on the head. The liquid ran off purple. If i rub an inconspicuous spot on the receiver with rubbing alcohol, a faint purple color appears on the white paper towel. Bill D, Im trying to upload a picture but unfortunately at the moment the download keeps failing. Ill try again shortly.

November 28, 2019, 08:58 PM	#9
Dfariswheel Senior Member Join Date: May 4, 2001 Posts: 7,478	A lot of foreign military rifles are painted with a black paint that when it contacts a solvent it comes off purple. You see this a lot on imported AK rifles. I don't know what kind of paint it is, it looks black but come off with solvent as purple. I found this out in the 60's when I dropped a part in a container of lacquer thinner to clean a surplus rifle and the thinner turned purple. I've most recently seen this with a Bulgarian SLR-96 and a Bulgarian AK-74 built from an unfired surplus demilled rifle.

November 29, 2019, 07:02 AM	#10
kozak6 Senior Member Join Date: June 16, 2005 Location: AZ Posts: 3,113	Arsenal AK's are famous for their fragile paint. It's not anodizing, as it's a steel receiver. Tickle it with a magnet if you'd like to check. Head over to akfiles.com to ask about it. It's possible to buy expensive Russian-spec paint, and there's various appliance paints that match up fairly well.

November 29, 2019, 07:55 AM	#11
SEHunter Senior Member Join Date: October 6, 2009 Posts: 332	You’re right, im not sure why I assumed it was aluminum. The milled receiver is definitely a magnetic metal, just checked.

November 29, 2019, 08:08 AM	#12
SEHunter Senior Member Join Date: October 6, 2009 Posts: 332	I cant get the picture to load. I think I understand my options now. I’ll either just get over it or take to get cerakote or something. I browsed on akfiles.com and it’s common. Its nearly baffling to me why any modern firearm maker in any country would use such a fragile finish. Surely there’s something as cheap that is better. Thanks to all who contributed here. Happy Thanksgiving.

December 1, 2019, 05:42 PM	#14
SEHunter Senior Member Join Date: October 6, 2009 Posts: 332	Appreciate the lead. Unfortunately I’ve found this receiver is not aluminum and the bulgarian mfg uses a 2 step coating. They apply some form of blue or park to the milled receiver, then its painted with some type of super cheap paint that is sensitive to most all chemicals and solvents besides mild gun oils.

December 3, 2019, 11:39 PM	#15
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	Zinc Parkerizing is porous and makes a great adhesion base for paints. You can get the old finish off with Iosso's bluing and phosphate finish remover, but then you want to re-Park and paint again with something more durable that will match the old color. This YouTube video may help you make a choice. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

December 4, 2019, 05:53 AM	#16
SEHunter Senior Member Join Date: October 6, 2009 Posts: 332	Thanks for that link! May be the route i go