ZT 400 stripping. How do I get the coating off without hurting the ?rubber?

Sillyship · Feb 9, 2016

I had been trying to sell this thing but then it grew on me and I want to keep it. I don't know why they coat aluminum handles, they can't rust, so what's the purpose? Because that coating isn't gonna stay on, it's gonna chip and scratch so why do it? Is it because they think aluminum is ugly? Aluminum has a very limited patina palette, but it can be colored and looks rather nice when it is.

Anyway, I want to strip this thing but I'm not sure what effect the epoxy/paint remover will have on the rubber parts that are inset on one side of the handle. Does anyone have any advice or suggestions?

I'd also like to replace those insets with something a bit more classy and/or permanent like wood or a custom made resin material etc. I've seen a bunch of vids on youtube showing how to DIY custom knife scales.

One of the things I've been building up to doing, is customizing my production blades. Some of them are close to perfection, but not quite there. A nip here a tuck there and voila, a masterpiece. I'm a skilled craftsman and this type of small detail work is just up my alley. I have the tools work shop and skills, just not sure what course to take. Any advice is appreciated.

Lastly, if any of y'all know of folks who make a hobby of this sort of thing, customizing (not just annodizing, or changing the scales, but actually changing the knife) production knives, I'd like to be hooked up with them. The few folks I know who do it, like socal knife customization (crawler something on youtube) are making a business of it so may not be open to sharing info. I'm too afraid to ask them anyway.

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REK Knives · Feb 9, 2016

I would disassemble, use a paint stripper, and clean it off with a Scotch brite pad. This will remove the coating. Oh, and I specialize in blade work although I do other stuff (NOT scale making though hehe) if you have something in mind.

Sillyship · Feb 9, 2016

razor-edge-knives said:
I would disassemble, use a paint stripper, and clean it off with a Scotch brite pad. This will remove the coating. Oh, and I specialize in blade work although I do other stuff (NOT scale making though hehe) if you have something in mind.

Nice work, you are now on my list. I still have to look at that google page more.

So, yeah, stripping it is easy, but what about those rubber parts?

REK Knives · Feb 9, 2016

Sillyship said:
Nice work, you are now on my list. I still have to look at that google page more.

So, yeah, stripping it is easy, but what about those rubber parts?

Not sure how to remove but the paint stripper won't harm rubber.

I would try heating in an oven which could loosen the epoxy holding them in place, then remove that way (if you will be replacing)

Sillyship · Feb 9, 2016

Thanks dude, that's some good advice. I didn't think the stripper would affect the rubber, but of course I will test a small portion first. Looking forward to trying this, thanks for your friendly advice.

killgar · Feb 9, 2016

Before you use a paint stripper you should check first to find out if it is suitable for aluminum. Paint strippers can contain some pretty strong/corrosive chemicals. Unless you want to risk etching, or discoloring the aluminum, you should do some thorough research first on what you're going to use. I once caused discoloration on an aluminum motorcycle wheel just using an automotive wheel cleaner, and it was a lot less corrosive than paint stripper.

Also, not all rubber is the same. I don't know what rubber that knife has in it's handles, but if paint stripper will burn skin, it might very well melt that rubber. Some rubber is resistant to chemicals, and some rubber will melt when it comes into contact with certain chemicals.

Furthermore, the paint stripper might have an affect on the glue that holds the rubber down. So even if the stripper doesn't affect the rubber, it might dissolve the glue.

As for the question of why knife makers put coatings on aluminum handles, one reason might be that aluminum can corrode.

Sillyship · Feb 9, 2016

Hmmmmm, good advice, but your answer to the possible reason of coating aluminum is the most intriguing. I didn't think of the possibility of the aluminum corroding.

nick_30 · Feb 9, 2016

Aluminum will create a whiteish powder when it corrodes and will pit

Rapt_up · Feb 11, 2016

The "coating" on the aluminum is commercial hard anodizing (not mil spec) with a dye added after to give it colour. its a thickened layer of aluminum oxide grown under special conditions (acid bath and electricity).

There are a number of commercial etch solutions that remove it without any sanding. BE aware the traction inserts are likely just bonded in with a 3M or similar adhesive (like super tape) and should come out with some gentle heating. and cen be replaced after stripping. stripping with chemicals will likely cause them to come out because they will be bonded to the anodized layer and if you dissolve that then they aren't bonded to anything, even if the chemicals don't hurt the rubber itself.

Some sweet Blurs etc where the rubber inserts were replaced with handmade CF or silver twill inserts. you could do something similar here. Or just glue the rubber back in after stripping.

As for why anodize? its way way harder than plain aluminum which is very soft, and will rub off on clothes, your hands etc as a grey smudge material. Its not terribly healthy either. Finally plain aluminum with steel will cause a galvanic reaction that essentially corrodes or rots the aluminum away to nothing in the presence of steel (iron) and moisture or salt... (like sweat for instance.)

Sillyship · Feb 11, 2016

Rapt_up said:
The "coating" on the aluminum is commercial hard anodizing (not mil spec) with a dye added after to give it colour. its a thickened layer of aluminum oxide grown under special conditions (acid bath and electricity).

There are a number of commercial etch solutions that remove it without any sanding. BE aware the traction inserts are likely just bonded in with a 3M or similar adhesive (like super tape) and should come out with some gentle heating. and cen be replaced after stripping. stripping with chemicals will likely cause them to come out because they will be bonded to the anodized layer and if you dissolve that then they aren't bonded to anything, even if the chemicals don't hurt the rubber itself.

Some sweet Blurs etc where the rubber inserts were replaced with handmade CF or silver twill inserts. you could do something similar here. Or just glue the rubber back in after stripping.

As for why anodize? its way way harder than plain aluminum which is very soft, and will rub off on clothes, your hands etc as a grey smudge material. Its not terribly healthy either. Finally plain aluminum with steel will cause a galvanic reaction that essentially corrodes or rots the aluminum away to nothing in the presence of steel (iron) and moisture or salt... (like sweat for instance.)

Thanks for that. I knew the inserts were prolly in with a rubber cement (3m) and I know about aluminum corrosion. However, I didn't think about aluminum scuff marks as a problem for edc knives or the corrosion issue. I really doubt the knife will corrode from just basic use. Especially not here in NM, but if I'm wrong please correct me. But, I might consider a thin coating of an epoxy clear coat or a basic enamel clear coat after I patina the aluminum.

All in all, it seems like my immediate response to aluminum knives, which was "don't like 'em, don't buy 'em" was the right one for me. I don't know if this knife is worth working on.