anodized vs polished?

Hey, I'm a new climbing. I'm thinking of buying some petzl spirit express quickdraws, but I'm not sure whether to buy the anodized or the polished (non-anodized) express draws. A reviewer on one website said that the anodized draws rub off on the rope making it black and also coating the belayers hands. That seems like it would suck, but most people do not seem to complain about that. I was just wondering if anyone had any on advice on whether to buy andoized or polished aluminum spirit express draws and why?

Thanks!

vgallo502 wrote:Hey, I'm a new climbing. I'm thinking of buying some petzl spirit express quickdraws, but I'm not sure whether to buy the anodized or the polished (non-anodized) express draws. A reviewer on one website said that the anodized draws rub off on the rope making it black and also coating the belayers hands. That seems like it would suck, but most people do not seem to complain about that. I was just wondering if anyone had any on advice on whether to buy andoized or polished aluminum spirit express draws and why? Thanks!

It doesn't matter in the slightest. Anodizing aluminum creates a hard protective aluminum oxide coating over the softer aluminum alloy. It takes about once lowering through the draw to remove this aluminum oxide coating where the rope runs through the draws leaving you with exactly the same thing as the polished aluminum draws. Buy whatever you think looks prettier.

As far as making the rope black and coating the belayers hands goes, any draw will do that whether it's annodized or not.

If you are OCD and want a clean rope then the best option is to make sure to use steel carabiners for the two carabiners that the top rope runs through.

In general, most people don't care. The anodized versus polished is pure looks and a personal preference.

They are all anodised anyway, just the `polished´one is anodised silver.

New spirits are coming out in January as well. Just an FYI.

kennoyce wrote: It doesn't matter in the slightest.

The anodized coating applied to climbing gear is absolutely critical in environments where the gear will come into contact with salt water, salt spray, or other chlorides. As long as the anodized coating stays intact, it effectively eliminates exfoliation corrosion on climbing gear when it is used in a marine environment (less direct prolonged contact with sea water). Of course the key word is as long as it is intact.

So if you use your gear on a sea cliff, get the anodized coating, it is really important. If you dont, do as you like. But if they both cost the same, there really is not any reason not to get it unless you really dont like the color.

So who actually makes non-anodised karabiners then, the last one I saw was made in about 1976.

20 kN wrote: The anodized coating applied to climbing gear is absolutely critical in environments where the gear will come into contact with salt water, salt spray, or other chlorides. As long as the anodized coating stays intact, it effectively eliminates exfoliation corrosion on climbing gear when it is used in a marine environment (less direct prolonged contact with sea water). Of course the key word is as long as it is intact. So if you use your gear on a sea cliff, get the anodized coating, it is really important. If you dont, do as you like. But if they both cost the same, there really is not any reason not to get it unless you really dont like the color.

There is just so much wrong with this post, but at least anyone who has any idea about what anodizing is will know that by 4 words into it.

An annodized coating is not applied to a biner, rather anodization is a process of passing an electrical current through the aluminum (which acts as an anode) to increase the thickness of the natural aluminum oxide layer on the surface of the aluminum. You are right that this helps with corrosion resistance, but it won't help much in a marine environment.

Again, as I had already mentioned, lower through an anodized biner once and you've most likely worn through the protective aluminum oxide layer leaving you with un-anodized aluminum which is now suceptable to exfoliation corrosion. The key to avoid this corrosion is not anodization, but to wash your gear after using it in a marine environment.

To top this all off, as Jim Titt mentioned upthread, even the silver spirits are annodized, they just aren't dyed a pretty color so the point is moot anyway.

caughtinside wrote: He may have gotten the process wrong but he's correct about the rest of it. After three weeks in thailand my anodized biners still look in great shape. My non anodized ones were pretty pitted. I washed all my gear when I got home. I don't know what to say about the silver annodization... other than my non color anodized biners looked 10 years old after that trip. Sure, the rope running through the basket will wear off that bit, but the rope will keep running through there and won't pit the metal quickly.

Interesting, I'm just curious what kind of biners your non-anodized ones are. There is certainly a possibility that you have some biners that really weren't annodized. Personally, I'd want to wash all my biners, anodized or not, every day after climbing in Thailand.

kennoyce wrote: There is just so much wrong with this post, but at least anyone who has any idea about what anodizing is will know that by 4 words into it. An annodized coating is not applied to a biner, rather anodization is a process of passing an electrical current through the aluminum (which acts as an anode) to increase the thickness of the natural aluminum oxide layer on the surface of the aluminum. You are right that this helps with corrosion resistance, but it won't help much in a marine environment. Again, as I had already mentioned, lower through an anodized biner once and you've most likely worn through the protective aluminum oxide layer leaving you with un-anodized aluminum which is now suceptable to exfoliation corrosion. The key to avoid this corrosion is not anodization, but to wash your gear after using it in a marine environment. To top this all off, as Jim Titt mentioned upthread, even the silver spirits are annodized, they just aren't dyed a pretty color so the point is moot anyway.

That is correct, anodizing is not a coating that is "painted" onto the product, I did not mean to imply it was. And you are right that I am not an expert in anodizing science, but I dont need to be to know its benefits. Aside from the part about the coating, the rest of my post was accurate. I have lived and climbed in a serious marine environment for the last five years which gives me more experience and insight on marine related issues than most, and I can assure you that anodizing is critical to preventing exfoliation corrosion.

But don't take my word for it. Watch the video below from DMM.

dmmclimbing.com/news/2011/0…

Specifically pay attention to the parts at 6:15 and 7:15 where DMM's senior engineer proves that the anodized coating significantly reduces the effects of exfoliation corrosion.

You are correct that washing your gear is important, but an anodized layer is equally as important as is clearly proved in the video above. But also as you said, pretty much all biners are anodized now days anyway so it is of limited importance.

Thanks everyone for the insight. I think what was confusing me was the fact that the spirit draws were available for purchase either anodized or polished. If its true that both versions are actually anodized, and the only difference is the color (one being silver and the other blue/orange), yet they still differentiate the blue/orange one as anodized and the silver one as polished or 'bright'; that seems a little misleading to me, i.e. it seems to suggest that only the orange/blue draws are anodized. Regardless, it sounds like the consensus is that, anodized are not anodized, all aluminum carabiners will oxidize and render the rope black. Therefore, I think I've decided just to go ahead and get the newer anodized (orange/blue) spirit draws.

If you look at the specs for the Petzl polished karabiner lower down it says anodised.
The confusion is because in the anodising industry one of the finishes used is called bright polished which is a chemical treatment used to smooth the metal before it is clear (or coloured) anodised as opposed to more common clear anodising which leaves a more silvery appearance. When I worked in the architectural aluminium industry the clear polished was commonly used for stuff like shop-fronts as it was supposed to look more like stainless steel, a bit 1980´s though!

caughtinside wrote: I bought the biners around 2001-4. Non anodized spirits were pitted. Anodized gates looked mint. non anodized DMM truklips pitted. Anodized gates mint. BD anodized biners with silver solid gates mint. Gates likely anodized silver. Wash your gear every day in thailand? You climb on it every day. No one washes their stuff every day.

Interesting, I thought pretty much everything was anodized by then. I do seem to recal that back around that time fram you could get silver DMM prowires in either unanodized, or anodized for like $1 more, so maybe Petzl didn't start anodizing their silver spirits until later than that.

As far as washing gear every day, I'm not talking about a thorough washing, I'm just talking a quick rinse in the evening to get most of the salt off the biners. I'm not saying that this is what people normally do, but I'd want to personally.

kennoyce wrote: There is just so much wrong with this post, but at least anyone who has any idea about what anodizing is will know that by 4 words into it. An annodized coating is not applied to a biner, rather anodization is a process of passing an electrical current through the aluminum (which acts as an anode) to increase the thickness of the natural aluminum oxide layer on the surface of the aluminum. You are right that this helps with corrosion resistance, but it won't help much in a marine environment. Again, as I had already mentioned, lower through an anodized biner once and you've most likely worn through the protective aluminum oxide layer leaving you with un-anodized aluminum which is now suceptable to exfoliation corrosion. The key to avoid this corrosion is not anodization, but to wash your gear after using it in a marine environment. To top this all off, as Jim Titt mentioned upthread, even the silver spirits are annodized, they just aren't dyed a pretty color so the point is moot anyway.

Actually, you both are correct. MIL-A-8625 revision F (governs many anodize processes) refers to anodize as "the applied coating" more than a dozen times and "coating" over 100 times. It is immersed in a bath of chromic acid. The reaction provides an exchange which (sometimes) includes the "application" of a dye which is a coating. The is a huge increase in corrosion protection in marine environments as indicated by 4.5.3. In short, an anodized aluminum will be more abrasion resistant as well as corrosion resistant.

David Peterson wrote: Actually, you both are correct. MIL-A-8625 revision F (governs many anodize processes) refers to anodize as "the applied coating" more than a dozen times and "coating" over 100 times. It is immersed in a bath of chromic acid. The reaction provides an exchange which (sometimes) includes the "application" of a dye which is a coating. The is a huge increase in corrosion protection in marine environments as indicated by 4.5.3. In short, an anodized aluminum will be more abrasion resistant as well as corrosion resistant.

Nice informative post guys - thanks!

Hi. I work at an anodizing facility, Chem Processing. Some of the commenters are correct. The "silver" is simply clear or undyed. The colored finish is dyed. To form the protective layer, the aluminum is submerged in sulfuric acid (someone mentioned chromic, but that is not used much any more). The oxide film penetrates into the material and grows outward in roughly equal proportions. Immediately after the process is performed, the coating has open pores which are filled by the dye if that is the next step. The final step is either a boiling water dip, which closes the pores, or a nickel acetate dip, which seals the pores. The coating is very hard. It is doubtful that it is rubbing off or through.

Anodizing can lower the fatigue strength of aluminum, which is of great concern in aerospace applications, but for most climbing applications it is not an issue. The pitting described in one of the replies would probably be of more concern. It is weakening the aluminum. Thus the anodizing process is more than just a matter of aesthetics.