rust-prevention tests
Jun 18, 2013 5:16:48 GMT
Post by Lord Cobol on Jun 18, 2013 5:16:48 GMT
I'm still in the noob stage of swords and rust prevention, reading up and curious about the different advice I read, so I decided a while back to do some tests.
I took 2 identical dull machetes, removed the old oil (using 91% alcohol, then turpentine), used masking tape to divide each blade into 3 sections, and applied different rust treatments each section, two coats on consecutive days. Then I waited 3+months for the oil to evaporate, put a small amount of water near the middle of each section and a fingerprint near the edge, then started a daily of checking for rust, then re-applying a few drops tap water near the middle and sometimes adding fingerprints.
The 6 sections were treated with:
1: 3-in-1 oil,
2: mineral oil (the thick laxative stuff, not the thin baby oil)
3: liquid wrench "super penetrant"
4: Johnson's paste wax (yellow tin, metal-safe)
5: cheap store brand vaseline / "petroleum jelly"
6: "nothing", as a control.
The 3-in-1, liquid wrench & vaseline were old stuff that I had sitting around for years, I think at least 30 years in the case of the vaseline. Liquid Wrench no longer carries the exact same product name.
All the coatings were thin, rubbed in like in my normal monthly cleaning and not visually obvious.
The machetes were Corona brand 24-inchers, $8.05 at a nearby garden supply store. Both came with small pits of black rust which are not part of this test, and which have not grown noticeably since I got them. (All the others of that brand in the store had pits too -- I picked the two best ones).
I hope cat-hair doesn't promote rust enough to invalidate the experiment, but the liquid wrench, vaseline & untreated sections probably had a cat tail resting on them a few times, and the untreated section may have been sat on.
The rust treatments were applied on 03-04-2013 & 03-05-2013. The water torture started on 06-12-2013. No rust formed just from the 3 months of sitting around.
The untreated and liquid-wrench sections showed intense water-spot-sized rust within a few hours. Epic fail for those two. I entombed those spots in thick globs of vaseline. Hmmm... could be a problem for any cat that sits there The poor performance of the liquid wrench is not a total surprise - I've read that wd40 evaporates too quickly to be a good rust preventer, and I'd guess that liquid wrench is in the same general category.
On day 5 of the water torture (6-16-2013) there were very small spots on the 3-in-1, wax and mineral oil sections, 1 spot each, where I had put water. Wasn't 100% sure they weren't blemishes that I missed before, so I made note of the size, added more water and continued.
By the evening of day 6, about 8 hours after the daily water dose, the spots in the mineral oil and 3-in-1 sections were larger (like pin-head size) and there were several new pin-prick sized spots in the wax section. Definitely rust. Only the vaseline showed nothing rust-like.
None of the finger-print locations showed any rust.
Preliminary conclusions:
1: fingerprints are not as immediately toxic as water.
2: 3-in-1, wax, vaseline & thick mineral oil are all good for at least 3 months in favorable conditions like indoors in dry southern California.
3: only the vaseline is up to 3 months of harsher conditions.
The big surprise / disappointment was the wax, because I have seen Johnson's recommended for rust prevention, and because I have seen Minwax non-metal-safe paste wax keep wood waterproof under light usage (think coathangers and wet sweatshirts) for over 10 years and counting.
The thick mineral oil was also a bit of a surprise, because I know from another rust test (not ready to post yet), that it takes forever and a day to evaporate.
I might continue the test a while, to see how long the vaseline lasts, and to see how long it takes for fingerprints to rust, but the important part of the test is over. Eventually at least one of the machetes gets repurposed for sharpening practice and then cutting practice. The other might get used for another round of tests.
I'm open to suggestions about what to test next. Tentatively I'll treat each section on 2 days, then start the water torture & fingerprints on the 3rd day instead of waiting 3 months. Possible subjects include the winner of the current test, light mineral oil from the baby section, and a hybrid. Since I have read that some people believe their rust prevention should include something that removes/disperses water, and the "wd" in wd40 stands for "water dispersal", I'm thinking that one section might get wd40 on day 1 and some kind of oil on day 2.
The main purpose of this hypothetical next test would be to see how the oils stand up to harsh conditions for short periods. The current test with the 3-month wait is more relevant for long-term storage.
I took 2 identical dull machetes, removed the old oil (using 91% alcohol, then turpentine), used masking tape to divide each blade into 3 sections, and applied different rust treatments each section, two coats on consecutive days. Then I waited 3+months for the oil to evaporate, put a small amount of water near the middle of each section and a fingerprint near the edge, then started a daily of checking for rust, then re-applying a few drops tap water near the middle and sometimes adding fingerprints.
The 6 sections were treated with:
1: 3-in-1 oil,
2: mineral oil (the thick laxative stuff, not the thin baby oil)
3: liquid wrench "super penetrant"
4: Johnson's paste wax (yellow tin, metal-safe)
5: cheap store brand vaseline / "petroleum jelly"
6: "nothing", as a control.
The 3-in-1, liquid wrench & vaseline were old stuff that I had sitting around for years, I think at least 30 years in the case of the vaseline. Liquid Wrench no longer carries the exact same product name.
All the coatings were thin, rubbed in like in my normal monthly cleaning and not visually obvious.
The machetes were Corona brand 24-inchers, $8.05 at a nearby garden supply store. Both came with small pits of black rust which are not part of this test, and which have not grown noticeably since I got them. (All the others of that brand in the store had pits too -- I picked the two best ones).
I hope cat-hair doesn't promote rust enough to invalidate the experiment, but the liquid wrench, vaseline & untreated sections probably had a cat tail resting on them a few times, and the untreated section may have been sat on.
The rust treatments were applied on 03-04-2013 & 03-05-2013. The water torture started on 06-12-2013. No rust formed just from the 3 months of sitting around.
The untreated and liquid-wrench sections showed intense water-spot-sized rust within a few hours. Epic fail for those two. I entombed those spots in thick globs of vaseline. Hmmm... could be a problem for any cat that sits there The poor performance of the liquid wrench is not a total surprise - I've read that wd40 evaporates too quickly to be a good rust preventer, and I'd guess that liquid wrench is in the same general category.
On day 5 of the water torture (6-16-2013) there were very small spots on the 3-in-1, wax and mineral oil sections, 1 spot each, where I had put water. Wasn't 100% sure they weren't blemishes that I missed before, so I made note of the size, added more water and continued.
By the evening of day 6, about 8 hours after the daily water dose, the spots in the mineral oil and 3-in-1 sections were larger (like pin-head size) and there were several new pin-prick sized spots in the wax section. Definitely rust. Only the vaseline showed nothing rust-like.
None of the finger-print locations showed any rust.
Preliminary conclusions:
1: fingerprints are not as immediately toxic as water.
2: 3-in-1, wax, vaseline & thick mineral oil are all good for at least 3 months in favorable conditions like indoors in dry southern California.
3: only the vaseline is up to 3 months of harsher conditions.
The big surprise / disappointment was the wax, because I have seen Johnson's recommended for rust prevention, and because I have seen Minwax non-metal-safe paste wax keep wood waterproof under light usage (think coathangers and wet sweatshirts) for over 10 years and counting.
The thick mineral oil was also a bit of a surprise, because I know from another rust test (not ready to post yet), that it takes forever and a day to evaporate.
I might continue the test a while, to see how long the vaseline lasts, and to see how long it takes for fingerprints to rust, but the important part of the test is over. Eventually at least one of the machetes gets repurposed for sharpening practice and then cutting practice. The other might get used for another round of tests.
I'm open to suggestions about what to test next. Tentatively I'll treat each section on 2 days, then start the water torture & fingerprints on the 3rd day instead of waiting 3 months. Possible subjects include the winner of the current test, light mineral oil from the baby section, and a hybrid. Since I have read that some people believe their rust prevention should include something that removes/disperses water, and the "wd" in wd40 stands for "water dispersal", I'm thinking that one section might get wd40 on day 1 and some kind of oil on day 2.
The main purpose of this hypothetical next test would be to see how the oils stand up to harsh conditions for short periods. The current test with the 3-month wait is more relevant for long-term storage.