Today Vuurwapen Blog posted the first round of results from the lab testing I performed last week. Now that people have had a chance to see the data, here’s my interpretation of it. Please note that while data doesn’t change, interpretations may vary based on your past education and experience (a PhD would likely interpret this data a little bit differently than an undergraduate student like myself).
I’m not a writing major or anything like that, so I’m going to use the format I know: lab reports
Please note that all images can be opened in a new tab and enlarged. The formatting is giving me trouble, but I’m a chemist, not a computer person…
Procedure: All data for this comparison was taken on a Perkin Elmer Spectrum One FT-IR Spectrometer with Universal ATR Sampling Accessory. More detailed procedures are described in my previous post
The samples were different brands of CLP with different years of manufacture, listed from oldest to newest as follows:
#15: Royal Lubricants Co CLP, manufactured March of 2000
#10: Otis CLP, manufactured approximately 2005
#14: Break-Free aerosol CLP, purchased 2010
#5: Break-Free CLP (non-aerosol), purchased September 2015
Before collecting the IR spectra of the samples performed some qualitative analysis of each oil. Findings were as follows:
Sample #5: Translucent brown color. Somewhat viscous. Slightly bitter odor.
Sample #10: Hazy brown liquid. Slightly viscous. Somewhat oily odor.
Sample #14: Translucent amber color. Not viscous. Characteristic sharp, corrosive smell.
Sample #15: Translucent brown color. Somewhat viscous. Characteristic industrial grease
smell. Very little of the sample in vial.
Note: “Characteristic” is a very general term in chemistry. It refers to a somewhat unique (in this case) smell that you know and recognize, but can’t easily describe in other terms. For example, Hoppes #9 has a very characteristic smell that many people know and could identify, but may not easily describe to others.
Results: As stated in a previous post, the lighter line on the individual spectra is the original scan, and the darker line has been computer adjusted to a baseline. Due to software issues all spectra were printed out from the computer, and then scanned and uploaded. I would have loved to get direct images of the spectra, but the files for the spectra save as a proprietary format.
This test was interesting and unique compared to the other samples tested because they are all the same type of sample. Andrew had said that several samples would be older oils, but I didn’t know which set of oils that would be. My first clue was the similar colors, however the odors of the samples varied greatly, throwing me off a bit.
Looking at the IR spectra shows some interesting results of the oils over time. When I created the overlaid spectrum of all four samples I noticed the same peaks, but with different intensities. Typically the intensity variation will mean a lower concentration of the compounds in the sample, however if that were the case then all the peaks of a single sample would be proportionally lower. In this case, the peaks in the 3000-2800 cm-1 range are all roughly the same intensity, indicating that the concentrations of the samples are approximately the same.
The big difference between the samples is in the 1700-1200 cm-1 range, where older oils tended to have the same peaks, but with a lower intensity. Peaks in this range can indicate several bonds including C=O and C-O-C. Most of these bonds have the commonality that they involve an oxygen atoms. I believe that the lower intensity of the peaks is due to oxidation and the breakdown of these bonds. Oxygen by its nature is very reactive. Oxygen plays a key role in such things as burning and rusting, both forms of oxidation. Since the relatively stable C-H bond peaks were the same but the peaks showing oxygen decreased over time, I believe that the CLP compounds have a tendency to break down over the years. More testing should be done to examine this hypothesis, but I’m away from the labs for a few months, so we will see. It is also possible that storage conditions could change the breakdown process, or that my theory is completely wrong, so don’t go throwing out your CLP just yet. My suggestion right now would be to use your bottles of CLP within 5-10 years of buying it, and to store it in stable temperatures and out of direct sunlight.
Now we wait for Andrew to post the next results…