[QUOTE]Chop/Abrasive saw? NO. Too good a chance to splay out the braid. And the contamination an abrasive saw creates in the hose is significant. Unless you blast it out with brake cleaner spray and air. [/QUOTE]
You need to go back and read post #10. Chop saw. YES! The proof is in the pictures and step-by-step instructions. It works, and works VERY well.
[QUOTE]Cable cutter? A better idea and certainly cleaner. The distortion of the inner tube will be straightened out when the insert end is pushed into the hose. [/QUOTE]
I have tried many types of cutters. Everything from manuals, to air, hydraulic, curved, etc. Had a problem with all of them. I would be happy to post pictures of braided hoses cut with your method. Sometimes it cause splits in the PTFE tube where it is distorted. Also tried cutting it with cores. Most cutters are designed for softer metal and we found that you cannot cut the stainless steel braids cleanly. We found that the steps in post #10 worked better. Granted, most of our braided hoses are larger then brake lines. If you have a better way, then post pictures and how you accomplished the task. I am always open to a better way or an alternate way.
Well, since I build hydraulic hose assemblies for my OEM customers on their prototype machines, I stand by the use of a specific hose cutting saw as the best preferred method to cut hose. A chop saw, or worse, abrasize saw WILL significantly contaminate a hose assembly. I've done the tests after cutting with a laser particle counter to prove it.
The issues are: a clean, square cut, and no splaying of the wire braid.
If you can adequately clean the hose after using a chop saw, then use that method. But I also know from a lot of expereince that inner hose contamination, especially the stuff we can't see, does cause problems for hydraulic circuits. Teflon tubed brake hose is VERY clean out of the box. The contamination come from cutting and handling.
A brake circuit, other than ABS systems, is very simple. So a chop saw, followed by liberal dousing/spraying with brake cleaner, followed by long blasts with compressed air should do the job.
As a chemist, I find your reference to do inorganic chemical analysis with a laser highly questionable. Lasers do play a very small role in chemical analysis. Mainly for reflective or resonance analysis. There is some limited role for laser analysis in nanotechnology. But, not for this particular application.
If you wanted to do inorganic chemical analysis for compounds that could contaminate polytetrafluoroethylene (or Teflon or FEP or PTFE for short) you would use some form of mass spectrometry. Since you brought it up, I decided to test both the teflon hoses that have been cut with a cut-off saw and cleaned with the method in post #10. And, I also tested hoses that had been splayed with the proper machine, as you have suggested. I found a very small amount negligible amount of abrasive material. It would be impossible to find zero amount. When I tested the splayed line with your method, I found MUCH higher levels of steel, chromium, nickel, molydbendum, and other chemicals. No surprise here. I am sure if I cleaned it with acetone, it would produce similar results. From this mass spec analysis, neither method is superior or inferior. I find the level from both methods negligible. You would find higher levels from the normal wear-and-tear of the moving parts.
So, does this end this discussion? No. We would have to look at the hardness of the compounds found. If you look at stainless steel and abrasive materials, you will find that SS is harder, and more likely to do damage. You would think that the abrasive material would do more damage then the SS. But, the opposite is true.
Okay, lets look at one other item. That is the chemical solubility of Teflon. As everyone knows Teflon is very resistant to chemicals and heat. That is what makes it a excellent material. But, it does have limits. I had recommended acetone for cleaning. This is because acetone is very safe from a biochemical angle. It is also rated excellent for being non-reactive to Teflon. It is also
excellent for cleaning and removing most chemical compounds. Chemist use it often to clean glassware in the lab. It leave zero residue, unlike most other compounds, like alcohol. It is highly volatile, so it will evaporate very quickly. The downside is that it is volatile and flammable, so caution must be used. I would recommend using it outside of your garage and away from flames, hot water heaters, etc.
But, Teflon does have a problem with halogenation hydrocarbons and halogenated acids. I donÔÇÖt know the chemicals used in brake cleaner, but I would suspect that both of those would be present. I would be surprised if they werenÔÇÖt present. Maybe that is why you are having a problem? Brake cleaner would be low on my list of chemical cleaners. You may have had some reactivity with the Teflon walls and the compounds in the brake cleaning fluid bind to the wall along with other contaminates. Maybe this is why you are having a problem.
Now that we are done with far more technical discussion then some of our users would like to read, letÔÇÖs use a little bit of common sense. If contamination is a concern, you can always insert a Teflon rod core in the hose and cut it however you please. This would eliminate 99% of any contamination. With a tiny bit of Yankee ingenuity you could also think of other methods of eliminating or removing contaminations of concern.
The purpose of reusable fittings is that common people can make their own hoses without expensive equipment. Tens of thousands of people have been doing it for a great number of years without a problem. I realize that you work for Parker and cater to shops that make hoses. But, the idea of the product, is that you donÔÇÖt need a professional to do the job. I have seen plenty of shops like NAPA, heavy equipment shops, hydraulic shops make them with chops saw and they never even bother to clean the lines. If I do it myself, itÔÇÖs going to be done to a better standard, and I end up with a superior product in the end. And, I think some users of the club can get the same results. It really isn't that hard to do yourself properly.
The laser tester I refer is a laser particle counter, common used to evaluate the "amount" of contminate in hydraulic systems and components. It "counts" the number of certain size particles, to compare the results against an ISO 4406-1999 standard. It does not do any chemical analysis. That is left to our chemical test labs at Parker Hannifin.
For brief exposure in teflon lined brake hoses, brake cleaner is effective and does no harm to the inner tube material. I agree, acetone is also a good cleaner.
[QUOTE]The laser tester I refer is a laser particle counter, common used to evaluate the "amount" of contminate in hydraulic systems and components. It "counts" the number of certain size particles, to compare the results against an ISO 4406-1999 standard. It does not do any chemical analysis. That is left to our chemical test labs at Parker Hannifin. [/QUOTE]
As I stated earlier, worthless for our discussion. I do understand why your company would use it, or even a shop.
[QUOTE]For brief exposure in teflon lined brake hoses, brake cleaner is effective and does no harm to the inner tube material. I agree, acetone is also a good cleaner. [/QUOTE]
I did some poking around regarding chemical composition of brake cleaner. Most didn't post the chemical makeup, but their patent filings do. CRC Brakleen used significant quantities of halogenated products, which are on Teflon's do not use list. 3M uses a primary Acetone mixture with some halogenated products. Those too would be on a do not use list. But, 3M does have a non-clorinated brake cleaner that would be acceptable for Teflon lines.