Hi this is my first post so please be nice! Have been shooting air guns for over 50 years, a research and development scientist for about 40 years and yes you can breakdown krytox in a air gun but there is no doubt in my mind that its breakdown to TOXIC by products is related to compression temperatures. We all know that a drop of oil in the compression cylinder will cause dieselling (and this indicates very high temperatures), and usually the more powerful the air gun then the greater diesel effect. Here in Australia we do not have a 12 fpe limit and any air gun must have a licence (and I am impressed what you folks can do with sub 12 fpe air guns) but now shrouded air guns are illegal (unless it was a shrouded gun licensed up to a year or so ago) so thus my interest in spring guns of high power and quietness (compared to most pcps of commensurate power). I have spent over a year working over a UK built Webley Patriot in .25 cal (yes I know it's big, heavy and hard to cock (I'm 68 years old with arthritis) but it's simple to work on (5 minute tear down) but it "tears apart" Krytox especially noticeable if shot inside or on a wind free verandah. You leave quick! It is much worse than Chlorine gas and that is bad enough for your lungs. Using kryox and Moly with .25 cal H&N FTT I observed and average velocity of 853 f/s; switching to all Moly lube 858 f/s (and smoke or fumes unlike krytox). I'll stick to moly especially since my mv's are now above 900 f/s with this pellet. Yes the velocity data is correct as both my Oehler and CED Mk2 agree and yes I can hit the broadside of a barn. So, is kytox for you? If you cannot notice even the slightest smell (inside/low airflow) then stick with it.
The Anti's will be all over this thread, banging on about a krytox smoking ban and, how its second hand fumes are dangerous... next theyll want us to stop shooting our rifle in the car whilst driving if we have toddlers in the backseat - I mean, come on.. how many liberties do these titboxes want taken away!?
If I you want to deisel, do it in the privacy of your own home, thats what theyll say.
Donald
Luckily the 12fpe limit reduces the risk of that occurring to almost zero .25 calibre at 850fps+ is way over our limit, it's 50 fpe! i.e. nowhere near our low power limit which doesn't produce anywhere enough pressure to break it down.
Do you know what the required pressure to break down Krytox is? A more useful set of data that shows temperatures and pressures required would be a less "scare mongering" way to provide information that's relavent to the UK 12fpe limit rather than what happens in a 50fpe "monster" cannon.
Cheers
John
Last edited by Snooper601; 21-12-2014 at 12:17 AM.
Snooper601 Suspect a simple fault, or a simple engineer He who dies with the most toys wins!
QHAC Official lubricant development engineer.
But not at 12fpe! He's saying what happens in a 50fpe monster, 4 times the power!
.25 takes the same spring power as a .177 at 12fpe, so how much do you think the pressure/temp would need to be raised to get an extra 38fpe?
We need real data from Dupont, not irrelevant scare stories about cannons.
Cheers
John
Snooper601 Suspect a simple fault, or a simple engineer He who dies with the most toys wins!
QHAC Official lubricant development engineer.
Don't shoot the messenger John.
There is some life outside the UK you know? You're on the WWW, that means that even people outside your beautiful country can (and do) read this forum. And those people do not always have the 12fpe restriction.
You want info from Dupont?
No problem. Look for relevant information at the MSDS-file: http://www.msdshazcom.com/DOD-HMIS/0...sical/Chemical
There you can read that krytox disintegrates at temps above 260C (and yes, even a 12fpe compression will be high above that temp, read the Caldwells).
The gasses may causeA FLU-LIKE CONDITION WHICH OCCURS SEVERAL HOURS AFTER EXPOS & SUBSIDES WITHIN 24 HRS EVEN IN ABSENCE OF TREATMENT.
POLYMER FUME FEVER DOES NOT CAUSE PERMANENT INJURY
So, Pjinoz is not talking complete nonsense.
But the gasses are very easy to prevent: Don't use to much krytox "because it doesn't burn anyway...".
Just lubricate like you would when you were using the mineral lubrication and you did not want combustion.
Problem solved.
ATB from outside the UK,
Leo.
Got to love how people just go with whats always been the norm....lubes that burn etc and they wonder why seals burn away and power rises etc...
Finish line in a UK springer will not break down, in a .25 magnum in the US it might although I doubt it. You stand more chance of Halfords 2% moly breaking down than Finish line breaking down...cheap grease is cheap for a reason
The one thing you MUST do when you run Finish line, Ultimox, or Krytox is wash the gun out...squeaky clean, and do not allow lubes to cross contaminate...so just use 1 lube for everything
dead simple!
Please correct me if I got you wrong "lubes that burn etc" do you mean that this is the reason magnum guns achieve their power? If you note the data that I posted comparing velocity of Krytox/moly versus hydrocarbon/moly the difference is only 6 fps in favour of the hydrocarbon/moly over the Krytox/moly and and I try to test under IDENTICAL conditions such as temp. and atmos. pressure with identical batches of pellets. Of course I never intentionally lube in front of the piston seal and NO I do not see any piston seal burning (although I have only put about 1000 pellets through the gun using this particular seal). Don't really see what all the fuss is about; these are my observations others will have their observations. It's all about the acquisition of knowledge. For example, when I acquired this rifle second hand it was over sprung with a Macarri monolith mainspring and was producing 28.6 fpe now it's 36.5 fpe. Why did I do it? For fun, that's what shooting is all about! Lot's of disappointment along the way but offset by success resulting in over 40 pages of data. So, no criticism intended or meant for anybody and I really enjoy reading about what you guys are doing, it's all useful stuff!
cheers
I see it this way...old school lubes create an increase in temperature within the compression cylinder on the compression cycle...so you will see temperatures of 700c+ for a split second or so.
I 100% lubed a 95 to experiment with Ultimox, its a .22, i shot 300 pellets one afternoon with batches of 50 or so being loaded and shot very quickly, to try to raise the temperature of the gun. I have done this with many lubes and seen increases of combustion once the gun gets hot...with the 95 on Ultimox this did not happen.
I then proceeded to shoot around 2.5k pellets before I stripped the gun to look at the seal and inspect for burning etc...it came out as clean and undamaged as the day I put it in.
So...i hear what you guys are telling me that ptfe breaks down etc etc, but the proof was in the eating for me and i found the run ran cooler, was quieter, more consistent, felt quicker, had no combustion and overall just felt right. its still lubed with Ultimox and still shooting as well as it was when i tested Ultimox all those months ago.
So...stop quoting what you read and get testing...it is that simple, make your own mind up based on facts you prove to yourself.
Finish Line is just a cheaper version of Ultimox, its very close on the same composition, its way cheaper however. Now snooper decided to have a try of it after i suggested it and then mixed in some moly powder which he says makes it even better...good for him I may give it a go. I have also started using STP and moly powder mixed 4:1...this is seriously slick.
If anyone wants to copy my recipe you can send me a bottle or 2 to keep me in lube as a thank you
last, I must have 50 tubs of Walther spring and seal grease to hand now, keep an eye on the for sale section, i will be doing bundles of 3 of each nice and cheap when i have a clear out over xmas...the spring grease is very high in moly content and is actually good for seals also ...however it burns like most standard lubes do...choice is yours
John, no scaremongering implied but the temperature limit is 400C or thereabouts. Do not try heating your PTFE coated fry pan to these temperatures or your lungs will be in very poor shape. However, breakdown will be a function of temperature and time so higher temperatures equal shorter time and if you gun diesels with hydrocarbon oil then its over 400C (otherwise your diesel engine would not run). But what about 12 fpe guns? Temperature will likely be lower and time possibly the same. My choice is hydrocarbon grease plus Moly and if you are happy with krytox then that's fine. BTW I wish I had a 50 fpe monster cannon but sadly at the velocity above its only about 32 fpe. Sigh.
cheers
It's the ptfe one, I bought a large bucket.
I use it on the piston and seal but use ordinary hd moly on the spring and guide and sometimes red rubber grease on the spring to sap a little power if required.
The ptfe mix is great for the piston as it doesn't diesel if you get a little in front of the seal.
Cheers
John
Snooper601 Suspect a simple fault, or a simple engineer He who dies with the most toys wins!
QHAC Official lubricant development engineer.