Loctite

What in general is the shelf life of Loctite products? I have a twenty-year-old 50ml bottle of 601 which is about half full. Seems a shame to bin it at about forty quid a pop.

Mike

There are many discussions about this on the forum ... try the search box on the homepage

My own understanding, based on direct advice from Hemel Hempstead is:

For the anaerobic thread-lockers and retainers: If it is liquid in the bottle, it is still useable.

MichaelG.

I've used really old Loctite. Best way if you're not sure is to try it on some scrap.

My bottle of 601 was given to me about 25 years ago, and it was of unknown age then.

It still performs perfectly well every time I use it, and will probably get passed on to someone else when I am pushing up daisies. !!

Phil

I spoke to Loctite about shelf life of Loctite a few years ago, each bottle is stamped with a use by date. The shelf life is 2 years from manufacturer date to the date stamped on the bottle, they told me that after the use by date they could not say the product would work as well as the specs state. I still use various Loctites from thread lockers to bearing fit & retainers that in some bottles i have are 10years old down to 3-4 years old & all seem to work for me fine, whether they hold as strong as a in date bottle i have no idea & all i can say is every job i have used the out of date stuff hasn't come apart.

I have had no problems using old Loctite, but if your application is critical, then a test would be a good idea. Loctite products are now made in China and can be bought for much less than £40 for 50ml. For most people a much smaller bottle would last for ages.

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So ... would it be fair to deduce that whilst my 30+ year old 638 will probably last another five years or more; its new replacement might only last two ?

Clever so-and-sos these chemists [maybe]

MichaelG.
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P.S. ... No, I haven’t done comparative testing on old and new

... and like you, I am happy with the results from old.

Thanks chaps

Certainly will not throw the existing bottle away then. I think I will buy a very small 638, and out of interest run a couple of comparative tests.

It looks as if the 638 is a better/stronger product than 601 in any case so it might be horses for courses.

Mike

Would I use old Loctite in my workshop? Yes.

Would I fly on an aircraft I knew was maintained using old Loctite? No!!!

Did I religiously check the expiry dates on "consumables" when I was quality manager for an aerospace company - of course I did.

Did I then take it home a few days before it expired - well if I'd waited until it expired the company woyld have to pay to dispose of it as chemical waste

Edited By Robert Atkinson 2 on 12/11/2019 18:21:40

Go on the Loctite website for the full information on the wide range. As far as I know, they have always had a shelf life of 2 years or less.

There are lots of reasons for 'shelf life' other than product degradation. These include making sure stock is used in rotation, making sure new formulations replace old ones, helping traceability.

For 'critical applications' the product will have been tested to ensure it still works at the end of its shelf life; this doesn't mean it ceases to work after two years and a day, just that it hasn't been tested for a longer shelf life so it can't be guaranteed to still work.

I note that a similar shelf life applies to medicines but experts are at pains to make clear that in an emergency an out-of date asthma inhaler is better than nothing at all (for example).

Neil

There are obviously industries like aviation/ aerospace + others where in date Loctite would be specified to be a must, for the rest of us it probably dose not apply or matter that much. The problem also with the 2y timeline is when you buy Loctite from a suppliers they sometimes have had it sat on there shelf for some time, when i buy from a local suppliers i always look at the date stamp on the bottle. Most times there is usually around 12-18 months left on the date stamp, if i am buying online i will ask first the expiry date as some have only had a few months left on them & look elsewhere on line for longer date stamps. I figure if i am paying the same price then i might as well have longer in date Loctite even knowing i will still be using the product well beyond the use by dates.

I was told that as long as the Loctite was still fluid, it was useable.

I have used Loctite (in large bottles) WAY past the "best by" date. It was so effective that when trying to separate the two parts with a copper mallet, I eventually stopped, for fear of doing damage!

The Loctite that I use, currently is decades old, but is still pretty effective. Most of the time the shop, although well insulated, is unheated (only while I am in there, or very slightly if prolonged frost is forecast)

It works for me, but may not for you.

Howard

Most of us don't have any sort of feel for just how strong a loctite bond between adequately prepared materials is.

The actual strength is related to the area of the bond and, in lesser degree, its thickness. Most jobs folk like us use it for don't require anything like the full specified strength to function perfectly adequately. Particularly when considering the stronger types even half the specified strength is likely to be plenty for us. The bond areas involved in thread locking or fitting a shaft or bearing are quite large,

Frankly for the casual uses it's preparation quality that is likely to cause issues not the loctite. Whether factory fresh or seriously over aged.

Adhesive tapes are a good illustration of the effects of bond area on joint strength. The actual stickum isn't huge but given a decent area the joint is very strong. The weakness is in peel where you can concentrate a lot of force at the end of the joint line and effectively roll it up. If things can't be peeled up, generally the case with things we use loctite for, the joint remains intrinsically very strong.

Clive

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When I was at BAe it was our QA that applied a 'Shelf Life'

... The Loctite bottles from Hemel Hempstead were not so marked.

Well-reasoned comments [above] seconded !

MichaelG.

I have seen it quoted that Loctite did not apply a shelf life to their products until a large customer in the Aerospace industry required them as part of their quality controls...

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At which point they probably spotted an opportunity

MichaelG.

I think we can take it that Loctite is like a good wine or cheese it matures with age...

My eye Doctor uses clear nail polish with good results, and holds with less torque to disassemble. Could color coordinate if needed.