WTD: Loctite 425 threadlocker - Page 1
Forum section: electronics / general

author: flolic
author_rank: Frequent Contributor
timestamp: February 17, 2015, 10:37:52 am
content: Hi, I am looking to buy Loctite 425 threadlocker. I checked with local Henkel distributor, and apparently this product is available only in USA market.I am looking for someone willing to buy it for me and send it to Croatia (EU).I only need one bottle (20g).Tnx!

author: Fraser
author_rank: Super Contributor
timestamp: February 17, 2015, 04:49:46 pm
content: I thought 425 was instant adhesive ?Threadlock is usually 2xx range part numbers with 243 being the most common. Ebay.com usually has such thread locking fluid and many sellers ship international. Is there a specific specification that the Loctite threadlocker must meet in your application as there are other brands that claim to do the same job ?If you are after 245, it does not appear to be anything clever in terms of performance.http://tuotteet.etra.fi/en/g2317117/loctite-245-high-viscosity-threadlocking-fluidI have used the UK sourced A43 medium grip product from Bond-it, with good results.http://www.ebay.co.uk/itm/25ML-50ML-THREADLOCK-NUTLOCK-STUDLOCK-THREAD-LOCKSEALER-LOCTITE-BOND-IT-/181107512684?pt=LH_DefaultDomain_3&var=&hash=item2a2ad9556cAurora

author: flolic
author_rank: Frequent Contributor
timestamp: February 17, 2015, 06:30:03 pm
content: Yes, 425 is kind of instant adhesive.Problem with almost all of standard thread locking fluids is that they are anaerobic "glues", they only cure when applied in a very thin layer without exposure to air. Also, they don't work on plastics.I have camera repair business and need thread locker that can be applied over the bolt head, and must bond to plastic. It must be weak enough to allow easy disassembly, and strong enough to prevent loosening during use. It should be fast curing. I think 425 ideally suits my needs, but I am open to suggestionsI have 243 and it works great with metal to metal threads, but is useless with plastics. Also, it works ONLY when applied to threads.I need it for something like this:

author: Fraser
author_rank: Super Contributor
timestamp: February 17, 2015, 06:49:38 pm
content: Hi flolic,Thanks for the explanation. I know exactly what you mean now. I have worked on electronics (including all manner of cameras) for many years and have seen the red and green coloured screw head locking 'varnish' and have never identified it. From my experience there are at least two types of this screw locking material. One is very brittle and cracks away if the screw is rotated and the other stays slightly flexible a bit like old chewing gum !I would be interested in anyones knowledge of these screw HEAD locking compounds. They are not thread lock, as you say.Thanks for raising this topic. I will do some digging myself.What have I used in the past ?....... nail varnishI used to use my wife's nail varnish but now use clear nail varnish bought specifically for the task and it works well for the task.I will advise if I find out what manufacturers use on the production line. Cyanoacrylate glues or gels are not the best choice as you need to apply an activator.Aurora

author: PeterFW
author_rank: Frequent Contributor
timestamp: February 17, 2015, 06:54:45 pm
content: As far as i can see you should be able to order it from a retailer in the USA, the shipping cost is a bit high tough.My experience with threadlockers is only related to metal screws and threads.If you have not learned it the hard way, threadlocker may be permanent, even the "removeable" kind.Tiny screw heads tend to stip, even with the "low strengh" treadlockers out there.If you are not able to heat the part/screw to weaken the bond you will have a bad time.What i have been told a few times, when it comes to securing screws without disassembly of the unit, one could use nail polish and dab it on the screw head.One concern with plastic/nailpolish would be the solvent.

author: Fraser
author_rank: Super Contributor
timestamp: February 17, 2015, 07:00:54 pm
content: I have just found the stuff used on the assembly lines. As I thought, it is either red or green in colour and designed for your application. No idea where to buy it retail yet though:Looks to be called Kafuter K-200RGreen is herehttp://kafuter.en.alibaba.com/product/1590341101-218764426/Electronics_Kafuter_K_200R_Chloroprene_Rubber_Based_Neophene_Contact_Adhesive.htmlRed shown here:http://www.aliexpress.com/item/Genuine-Kraft-K-200R-red-plastic-fixed-red-plastic-plastic-screws-electronic-components-fixed-plastic/32288230578.htmlAurora

author: sdg
author_rank: Regular Contributor
timestamp: February 17, 2015, 07:09:24 pm
content: Quote from: flolic on February 17, 2015, 06:30:03 pmGloss acrylic paint (Tamiya, Gunze and the like). Or matt, if you need something weaker. Dries in minutes, fully cured in 6 hours, goes away with ethanol or propanol.

author: Excavatoree
author_rank: Frequent Contributor
timestamp: February 17, 2015, 07:23:11 pm
content: We used to use Threebond 1401B at the repair shop to replace similar substances.

author: Fraser
author_rank: Super Contributor
timestamp: February 17, 2015, 07:42:54 pm
content: Ok, Loctite do appear to make the varnish type screw head lock that I mentioned.Available through Farnell:http://uk.farnell.com/loctite/1705056/varnistop-loctite-7400-uk-version/dp/3072034This one is not flexible, it is red in colour and acts as tamper detection as well..Info here:http://www.loctite.co.uk/loctite-4087.htm?nodeid=8802630926337http://tds.henkel.com/tds5/docs/7400-EN.PDFAurora

author: Fraser
author_rank: Super Contributor
timestamp: February 17, 2015, 08:06:47 pm
content: Blimey its hard to find an obvious Google search string to locate these locking compounds !I just found this one that may be what we are looking for ? My French isn't great so I cannot read the tech descriptionComes in Red or Green so sounds like what i have seen on computer PCB's etc.http://www.itwpc.com/red-bloc-jelt_p_140.htmlhttp://www.itwpc.com/green-bloc-jelt_p_139.htmlAurora

author: zapta
author_rank: Super Contributor
timestamp: February 17, 2015, 08:16:17 pm
content: Have you considered VibraTite? It's a different kind of thread locker. You apply to the screw, let it dry, and then thread in. It's reusable so you can rescrew without having to reapply. This is what I use on my bike, car and RC models

author: Fraser
author_rank: Super Contributor
timestamp: February 18, 2015, 12:56:40 am
content: @flolic,I challenged a good friend of my father on this topic this evening. He used to work on precision instrumentation and optical assemblies. He immediately commented that differing scenarios require different screw locking technologies depending upon flex and vibration levels. The requirements of a Quadcopter may be very different to those of a metal framed video cameraThere are apparently many weird and wonderful chemistries available for locking a threaded component in place. He warned against the use of any locking fluid that generates significant vapour whilst curing if optics are involved. Such vapours inside a camera or optical block can cause clouding of lens elements or sensor windows. Cyanoacrylate has historically been a major offender on this front with high levels of 'out-gassing' during cure. It could even be used to detect and display latent fingerprints on difficult materials by a process of fuming ! More recent cyanoacrylate chemistries have reduced the level of 'out-gassing' but it is still a part of the curing process and should not be used near sensitive optics or sensors if contamination is a concern.I mentioned my use of common clear nail varnish for 'locking' the heads of screws. There is still an issue of 'out-gassing' during curing but it is apparently only of concern where plastic optics are involved.It was his advice to use a low out-gas viscous varnish and definitely not cyanoacrylate or common viscous adhesives like UHU or Bostik. I have used both in the past and understand why.... they tend to 'string' when you pull the nozzle away and can cause all manner of contamination or damage.Working with high quality optical devices does need care but even nail varnish IS acceptable if used with care in a well ventilated situation to remove any curing vapours from the equipment.A most interesting topic that you have raised and it was good to talk with someone who understood the issues this evening. I have learned something and have you to thank.Aurora

author: ivaylo
author_rank: Frequent Contributor
timestamp: February 18, 2015, 06:12:04 am
content: Quote from: flolic on February 17, 2015, 10:37:52 amSend me a PM with an address and I'll try and send you some. Prices seem to vary a lot though. I see it $25 with free shipping on Amazon and $17+$15 shipping on another place and then $33+shipping on a third (that's shipping from them to me). Have to see if this can be flown too, post office here has krazy threats about shipping chemicals, blah, blah, blah...

author: flolic
author_rank: Frequent Contributor
timestamp: February 18, 2015, 07:17:43 am
content: Thank you all for suggestions, especially AuroraAll of this make me rethink of 425 as been a ideal solution to my problem. 425 is cyanoacrylate based, and that could possibly be a problem regarding out-gassing and fogging of near by areas. That is big no-no when dealing with precision optics.I often use cyanoacrylate glues to repair broken plastic parts, but that is really not a issue if you apply glue to disassembled camera or lens part. After curing you just wipe off fogged area, but you can't do that on assembled lens...Anyway, Loctite SF 7400 should be available through my local distributor and a good alternative to what I need. I will call them today and try to get some.Quote from: ivaylo on February 18, 2015, 06:12:04 amIvaylo, thank you very much for your offer. For now I will try to get 7400 and see how that works. I really don't want to spend 100$ if there is a cheaper alternative. Product price + shipping to you + shipping to me + VAT when it arrive can easily amount that much... I'll keep you as alternative if everything other fails

author: salbayeng
author_rank: Frequent Contributor
timestamp: March 03, 2015, 07:55:51 am
content: Hi ,One needs to be extremely careful with any of the loctite nutlockers anywhere near plastic, as thay can cause stress cracking.A colleague working for a large Japanese electronics manufacturer has used "Threebond 1401B" for decades, it's a rubbery plastics-compatible threadlocker.It's sold into the european market.

author: PTR_1275
author_rank: Frequent Contributor
timestamp: March 14, 2015, 01:25:03 pm
content: We use Bloc'Lube by Electrolube here in the workshophttp://www.electrolube.com.au/products/maintenance-service-aids/blv_r/general_maintenance/It says it is more of a tamper evident seal, we use it mostly on pots, but I have used it on plastic boxes so we can tell if it has been opened, it might be suitable for what you are usingCroatian distributors are herehttp://www.electrolube.com.au/distributors/385/