Locktite

[Gordon]

What locktite should be used for locking slip fit parts? I am building the Howell V-2 and it calls for locktite to hold many of the pieces at assembly. I have locktite 660 and it does not seem to be holding anything. I assembled the brass bushing in the piston for instance using 660 and let it stand over night. It was a snug fit and this morning I can twist the bushings as easily as I could yesterday. Is the locktite defective or am I using the wrong stuff? I have had the 660 for quite a while so perhaps it is too old but when I used it previously I had the same experience.

 

[chucketn]

Google found this Loctite Application Guide. Maybe this will help you.

http://www.loctite.com.au/aue/content_data/311083_7129_Application_Wall_Chart_V10.pdf

Chuck

 

[SmithDoor]

I have use Loctite that over 20 years old and still works
I use the blue loctite 603
Try Loctite 648 Retaining Compound this will close gap up to 0.006"

Dave

 

[Gordon]

Chuck: Thanks but according to that the 660 should be what I need but it is not doing anything. The 660 that I have is like a paste, actually looks like valve grinding compound. I have several other threadblockers (290 and 242) but I am sure that they are not appropriate. Should I be using a primer?

 

[SmithDoor]

Note they do make HIGH TEMPERATURE and High Strength
This will make it very hard to remove when I fine this use it need lots of heat and time to remove the part. :fan:

Dave

 

[ozzie46]

If you are trying to use it with aluminum you should use the primer.


Ron

 

[kf2qd]

For your application, the threadlocker 290 would probably work just fine. The dried out stuff you are using sounds like a good candidate for the dust bin.

You are hardly doing this for a high performance/High precision application so the Red 290 will work just fine. No-one is going to raid your shop and shut you downif it doesn't meet the exact spec, it is a model engine, you know...

 

[canadianhorsepower]

you need 480 and to separate a little bit of heat
does the trick. The 600 series are lock tight : anaerobic: and not a glue
http://www.loctite.co.uk/loctite-4087.htm?nodeid=8802626207745

or JB weld it and then again heat will separate them

 

[Gordon]

I am indeed using it on aluminum. My local supplier does not seem to stock the primer. I looked again and it seems like about half of the items I applied the 660 to seem to be holding. I am leaning toward perhaps the loctite is defective. The literature says "cream" and what I have is more like a grainy paste. It actually looks and feels like valve grinding paste.

I had never thought about using JB Weld. Has anyone used JB Weld for this purpose?

 

[canadianhorsepower]

I had never thought about using JB Weld. Has anyone used JB Weld for this purpose?

That's what I use all the time
and never failed :fan:
sorry once I was working with aluminium
taking huge cuts with a bad cutter :wall:
I generated enough heat that it came apart
I had 6 same parts to do and they never came apart
what I like it's cheap

 

[Brian Rupnow]

I use Loctite 638 on all of my aluminum parts, and never use primer. I have never had it fail me. Of course, Loctite has it's limitations. The parts being Loctited have to fit well BEFORE being Loctited.

 

[pkastagehand]

Grainy paste doesn't sound right but I've never used 660. I had some 5 minute epoxy I used recently that was like that and so I'm thinking it is too old.

Cleanliness is of course paramount. NO oil and other gunk in the joint. They sell cleaners but I've also used alcohol to effect.

Locktite is what holds the wheels on a good many scaled locomotives running around the world. (Purists still key them and use mechanical and/or press fits)

Paul

 

[BobsModels]

Hi

Just a sugestion. Call Loctite and speak with either a sales rep or a tech support. Explain exactly what you are doing and ask them for a reccomendation. I have had excellent luck with this approach. Do not tell them your opinion, just ask your question. You can then do whatever you want with the reccomendation.

Sorry to be a bit blunt but us model engineers tend to talk rather than listen, me included.

I have had excellent results by speaking directly to the manufacturers to get the correct product.

Bob

 

[Herbiev]

I use loctite 620. 3,800 psi shear strength and works in up to 15 thou slop fit

 

[toolznthings]

Learned the hard way. I use the proper primer on everything I assemble with the grade of Loctite I use. A must on non reactive materials such as aluminum.

 

[Chiptosser]

When using 660 on metals, other that those with with iron in it.
Locktite, says to use the primer, or activator.
In the locktite seminar that I attended, we were shown to heat the metals to around 150F. This works well for getting it to set in: aluminum, stainless and steels.

I use a propane torch to gently heat the area it is being used in. Let it cool before testing.
It will fill up to a .020 gap, I have been using it this way from the time introduced.
It works well, Good luck

 

[Chiptosser]

I should have said, when primer is not available, heat can be use to activate it.:wall: