What is the best locktite? and is there a certain type for certain applications?

Mike99

go to :
http://www.loctite.com
for a full description of their products. I use blue loctite for assemblies i want to disassemble without heat and red for those that wil require heat to be removed. The web site gives the correct loctite part numbers for the blue and red products. There is also a green loctite - i'm not familiar with it.

Wanna go one better?

Loctite has a free tech support line for the use of their products. Give them the EXACT description of the part to be fixtured (size and metal type AND anticipated running temp). They'll give you back the exact product rec and the correct primer to use if indicated by the metal type. This suggestion particularly applies to fixing bearings to shafts. Red 271, though it will work, is NOT the product they suggest. You'll learn a ton from them - nice people.

Ben

Red Loctite

Dr. Ben,
Could you please inform us of the proper locktite for the bearing to shaft condition?
Thanks,
Conrad

DON'T FORGET YOU HAVE TO CLEAN WATT YOU WORKING WITH!! LIKE WITH LIGHTER FUEL, OR THE LIKE. ANY OIL AND IT WILL LET GO!!!
J.C. (T.N.T.)

Conrod,

For that, you want 609 (actually, there is a small 'family' of products
for that) but 609 is all you ever find at the retail level.

Z

Here's the deal:

The strongest product (yes, you can still get stuff apart when needed with a little heat) that loctite specified for small bearing to shaft fixturing is green 603. This product is also by label more oil resistant. For application that require standing up to heat of 350 degrees or more (up to 400 I think), the product to be used is green 640. Both products are applied before assembly.

You aren't likely going to find the stuff at the local auto parts place. It IS, however, easy to get. When you have Loctite on the phone, ask for the distributor in your city. Or go straight to your local bearing supply house. Richmond, VA is not the biggest place on earth by any means, but we had no less than five places that were happy to order it for me. A 15 ml bottle of the 603 was about $15 plus shipping. I didn't get the 640 because it only came in 30 ml bottles, which was still only $30, and I sure hope no bearings in my models are running at over 350 degrees.

You need to understand that primer should be used only with inactive metals such as aluminum or SS. Normal steel like in bearings and shafts is an active metal. If you coat it up with primer, the loctite cures too soon, and the bond strength suffers. I know first hand that this does indeed occur. Loctite warned me about this specifically when I inquired about primers.

Was it worth the time and modest expense to obtain the proper product? YES!! The Fury has no less than three bearings above the clutch bell. When I pulled my model down for a motor swap, all bearings were running secure to the clutch shaft. The clutch shaft was perfect, and the bearings were just fine too.

Will other stuff work OK? Likely yes. But I can tell you that those loctite people have likely forgotten more about how to fixture assemblies and preserve component life than many of us put together. Heli parts can cost a lot. We just as well make them last as long as we can.

HTH,

Ben

WHAT TYPE OF PRIMER DO YOU USE ON ALUMINUM??
IS IT THE TWO PART PRIMER, OR IS THERE A EASIER ONE OUT THERE!!!
J.C. (T.N.T.)

Thank You Dr. Ben.

Many Thankx!

Primer info

Before I forget, the 603 came in a 10 ml bottle, not 15ml.

Anyway, the primer designations are Primer T and Primer N (I think it is N). The local NAPA store (a big one) carries a primer for anaerobic adhesives like Locite. I believe Loctite even makes it, though it carries a Permatex name. This primer is indeed acetone based, which is the description for one of the two specific loctite primers (sorry, I don't have my tech book in front of me. I can tell you that this product has worked just fine where a primer has been indicated. Remember; a light, even coat works best. Too much and you can weaken the bond.

A few other points...

The 609 that has been mentioned is a good product to use for mounting bearings to shafts. It looks like the major difference between it and 603 is that 603 is oil tolerant. Though we should all be thoroughly degreasing surfaces prior to application, there might be some situation where a perfectly clean part is not achievable. Clearly 603 would be the better choice there. If you can find 609 locally without ordering, go get it.

Loctite stresses that the primers are really only indicated when TWO inactive metals are present. I have used primer when mounting bearings in aluminum blocks (primered the ali only; ali is inactive) because I just wasn't really sure what the exact steel composite was of the bearing. I have had no problems with bond failure when I've used primer this way. I've already mentioned in the previous post how I learned firsthand about how you can goof things up by primering two active metals (plain steel on plain steel).

BTW, loctite's # is 1800 LOCTITE

Ben