Best compound to join tube and insert 1

[duc916]

I have a tube with a 0.300" hole through the center. I need a compound that will allow a user to assemble an insert into the tube via a slip fit, but when cured will not come apart. I have tired various loctite compounds (272, sleeve retian compound), but the inserts come loose during usage. The compound will not see any shear forces due to axial loading of the tube, but will see heat (max 270F), vibration, and some twisting force (amount unkown, but not high).

Dan

 

[MadMango]

What materials are you currently using, and what is the surface finish of the ID of your tube and insertion part?

What was the failure of the Loctite material?

Ray Reynolds
"Computers in the future may weigh no more than 1.5 tons."
Popular Mechanics, forecasting the relentless march of science, 1949
Have you read faq731-376 to make the best use of Eng-Tips Forums?

 

[duc916]

The two parts are 4130 steel. The surface finish is as machined, Ra ~ 15 uin. The Loctite to this point seems to breakdown. There are still remnants of the Loctite, but the two pieces are free.

 

[MadMango]

The cause of failure could be anything, from improper cure times, too much clearance between your parts, or simply the wrong Loctite product specified. I don't think Loctite 272 is going to work in your application based on what you have provided. 272 is only a threadlocking compound, not really intented for the application you are using it in.

You might want to investigate Loctite 648, good for temperatures up to 300°F. Fills gaps up to 0.006" diameter clearance. Fixtures in 5 minutes.

Do some research on

http://www.loctite.com

if you are set on using their products.



Ray Reynolds
"Computers in the future may weigh no more than 1.5 tons."
Popular Mechanics, forecasting the relentless march of science, 1949
Have you read faq731-376 to make the best use of Eng-Tips Forums?

 

[duc916]

I am not set on using Loctite. Is there an industrial adhesive out there (two part epoxy??) that may do better than the products that Loctite produces? Thanks for the help so far.

Dan

 

[arto]

Maybe try these guys:

http://www.cotronics.com/vo/cotr/rm_threadlockers.htm

Their thread locker is good to 2100F [the only problem is you can't use a torch to soften it ;-)]

 

[unclesyd]

Here are two sites that have industrial quantities of epoxy and others that will cover most anything.

http://www.masterbond.com

http://www.dymax.com/

This is a material that you can get locally.

http://www.systemthree.com/p_metlweld.asp

 

[duc916]

Thanks for all the help. I am contacting all the vendors to get test samples of their best adhesive system.

 

[griffengm]

Duc916,
Is there a reason that this must be an epoxy? Is solder or braze an option?

Griffy

 

[duc916]

griffengm ,
I am mainly looking for a procedure that can be done in a few minutes on a bench top. The reason I have stayed away from solder and brazing is the time and equipment needed to do this. It is my understanding it would take an oven of some sort to heat the parts and braze the parts together (furnace braze?). I need a procedure that will allow the user to find the correct insert and assemble the parts relatively quick.

 

[desertfox]

Hi duc916

Have you considered a press fit instead of bonding, coefficient of linear expansion would be the same for both parts therefore no loosing with temperature. However without knowing any of the forces the components see in service it would appear to be difficult to reccomend either an adhesive or an actual imterference without testing them.


regards desertfox