Epoxy post cure
Epoxy post cure
(OP)
Will the epoxy resin used in an adhesive such as JB Weld benefit from an elevated post cure as other epoxy resin systems reportedly do? and if yes will it improve the actual adhesion properties as well as the general performance?
BTW JB Weld themselves have not yet answered this question.
BTW JB Weld themselves have not yet answered this question.





RE: Epoxy post cure
At least three different test procedures were defined by ASTM, implying that the properties looked for may be different for different applications.
See:
ASTM D1002-01
Standard Test Method for Apparent Shear Strength of Single-Lap-Joint Adhesively Bonded Metal Specimens by Tension Loading (Metal-to-Metal)
ASTM D1876-01
Standard Test Method for Peel Resistance of Adhesives (T-Peel Test)
ASTM C633-01
Standard Test Method for Adhesion or Cohesion Strength of Thermal Spray Coatings
Note: this last test includes a calibration test to find the minimum properties of the adhesive, without any spray coating. This bond test is done by pulling normally to the bonded surface.
Any eventual benefit looked for in an adhesive should be tested in a way meaningful for the intended applications.
http://www.welding-advisers.com/
RE: Epoxy post cure
The Epoxy in this application is used as a filler material within the intake port of an petrol IC engine, rather than a bonding agent. As such it is subject to temperature fluctuations from 0-100 deg c, which is well within the proposed temperature range for the epoxies used (according to manufacturers information).
However the often stated objections to the use of such material is that it will not survive the repeated temperature variations and the washing action of the fuels. Naturally the failure of the material can be catastrophic.
The thoughts of a post cure was to increase the material properties cf adhesion and temperature resistance.
RE: Epoxy post cure
There are many consideration in situations as you describe and as you state failure can cause catastrophic results. One thing that is used in similar cases is to use a filled epoxy to enhance the properties of the buildup. They are several I've seen for use in your exact situation.
If you want a higher performance material a good company to talk to is Master Bond.
www.masterbond.com
RE: Epoxy post cure
In my way of thinking if the epoxy fails during the post cure to say 50deg C for 3 hours, then it would fail in use, as the cylinder head would easily surpass this temperature in operation. Similarly if it degrades then it is not really suitable for the job.
The filled epoxy I am familiar with are the loctite products and JB Weld, I will have a look at the masterbond
RE: Epoxy post cure
htt
RE: Epoxy post cure
I will contact Devcon and get specific advice.
RE: Epoxy post cure
Devcon noted that some of their products need a post cure to attain performance and all of their epoxy resins would most probably gain in performance from a post cure.
Two other well know suppliers did not return calls or emails.