Thanks for all the input. I have been researching different adhesives and room temp curing is necessary and all the adhesives I have looked at have exothermic curing reactions that begin at ordinary room temps. The bonding guide from ITW Plexus indicates that epoxies have worse fatigue life than methacrylates, and if so I think I want the latter.
After looking at data sheets for Araldite, Hysol, ITW Plexus, and ASI, it seems the best option may be the Hysol H4800:
Dexter Hysol H4800 is a highly thixotropic, two component, room temperature curing, 10:1 mix ratio methacrylate adhesive system. H4800 is formulated to provide a longer open time for manufacturers seeking between 20-25 minutes to correctly fixture parts. This adhesive forms resilient bonds and maintains its strength over a wide range of temperatures. H4800 is suitable for bonding a variety of substrates with a minimum of surface preparation.
Recommended Substrates: PVC, polycarbonate, acrylic, aluminum, epoxy coated metal, ABS, stainless steel and FRP
Non-sagging gaps filled to 1 inch Superior impact and peel strength
Little or no surface preparation Offers excellent tolerance to off-ratio mixing
Rapid room temperature cure100% reactive Excellent environmental resistance
Typical Cured Properties
Tensile Strength (psi) 3,400 3,600 ASTM D 638
Tensile Elongation (%) 25 - 35 ASTM D 638
Peel Strength (pli) 60 ASTM D 3167
Tensile Lap Shear @ 77oF 4,500 4,700 ASTM D 1002
Tensile Lap Shear @ 180oF 2,800 3,000 ASTM D 1002
Shore D Hardness 75 80
Bondline Thickness .005 1.00
Typical Uncured Properties
Part A Part B Mixed
Open Time@ 77oF - - 20 25 minutes
Fixture Time @ 180oF - - 45 55 minutes
Color Cream Yellow Light Yellow
Viscosity, cps 60,000 70,000 50,000 60,000 -
Brookfield HBT Spdl 6 @ 10 rpm Spdl 6 @ 10rpm -
Specific Gravity 1.03 .951 .02
Ponds per gallon 8.58 8.83 8.60
By Weight 9.71 - -
By Volume 10 1 -
Handling and Application
Mixing: It is highly recommended that either meter mix equipment or cartridges with static mix nozzles be used to properly ratio and dispense the adhesive. For hand mixing, combine Part A and Part B in the correct ratio and mix thoroughly. Once mixed, H4800 should achieve a uniform color. This is important! Heat buildup during and after mixing is normal. To reduce the likelihood of exothermic reaction or excessive heat buildup, mix less than 100 grams at a time. Mixing smaller amounts will minimize heat buildup.
Applying: Bonding surfaces should be clean, dry, and free of contamination. Extensive surface preparation is not required for H4800, and good bonds can be formed on most substrates after a solvent wipe. To assure maximum bond strength, surfaces must be mated within the adhesive's open time. Use enough material to completely fill the joint when parts are clamped.
Curing: Parts should remain undisturbed during the interval of time between the material's open time and
fixture time. After the fixture time is achieved the material has reached handling strength. Temperature below 55°F will slow the cure; above 85°F will accelerate cure rate.
Clean Up: It is important to clean up excess adhesive from work area and application equipment before it
hardens. Denatured alcohol and many common industrial solvents are suitable for removing uncured adhesive. Hysol H4800 is flammable. Keep containers tightly closed after use. Keep away from heat, sparks, and open flames.
Hysol adhesives should be stored in a cool, dry place when not used for a long period of time. The shelf life for H4800 is one year from date of manufacture when stored at 40oF and six months when stored at room temperature or 77oF. Exposure above room temperature will reduce shelf life.
100 gram clip packs490ml EPS cartridges 5 Gallon Pails 55 Gallon Drums
DISCLAIMER: The information supplied in this document is for guidance only and should not be construed as a warranty. All implied warranties are expressly disclaimed. Including without limitation any warranty of merchantability and fitness for use: All users of the materials are responsible for assuring that it is suitable for their needs, environment and use. All data is subject to change as Dexter deems appropriate.
Users should review the Material Safety Data Sheet (MSDS) and product label for the material to determine possible health hazards, appropriate engineering controls and precautions to be observed in using the material. Copies of the MSDS and label are available upon request