SubscriberI have a 1/4″ dia. stainless steel peg fitting into an aluminum EFI fuel rail with a clearance hole, need to glue or epoxy to hold & retain while exposed to today’s gasoline at 65 PSI?
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Shari Loushin
3M Application Engineer
Hello David, thank you for your question. Your bonding challenge encompasses several things to consider–materials, solvent resistance, joint design and potentially temperature variation in use. Considering all these factors, I would suggest you consider testing a high performing epoxy such as our DP420 Black or DP460 (I’m assuming that the temperature is not extreme on the high end since gasoline is involved).
Epoxies do not cure shrink as much as acrylics (thus they do not have as much cure stress in constrained bondlines), are more solvent resistant than acrylics, and generally provide better strength and fatigue potential on metals and better high and low temperature performance. However, these products require thorough degreasing of the bond joints; and light abrasion to remove the native oxide from the Aluminum (a weak layer in the joint) and to create a slightly roughened surface on both parts to promote bond strength.
In a constrained joint like this, I would also suggest a bondline gap of around 0.015″ (0.35-0.4mm)–thus the ID of the hole should be around 0.030″ (0.75mm) larger than the OD of the peg. This will allow for some movement of the adhesive as needed when the temperature drops.
Please reach out to us if you would like to discuss this further, or would like samples of adhesives.
