Epoxy bonding metal to metal

[IngeniumJD]

I have a contractor client who is presently installing helical piers in residential foundations. At the top of the helical piers is a metal cap plate that typically slips over the shaft of the helical pier and is through bolted. The helical piers are typically installed to a particular depth, and this contractor has been cutting off the excess shaft and welding the cap plate and sleeve to the shaft. In an effort for cost-effectiveness and time saving, the contractor is wanting to use some kind of epoxy bond to make this connection. This helical pier (and connected cap plate) will be embedded in the concrete footing. He is offering to have a field test done, but knowing this contractor he will probably attempt to "field test" by applying tension to the cap with his backhoe. Any thoughts on how I should consult?

 

[RARWOOD]

I don't think his idea will work. I doubt that he would be able develop the bond strength required unless you require a real low tensial strength. Even if this would work in the shop I would have concerns about doing it in the field.

Several problems exist when using glues in the field. One problem is being able to develop the clamping force required to get a good glue bond. Consistent quality control is hard to maintain. Weather can have a big influence on the results.