Ask Dr. Dave

RSS

This is a good question for two reasons: first, adhesives and sealants often have to fill large irregular gaps and expansion on curing enables them to achieve this; and second, the products usually shrink on curing.

I suspect that the concentration of your products in the water is very low, but the answer is almost certainly no!

We have some pinhole leaks in an old fire sprinkler system in a large apartment block. Is there an adhesive that will seal those leaks?

Polytetrafluoroethylene (PTFE) is low-surface-energy plastic that is very difficult to bond. PTFE exclusively comprises fluorine and carbon atoms with no polar atoms such as oxygen or nitrogen.

What does fumed silica do for adhesives and sealants compared to other thickeners like wood flour or clays, and how do you handle the huge clouds of dust from the bags?

I see references to fixture time on adhesives technical data sheets. What exactly does that mean?