Columns

Ask Dr. Dave

February 1, 2012
/ Print / Reprints /
ShareMore
/ Text Size+
Adhesive and sealant troubleshooting tips from Dr. Dave Dunn.

Question: We manufacture high-value agricultural/industrial buildings using pre-cast concrete walls, and need to seal fairly large gaps between the wall sections to achieve rigidity, maximum weatherability, and water resistance. What sort of sealant would you recommend for this application?

Answer: The usual type of sealant for this application is a silicone, polyurethane or a silyl-terminated polyether sealant. However, I would also suggest that you consider a flexible two-component epoxy adhesive or sealant. Concrete does not expand or contract very much with temperature changes, and you do not really need a sealant with high flexibility.

The advantage of using an epoxy would be very high adhesion to the concrete (usually exceeding the strength of the concrete), excellent gap filling and abrasion resistance, and outstanding weatherability (although you may see some fading of color due to UV light). This type of epoxy is commonly used for sealing expansion joints in concrete floors.



Question: We need to assemble a large quantity of a consumer product and need to bond an aluminum film to 3/8-in.-thick glass. Should we use an epoxy adhesive?

Answer: A two-component epoxy would probably work well for this application but would require equipment for mixing and clamping of the components until the adhesive has fixtured. A single-component, heat-cured epoxy is another alternative, but it would require ovens for curing.

This type of application sounds ideal for a UV- or light-cured acrylic adhesive that can be cured by irradiating through the glass. Full bond strength can be achieved in a few seconds. These adhesives are expensive and require lamps for the irradiation, but the increase in productivity is tremendous.

Links

Did you enjoy this article? Click here to subscribe to Adhesives & Sealants Industry Magazine.

Recent Articles by Dave Dunn

You must login or register in order to post a comment.

Multimedia

Videos

Image Galleries

ASI April 2014 Photo Gallery

Our April 2014 issue is now available!

Podcasts

ExxonMobil Tackifier Expansion

Dwight Tozer, vice president of ExxonMobil’s Adhesion Industry business, discusses the company’s latest tackifier expansion project with Editor-in-Chief Susan Sutton.

More Podcasts

Adhesives & Sealants Industry Magazine

ASI Sept 2014 cover

2014 September

Our September issue features articles focusing on high-tech applications and raw materials, as well as a preview of the ASC Fall Convention and Expo. Check it out today!

Table Of Contents Subscribe

THE ADHESIVES STORE

handbook-sealant-tech.gif
Handbook of Sealant Technology

The Handbook of Sealant Technology provides an in-depth examination of sealants, reviewing their historical developments and fundamentals, adhesion theories and properties, and today’s wide range of applications.

More Products

ASI 2014 Buyers GuideASI's Buyers' Guide

Annual purchasing resource for equipment used in the manufacture/formulation of adhesives, sealants, pressure sensitives, tapes and labels and for application of finished adhesives. 

Clear Seas Research

With access to over one million professionals and more than 60 industry-specific publications, Clear Seas Research offers relevant insights from those who know your industry best. Let us customize a market research solution that exceeds your marketing goals.

STAY CONNECTED

facebook_40px twitter_40  youtube_40pxlinkedin_40 google+ icon ASI 30px