Will Heat Shrink Sleeves Bond to Concrete?
I was asked this question on Friday (and honestly have probably heard it once or twice a year for the last 14 years). Like most questions that I write about here (and like most questions that I am asked, to be honest), the answer is never quite as simple as it seems...so, will heat shrink sleeves bond to concrete?
The sample answer is: some will. Many of our shrink sleeve material types that utilize a mastic sealant are designed to be very, very aggressive. It is only with this aggressive mastic material that our shrink sleeves are able to bond to a wide variety of commonly applied factory pipeline coatings (including FBE, CTE, PE, TLPE, PP, etc). These aggressive mastics have been proven effective time and time again over the years.
So why is this question complicated? They either stick...or they don't! They either stay in place, or they don't! Why does everything have to be so complicated?
First we have to back up. More important than "will it stick" is "will it do what I want it to do." Believe it or not - those are dramatically different questions. Here are some of the reasons why I need to know what you want to do with it:
- Potential Problem #1 - as you probably already know (if you're working with, selling, or specifying for concrete pipe) is that concrete is porous. You don't have to look very far beyond your own driveway during a rain storm to see that. If I slap a shrink sleeve onto one section of a concrete pipe; it will do almost nothing. The first time that pipe gets wet; the area underneath the shrink sleeve will be wet as well! (not the bond line so much as the inner pipe). So in terms of actually creating a seal of some kinds - very difficult on concrete.
- Potential Problem #2 - As has been discussed here before, a bond is only as strong as its weakest link. Slap a shrink sleeve on the outside of a concrete pipe and you've created a very strong bond between the aggressive mastic of the shrink sleeve and the outermost surface of the concrete. But, how strong is that concrete? Over time, it is possible that the outermost layer of the concrete becomes brittle, gets damaged or cracked, is eroded by a water source of some kind (beyond the shrink sleeve), etc. The bond between the shrink sleeve and the concrete is only as strong as the concretes bond with itself on the outermost microns of the pipe. How strong is that bond? I'm afraid I couldn't hazard a guess - you'd need to talk to the pipe manufacturer.
That is why we need to know precisely what it is you are wanting our shrink sleeves to do. There are dozens of possible applications here, so please give me a call so we can discuss your specific project!