Best way to insulate pipes

[jpdx]

I've insulated my PEX hot water pipes with foam pipe insulation. Now, I would like a solution for sealing the joints where two pieces of insulation come together. I tried using duct tape, but it is peeling off already. What is the recommended type of tape to use?

[BudgetSlasher]

I have always just cut the foam a little long/added a small piece to keep the whole thing under slight compression and sealed up.

If you really want to seal them, I suppose you could try 3M Foam Fast 74 spray adhesives on the butt ends. While I haven't used it I have used various other 3M spray adhesives with good results (when used on their intended substate).

There is also an application specific glue at home depot, but the reviews aren't too good, but that seems to be dealing with old stock mostly. (https://www.homedepot.com/p/Armacell-Low-VOC-520-Pipe-Insulation-Adhesive-AAD520002B/202521370)

[lthenderson]

They make special tape for foam pipe insulation and you usually find it right next to the display of pipe insulation. Mine is around six years old and is still adhered well to the pipe insulation.

[Jon Bon]

What's the return on this?

Pex is already a decent insulator (compared to copper) and putting the foam on them makes them even better. I would not bother going crazy on insulating the pipes, you are just not going to get that much of a return in dollars or degrees.

[jpdx]

Jon Bon, fair point. I'm not expecting a measurable return in dollars or degrees, I just want to know I've done everything I can to maximize the efficiency of the system.

My main area of concern is the corrugated copper pipes that connect directly to the water heater -- those are like a heat sink and are difficult to insulate with foam sleeves unless you also tape them pretty well. I also want to seal the foam joints wherever there are brass fittings since those are also small heat sinks.

I'm thinking Gorilla tape might be the way to go. It's cheap, strong, and good to have around the house anyway. I will also look into the tape suggested by lthenderson -- thank you.

[AccidentalMiser]

Jon Bon, fair point. I'm not expecting a measurable return in dollars or degrees, I just want to know I've done everything I can to maximize the efficiency of the system.

My main area of concern is the corrugated copper pipes that connect directly to the water heater -- those are like a heat sink and are difficult to insulate with foam sleeves unless you also tape them pretty well. I also want to seal the foam joints wherever there are brass fittings since those are also small heat sinks.

I'm thinking Gorilla tape might be the way to go. It's cheap, strong, and good to have around the house anyway. I will also look into the tape suggested by lthenderson -- thank you.

Two things.  They make pipe insulation that has adhesive already on it with little strips of peel-off plastic that you peel and stick the sides of the seam together.  I use this type almost exclusively.  Otherwise, I just get a bag of Harbor Freight zip ties for a couple of bucks and zip tie them every six inches or so.