Tuck tape as form release

[canwesteng]

Has anyone ever heard of a contractor using tuck tape in lieu of a form release agent? I have a contractor who swears by it, I'm not sure if he's on the level though

 

[MotorCity]

Never heard of it but wouldn't you need a lot of it to cover the face of an even really small form.....not to mention the labor of putting it on the forms? He had to be joking.

 

[canwesteng]

He's covered a 1' high 10' diameter circular form with it... completely. To be fair at home I'll use tuck tape for anything.

 

[TehMightyEngineer]

We use duct tape to plug drilled holes and gaps in our forms. Small pieces will lightly adhere to the concrete and are easily removed from the concrete by hand. Pieces sticking to the concrete rather than the form happen more if the tape has any crinkles in it which the concrete grabs. Larger, smooth pieces almost always stay attached to the form (the concrete presses them into the form and they usually stay adhered).

However, using it as a form release substitute seems extremely counter-intuitive. Large pieces will embed themselves into the piece and take time to remove. Ripples and layers of tap will show on the finished piece. The tape will probably break the bond well enough but no better than any other form release agent and will likely be slightly worse. Something tells me they want a form release agent that they do not have to reapply; tape will not do this.

I see no reason not to use a form release agent for this. You can even substitute (with varying results) a bunch of alternatives that I've heard of people using; cooking oil, new (or used) motor oil, plastic sheeting, vegetable shortening, cooking spray. However, the best and easiest will always just be normal form release agent.

Professional and Structural Engineer (ME, NH, MA)
American Concrete Industries

http://www.americanconcrete.com

 

[Sawbux]

Just looked at pictures of a block-out on a culvert formed with duct tape covered foam form. Interesting texture!

I'd make sure it's on a non-visible surface or non-critical as far as aesthetics.

 

[canwesteng]

Yeah, they are planning to re use the form. We'll see how it comes out I guess. It's an industrial site so it doesn't matter how it looks and using motor oil is completely off limits. Allegedly it makes the concrete shiny, I'll add a pic if I can.