[miamicuse]

I have a few questions about cardboard tubing 8" diameter.


I need to make a piece about 20" long but the post around which I want to add concrete is already in place and I cannot slide it down from above due to another obstacle.


Can I cut the tube longitudinally, pry it open and place around the post, tape it back together? Any reason I should avoid doing this?


Also, how long do you keep the tube before removing it? With food form you can basically gently remove it after a day or so, with this I assume it's difficult to remove it like wood form, do you cut it up and peel it off, or do you just let it disintegrate as you mist the concrete for days and eventually it will break down enough to remove easily?

 

[ClarenceBauer]

I have cut them just like you want to do mine were larger & I used sheet metal bands & screw attached the seam back, worked great. I cut mine off with a razor knife.

 

[SeniorSitizen]

I like your tape plan. For that size 3 or 4 raps of duct tape, one at top and bottom with 1 or 2 in the middle then one top to bottom on the inside on the seam will be plenty.

 

[Colbyt]

I've never done it or what Clarence said but I suspect it can be done using really big zip ties or twisted wire, and a slow load of somewhat dry mix.

 

[Bondo]

Also, how long do you keep the tube before removing it? With food form you can basically gently remove it after a day or so, with this I assume it's difficult to remove it like wood form, do you cut it up and peel it off, or do you just let it disintegrate as you mist the concrete for days and eventually it will break down enough to remove easily?

Ayuh,..... The plain cardboard ones break-down real fast if, or when they get wet,.....

The wax coated ones take considerably longer,.....

 

[Nealtw]

When i did that, I put plywood and inside and screwed it back together.
It was about 6 ft high and fear took over. I also put 4 2x4s up the sides and built square frames to hold it all together. I am sure less would have worked.

 

[de-nagorg]

Sure can be done.

One strip of duct tape up the slit, and 3 ratchet straps around the circumference , and you are good.

Remove the straps in 2 days, leave the tube and tape another 4 days, and pull the tape, to remove the tube.



ED