How do I remove a tubular concrete form?
tim_lebsack asked:
I’d like to use a 20 inch ID sheet metal tube as a concrete form. The metal is thin, perhaps 3mm, but strong enough to handle the pour. Can I slip the form from the dry concrete? How do I remove the form without destroying both the form and the casting? Cylinder height is 24 inches.
Aluminum Metal Casting
I’d like to use a 20 inch ID sheet metal tube as a concrete form. The metal is thin, perhaps 3mm, but strong enough to handle the pour. Can I slip the form from the dry concrete? How do I remove the form without destroying both the form and the casting? Cylinder height is 24 inches.
Aluminum Metal Casting
Posted in Do It Yourself (DIY)
5 Responses to “How do I remove a tubular concrete form?”
I think the form would be stuck on the concrete.
If you split the form and lashed the halves together before you
pour the mold would be re-usable.
Also, waxed cardboard tubes are available at most masonry
material yards. After the concrete hardens the tubes are peeled off and disposed of.
You need a good concrete release agent. Check Home Centers or concrete suppliers.
A cardboard tube will handle a pour like that with no problem and you can just cut it off later. Plus it is porous so the concrete will set faster.
If the form is smooth and has no projections that would prevent it from being withdrawn from the cement when it sets. just use some motor oil to coat the inside of the form prior to pouring the concrete. This will act as a release agent. When the concrete has set, just pull the form off the casting. It may require a bit of gentle tapping to make the casting come out of the form but it will come out. Have you considered using a cardboard form from the lumber yard. They make cardboard forms specifically for concrete. I would coat the inside of the cardboard with oil but then when it was time to remove it, I would just cut it with a sharp utility knife and peel it away.
They make cylindrical cardboard forms called Sonotubes that are designed for such purposes. They are available at home centers, concrete supply houses, lumber yards, etc. After you pour the concrete, use a sharp knife or Sawzall to cut through the cardboard and remove the exposed section of form. It will be much easier than trying to remove a metal form. Hope this helps.