Repairing Hairline Cracks in Plaster Pools

Hairline cracks may not seem like a big deal, but if not repaired properly they will continue to cause your pool to leak and cause further damage to the structure itself. Most hairline cracks can be repaired by the pool owner. Like most do-it-yourself jobs, preparation is key to success. A hairline crack must be first cleaned and exposed, filled with caulk and finally plastered.

Submersible pump
4-inch grinder saw
silicone caulking
Plaster patch
Putty knife
Trowel

Instructions

- 1
  Drain the pool with a submersible pump to expose the hairline crack. if you do not have a submersible pump, you can siphon the water from the pool instead. Larger in-ground pools may take a long time to drain with the siphon method.
- 2
  Cut the hairline crack with a 4-inch grinder saw about 1/2 inch deep and extend the crack 1 inch in length on both sides. Let the crack dry and then clean out any dust and debris from the crack. This will help the plaster and caulk bond to an even and smooth surface.
- 3
  Apply a layer of silicone caulk, filling up the crack about halfway, or 1/4 inch. Leave room for the plaster to be applied into the crack.
- 4
  Apply a liberal amount of plaster patch with the putty knife. Smooth out the surface with a trowel. Fill up the pool immediately after patching to prevent the plaster from cracking. If it will take several hours for the pool to fill up, place a damp towel on the patch to keep it moist.

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