by Rob Cox May 24, 2013
Setting a Vinyl Liner with a Vacuum
Installing a new pool liner without wrinkles is an real accomplishment. It requires careful measurements, skillful adjustments, and a vacuum that really sucks - a lot of air.
A vac/blower, such as the Mighty Vac, shown left, or the Cyclone are used by pool pros to set liners, and if they happen to be in the snowbelt - these are also used to blow the lines for winterization.
"Setting the Liner" is what we call it. Setting the liner with a vacuum, that is, to remove the air behind the liner, and suck the liner tightly against the walls and floor of the pool.
Types of blowers used to set a liner
I mentioned the Mighty Vac and the Cyclone already. There is another industry favorite, called the Q-Vac, unique with its flattened hose that fits easily behind the liner.
You can use a Shop Vac type of wet/dry vac in most cases. It needs to be on the large side, I have used 5hp wet/dry vacs successfully. Smaller shop vacs, or those that cannot obtain a good seal to create strong suction, may not work.
Once again, these types of blower / vacs are used to remove the air behind the liner, and pull it tight up against the wall and floor of the pool, to remove the wrinkles before filling the pool with water.
They are also very useful for spotting wrinkles which aren't removed by the vacuum - those wrinkles that need some special attention, or manipulation, before filling the pool.
Getting Ready to Set the Liner
Before you install the liner, take some time to seal up any air gaps between the wall panels, or between the wall panels and the coping or track, on top of the wall. You can use silicone or duct tape to seal up any void that looks like it might pull in air, when the vac is running. Taping all of the vertical wall joints also helps with a smoother liner surface.
Install the liner into the pool, securing the bead into the track all the way around. If there are any spots where the liner is loose in the track, or pops out of the track, use liner bead to secure it, or you can use duct tape in that area.
Tape up the skimmer lids, to prevent air leakage around the lid, and also close the skimmer valve, or place the multiport valve in the closed position.
Positioning the Liner Vac
Find a location in the mid section of the pool to set up the vac. Pull a small section of liner out of the track, and insert the vacuum hose behind the liner. Try it at a depth of just 6-12", and if you need to go deeper (to create more suction), you can push the hose deeper.
Tape up the hose, as shown in the picture at the top of the page. Use lots of duct tape, on all sides, to prevent any air loss at the point where the hose goes behind the liner.
Plug your extension cord into an outlet with a large enough circuit breaker. You don't want the breaker to trip in the middle of the night, because the blower has to run until the pool is at least halfway full. A 15 or 20 amp outlet, not used by other loads, should be fine.
Setting the Liner with a Vac
When ready, turn on the vacuum. Usually within 1 minute, you should see the liner slowly tighten up against the walls and floor. After a few minutes, it should become very tight. If you have a very large pool, or a heavy gauge vinyl, or a very cold morning - you may need two vacs to set the liner, placed on opposite sides of the pool.
If the liner does not tighten up after a few minutes, check for air leaks on the vac, the hose, and anywhere around the pool. You may be able to hear the loss of suction, with a loud sucking sound, coming from one area, or you may be able to hear it or see it when you shut off the vac.
Wrinkles in your Vinyl Liner
Arggh, wrinkles! I wrote an entire post about vinyl liner wrinkles last year. If you see wrinkles in the liner when the liner is tight, make a plan to move the wrinkles to the edge of the pool, near the wall. If they are small enough, you may be able to gently smooth them out with your hands. If the liner is not properly centered in the corners, you may need to reposition the liner, so that the inside and outside corners line up.
Shut off the blower while you work out any wrinkles, and when you turn the blower on again, it may be helpful to pull and push the liner in the direction you want the wrinkle to go. Pull with your hands, or use a soft push broom to pull or push the liner in the desired direction, as the vac pulls the liner tight, as shown in the picture on the right.
Removing the Vac
Remove the vac when the water level in the pool has covered the shallow end floor by at least 6 inches. If the liner is shut off before this point, it could relax enough to allow wrinkles to appear.
Don't allow the water level to cover the hose, it can become nearly impossible to remove, and it will stretch the liner, perhaps leaving an imprint of the ribbed hose.
After removing the hose, remove the duct tape. If left on for days, it will leave a sticky residue on the vinyl, which can be removed with soap and water.
Push the liner back into the track, and spread out the excess material. Remove the other duct tape that you placed earlier, and continue filling the pool!