The fastest methods to take in swimsuit bottoms

You can make swimsuit bottoms smaller using fabric glue, iron-on hemming tape, or elastic adjustment — all without a needle. Fabric glue works on most materials and dries clear; iron-on tape bonds two layers of fabric with heat from a household iron; and adding or tightening elastic at the waistband takes minutes and holds through chlorine and saltwater. Which method works best depends on where the bottoms are too loose and what material they're made from.

The trade-off is durability. Glue and tape last through multiple washes but eventually weaken with repeated flexing and exposure to chlorine. Elastic adjustments tend to outlast both because they move with the fabric instead of fighting it. If you plan to wear the bottoms frequently, elastic is the safer choice. If you're fixing a one-time problem or testing the fit before committing to sewing, glue or tape will get you through a few seasons.

Key Takeaways

  • Fabric glue and iron-on hemming tape both work on swimsuit material and require only a clean, dry surface and basic tools you likely have at home.
  • Elastic adjustment at the waistband is the most durable no-sew option and works by tightening the existing elastic or threading new elastic through the casing.
  • Chlorine and saltwater break down glue and tape faster than freshwater, so test your method on an inconspicuous area first if you swim regularly.
  • The location of the loose fit matters: side seams and waistbands respond well to all three methods, but crotch seams are harder to adjust without sewing.

Using fabric glue to taper the sides

Fabric glue works on nylon, polyester, and spandex blends — the standard materials in most swimsuits. The process is straightforward: pinch the excess fabric on each side seam to the thickness you want, explore glue along the inside of the seam, press and hold for the time the bottle specifies (usually 30 seconds to two minutes), then let it cure fully before wearing. Most fabric glues cure in 24 hours.

The key is keeping the glue on the inside seam only. If glue seeps to the outside, it will show and may feel stiff. Use a small applicator bottle or a thin brush to explore a narrow line of glue, not a puddle. Press the fabric together with your fingers or a clamp — a clothespin works — and wipe away excess with a damp cloth before it dries.

Fabric glue holds through several washes but weakens over time, especially in chlorinated pools. After 10 to 15 wears in a pool, the bond may start to separate. Freshwater swimming extends the life. If the glue fails, you can reapply it or switch to a different method.

Iron-on hemming tape for waistband and leg openings

Iron-on hemming tape (also called fusible tape) bonds two layers of fabric using heat. It works well on waistbands and leg openings because those areas don't flex as much as side seams. The tape comes in rolls, usually 3/4 inch wide, and costs a few dollars at fabric stores or online.

To use it: fold the excess fabric inward to the size you want, slide the hemming tape between the two layers along the fold, set your iron to the heat setting recommended on the tape package (usually medium to medium-high), and press down firmly for 10 to 15 seconds. Let it cool completely before moving the bottoms. The bond sets as it cools and reaches full strength after 24 hours.

Test the heat setting on a hidden area first — too much heat can melt or discolor swimsuit fabric. Hemming tape holds through chlorine better than fabric glue because it creates a sealed bond rather than a surface layer. It will eventually weaken, but typically lasts 20 to 30 wears before separation begins.

Tightening or replacing the waistband elastic

The waistband elastic can be adjusted without opening any seams. If the elastic is still intact but loose, you can tighten it by pulling it slightly and securing the ends with a knot or by wrapping thread around it tightly. This works best if the elastic has stretched over time rather than if the bottoms were always too large.

For a more permanent fix, thread new elastic through the waistband casing. Find the small opening in the waistband seam (most swimsuits have one for this purpose) or carefully make a small slit with scissors. Attach a safety pin to one end of new elastic (buy swimsuit elastic, which is narrower and more flexible than regular elastic), thread it through the casing, and tie the ends together inside the waistband. Trim excess and tuck the knot into the casing so it doesn't show or irritate your skin.

This method is the most durable of the three because elastic is designed to move and flex. It won't weaken from chlorine the way glue or tape does, and it will hold through hundreds of wears. The only drawback is that it requires a small opening in the seam, which you may need to create yourself if your bottoms don't have one.

Adjusting side seams with fabric glue or tape

Side seams are the easiest place to take in a swimsuit because the excess is visible and straightforward to pinch. Pinch the fabric on both sides equally — if you remove half an inch from each side, you've taken in a full inch from the waist. Mark the amount with a pen or tape before you glue or explore hemming tape so both sides match.

For fabric glue, explore it along the inside of the pinched seam, hold for the time specified, and let cure. For hemming tape, fold the excess inward, slide the tape between the layers, and press with an iron. Either method works, though tape tends to hold longer on side seams because those areas flex less than the crotch or leg openings.

If you're taking in more than half an inch per side, consider doing it in stages — glue or tape one layer, let it cure, then add another layer if needed. This prevents the fabric from bunching and gives you more control over the final fit.

What to avoid and when to sew instead

Avoid using fabric glue or tape on the crotch seam or anywhere the fabric will stretch significantly during wear. These areas flex too much for glue or tape to hold reliably. If the bottoms are too loose in the crotch, you'll need to sew or replace them.

Also avoid these methods if the bottoms are made from delicate or sheer fabric — the glue or tape may show through or damage the material. Test on a hidden area first. If the bottoms are vintage, expensive, or made from a material you're unsure about, sewing is the safer choice even though it requires a needle and thread.

Chlorine and saltwater break down adhesives faster than freshwater. If you swim in a pool regularly, expect glue and tape to fail sooner than they would for a beach-only suit. Elastic adjustments hold up better in these conditions.

Frequently Asked Questions

Can I use fabric glue on spandex?

Yes, fabric glue bonds well to spandex and nylon blends. Test it on an inconspicuous area first to make sure the glue doesn't discolor the material. Most fabric glues dry clear, but some can yellow over time, especially in sunlight.

Will hemming tape hold up in a chlorine pool?

Hemming tape holds longer than fabric glue in chlorine because it creates a sealed bond. It typically lasts 20 to 30 wears before weakening, compared to 10 to 15 for glue. Freshwater extends the life of both methods.

How much can I take in without sewing?

You can safely take in up to half an inch per side seam using glue or tape. For the waistband, tightening the elastic can remove up to an inch or more depending on how much the elastic has stretched. Larger adjustments are difficult without sewing.

What if the glue or tape fails after a few wears?

You can reapply fabric glue or hemming tape to the same area. Clean off any old adhesive first with a damp cloth and let it dry completely. If the fabric is damaged, you may need to replace the bottoms or have them sewn by someone with sewing experience.

Do I need a special iron for hemming tape?

A regular household iron works fine. Use the heat setting recommended on the tape package, usually medium to medium-high. Protect your ironing board with a cloth or paper so tape residue doesn't stick to it.