Wetsuit knee panels rarely tear through the middle. The foam stays intact, and the outer jersey peels back along the seam. Every kick works that edge wider. A flexible neoprene patch bonded to the inside, with a thin seal line on the outside, solves the problem without creating a stiff ridge against the water.
Blue70 carries Aquaseal neoprene cement in its wetsuit care range. It cures flexible, which matters at the knee more than anywhere else on the suit.
Why the knee panel separates at the edge
The knee is one of the highest-flex areas in a swim wetsuit. During flutter kick, the leg cycles from hip extension to knee flexion with every stroke. A thick, stiff patch would fight that motion. The repair has to stretch in two directions at once.
Kneeling on a rough pool deck or asphalt in transition presses grit and body weight into the knee panel. The outer jersey separates from the foam at the edge. The tear then spreads along the seam line every time you kick. On swim-specific suits, the knee area is not built as a kneeling pad. Extra rubber at the knee would catch water and restrict the kick. That is why damage usually shows up as edge separation, not a worn hole in the center.
This repair works for tears up to a couple of inches long. If the tear runs most of the way across the panel, or if the foam crumbles when you pinch it, stop and contact Blue70 support before cutting anything.
Why the inside patch works
An inside patch sits in compression when the knee flexes. An outside patch sits in tension. Peel failure starts in tension, at the leading edge. Bonding the patch inside keeps that leading edge pushed against the suit instead of pulled away from it.
Do not use super glue or hardware-store epoxy. They cure rigid and crack when the knee flexes. Iron-on fabric patches generate heat that damages closed-cell foam. Duct tape leaves residue and does not flex.
Supplies
- Aquaseal neoprene cement
- A scrap of similar neoprene from an old wetsuit
- Fine sandpaper or a nail file
- Isopropyl alcohol
- Nitrile gloves
- Wax paper
- Masking tape
- A flat weight, like a heavy book or a small board
- Sharp scissors
Work in a ventilated room. Neoprene cement gives off fumes.
Repair sequence
- Clean and dry. Rinse the suit with cool fresh water. If the knee has sunscreen, body oil, or chlorinated water residue, wipe the area with isopropyl alcohol. Let it dry completely. Adhesive will not bond to a dirty or wet surface.
- Trim and roughen. Trim loose threads and torn fabric edges with sharp scissors. Do not cut the tear larger. Lightly roughen both the inside of the tear and the patch with fine sandpaper. Wipe away dust. Roughening gives the cement more surface area to grip.
- Cut the patch. Cut the patch from similar neoprene. Leave a little margin beyond the tear on all sides. Round the corners. Square corners lift. The patch should be no thicker than the original knee panel. A thick patch rubs the back of your knee.
- Bond the patch on the inside. Turn the suit inside out. Apply a thin layer of Aquaseal to both the patch and the inside surface around the tear, then wait until the cement turns tacky, usually a few minutes. Press the patch flat from the center out to remove air bubbles. If the suit has a fuzzy inner lining, press the patch into the fibers while the cement is wet. Do not stretch the patch over the tear. Lay it flat.
- Clamp and cure. Place a piece of wax paper over the patch. Set a flat weight on top. Do not use a clamp that pinches the neoprene. Let it cure for the time printed on the tube. Do not flex the knee until the cement is fully cured. Most neoprene cements need several hours to set and at least overnight to reach full strength.
- Seal the outside. Turn the suit right side out. Tape off the area around the outer tear with masking tape. Apply a thin line of cement to the exposed seam. Smooth it with a wet finger before it skins over. Remove the tape. A thick bead becomes a stiff ridge and catches water.
Test the patch
After the outer seal cures, flex the knee slowly. The patch should move with the suit. Rinse the suit and inspect the repair. Swim easy the first time. Check the patch after the session. If an edge has lifted, clean the area and reapply a thin layer.
A small seep at the edge is acceptable in a training suit. For racing, the repair should be dry and stable. In cold water, a leaking knee repair lets cold water flush through the suit and reduces thermal protection.
When to replace instead of patch
If the patch repeatedly fails at the same spot, the foam has likely compressed. This is called compression set, and no adhesive bonds well to compressed foam. You can feel a thin, hard, flat spot. Replace the suit. If the tear runs most of the way across the panel or the foam crumbles, do not patch. Contact Blue70 support.
Prevent the next knee tear
Kneeling on hard surfaces is the most common way a knee panel starts to separate. In transition, put a small towel down before you drop to your knees. If you change on a pool deck, sit on a folded towel or a kickboard. Rinse the suit after every swim. Chlorine and salt both attack the bond between fabric and foam. Hang the suit to dry away from heat and direct sun. Do not wring it. Squeeze water out gently.
If you use a suit for swimrun, check the warranty. Blue70's Alliance SwimRun is the only suit warrantied for swimrun use. Other suits may not be covered if you kneel on rocks or run in them.
Warranty and Test Swim notes
Blue70's one-year warranty covers manufacturing and materials defects for the original owner, with repair as the remedy. It does not cover wear and tear, fingernail punctures, heel tears, zipper damage from force, heat or chlorine damage, or damage from non-swimming use. Knee panel wear from kneeling is wear and tear. If the suit is under one year old and the knee panel failed without obvious kneeling damage, contact Blue70 before cutting, keep your proof of purchase, and be ready to describe how the damage appeared.
Blue70's Test Swim policy lets you swim in a new wetsuit and still return or exchange it within 30 days if it is clean, dry, unmodified, and still has tags. Once you glue a patch, that is a modification. If you are inside that window, contact us at us@blueseventy.com before repairing.
If the suit is too far gone, use the store locator to try a replacement in person, or browse the current wetsuit collections. Happy swimming.
