When we apply wigs in house, we use either a matte spirit gum or a silicone based adhesive. These are significantly stronger bonds, and will not cause any damage to the lace or knots. Spirit gum is an alcohol based adhesive. The strongest matte spirit gum we carry is the KD151 brand. Many spirit gums are a bit shiny in various lighting scenarios, but this brand is formulated for no shine and extra adhesion. The other adhesive type we recommend is a silicone based adhesive, such as Telesis 8, Kryolan Extra Strength Medical Adhesive, or Walker Soft-Bond. If you are looking at wearing pieces for multiple weeks, there are also acrylic adhesives on the market, such as Walker Tape Ultra Hold.
All of the above options will not flake, are incredibly thin, and dry completely clear. They will allow the lace to “melt” into the skin and completely disappear.
Which ever way you decide to go on the adhesives, make sure that you are applying them directly to the scalp and not the the lace of the piece. Once your adhesive is ‘tacky’ and ready for adhesion, place the lace into the glue and tap into place. Do not push too hard, as this will cause the hairs to stick to the glue as well.
A knot sealer will not be necessary as long as the adhesive is applied and removed correctly.