How to Use Contact Adhesive: Formica, Laminate, Leather and Rubber
To use contact adhesive, coat both surfaces thinly, let them dry until the glue is tacky but no longer wet, then bring them together once, in the right position, and press hard from the centre outwards. On Henkel Conta Contact Adhesive Universal the pack gives an open time of 10 to 15 minutes. You get one attempt: the pack warns that moving the pieces after contact costs you bond strength.
What contact adhesive is for
Contact adhesive bonds two thin, flat faces across their whole area. It is the glue for laminate and formica onto board, veneer, plywood, MDF and blockboard, leather onto seat frames, rubber and cork, and shoe repair. The Conta tube carton lists wood (mbao) and leather (ngozi) among its substrates. It grabs instantly on contact, so there is no clamping, but also no sliding a piece into place.
The Conta pack gives an open time of 10 to 15 minutes, a service range of −5 °C to +80 °C and a flexible, heat-resistant bond. Henkel publishes no coverage figure, cure time or technical data sheet for Conta that we can find, so this guide quotes none.
What it will not stick
The pack states that Conta is not suitable for polyethylene, polypropylene, Teflon, flexible PVC and polystyrene. Flexible PVC rules out rexine and other vinyl-coated upholstery cloth, and polystyrene rules out foam insulation, polystyrene ceiling tiles and most foam trim. If you are not sure what a plastic is, test an offcut first.
Laminating formica or veneer onto board: step by step
The steps below are general workshop practice for contact adhesives, not a Henkel instruction, apart from the open time and the alignment warning, which are on the Conta pack.
1. Prepare and dry-fit
Cut the laminate slightly oversize so you can trim it flush later. The board must be flat, dry and free of dust, oil and old polish. Dry-fit the sheet to check it covers everything. Work somewhere warm and dry: a cold or damp board is a common reason bonds fail.
2. Coat both faces
Spread a thin, even coat over the whole of the board and the whole back of the laminate with a notched spreader or a brush, right to the edges. Contact adhesive only bonds where glue meets glue, so a bare patch is a hollow spot. Porous MDF edges often need a second coat.
3. Wait until it is touch-dry
This is where most jobs go wrong. Join the faces too soon and trapped solvent leaves a weak bond that lifts at the edges. The usual check is the knuckle test: press a clean knuckle lightly on the glue; if it is tacky but nothing transfers, it is ready. Then bond within the 10 to 15 minute open time. Leave it too long and the faces stop grabbing.
4. Line up on spacer sticks
Lay clean sticks or dowels across the board, rest the coated laminate on them and line it up. From one end, pull the sticks out one at a time, pressing the sheet down as you go.
5. Roll or hammer from the centre out
Press the whole surface firmly with a J-roller, or a hammer on a padded block (see types of hammers), from the centre to the edges to push out trapped air. Trim the edges flush with a router or file.
Leather, rubber and shoe repair
As general practice, the method is the same: clean and roughen both surfaces, coat both, wait until touch-dry, then press once and hammer firmly. Clean old glue off shoe soles first. A leather-look seat cover may be rexine, which the pack excludes.
Why contact adhesive bonds fail
| Failure | Likely cause |
|---|---|
| Edges lifting after a few days | Bonded while still wet, or edges not coated |
| Hollow or bubbled patches | Bare spots in the coat, or not rolled from the centre out |
| No grab at all | Open time missed, or the material is on the exclusion list |
| Laminate peels off cleanly | Dusty, oily or cold board |
| Weak bond after repositioning | Pieces moved after contact, which the pack warns against |
Ventilation and fire risk
The Conta pack states it is toluene free with n-hexane under 2%, but it is still a solvent adhesive, and the carton carries an orange FLAMMABLE pictogram. As general safety guidance: open windows and doors, keep away from cookers, welding, cigarettes and sparks, keep it off skin and eyes, and close the tin between coats. Read the warning panel on the pack before first use.
Which Conta size for which job
Conta is sold by the full carton. The per-unit figure is simply the carton price divided by the number of packs. The “suits” column is general guidance, not a coverage figure.
| Carton | Price | Per pack | Suits |
|---|---|---|---|
| 36 × 50 ml tubes | KSh 4,680 | KSh 130 | Shoe repair, small leather and rubber fixes, retail counters |
| 24 × 100 ml tubes | KSh 6,240 | KSh 260 | Household repairs, edging strips |
| 24 × 250 g tins | KSh 9,840 | KSh 410 | Small laminate patches, upholstery |
| 24 × 500 g tins | KSh 16,320 | KSh 680 | Worktops, shelving, single cabinets |
| 12 × 1 litre tins | KSh 16,680 | KSh 1,390 | Fundis laminating kitchens and furniture |
| 4 × 4 litre tins | KSh 18,720 | KSh 4,680 | Furniture and shopfitting workshops |
When another glue is better
Veneer in a press: PVA wood glue
If you have a press or enough clamps, a white wood glue gives you time to position veneer, which contact adhesive does not. The Pattex Wood Glue Economy (Mitiplast) pack carries Henkel's instructions for cold or hot pressing; cartons start at KSh 2,640 for 24 × 250 g and KSh 4,320 for 12 × 1 kg. Ponal Professional, Henkel's trade grade, runs from KSh 6,000 for 24 × 250 g to KSh 19,730 for a 30 kg pail. Henkel publishes no EN 204 water-resistance class for either, so as a general precaution treat them as glues for dry indoor work unless you have the data sheet. Our wood glue guide compares them.
Panels onto masonry or metal: PL 150
For fixing a panel or batten onto blockwork, metal or rigid PVC, Pattex PL 150 fits better. Henkel publishes it for absorbent and non-absorbent surfaces, with gap filling up to 10 mm and a minimum 48-hour full cure; where both faces are non-absorbent, Henkel's method is to spread both sides and let it flash off before joining. A carton of 12 × 380 ml is KSh 11,280. See which construction adhesive to use and adhesive vs silicone vs foam.
Where to buy
Conta is in our contact, PVC and specialist adhesives collection, and the wider range is under adhesives and wood glue. Collect free from our Nairobi trade counter at Royal Business Park, opposite Complast, Old Mombasa Road, Monday to Saturday, 8:00 to 17:30, or order for countrywide delivery at a flat KSh 350, free on orders over KSh 15,000. For help choosing a size, message us on WhatsApp. Workshops and hardware shops buying regularly can request a trade quote on our trade page.
Common questions
How long should contact glue dry before joining?
Until it is tacky but no longer transfers to a knuckle, and then within the open time. For Conta the pack gives 10 to 15 minutes. Henkel publishes no figure for full cure.
Can I reposition laminate after it touches?
No. The Conta pack warns that moving the pieces after contact reduces the bond strength. That is why the spacer-stick method matters.
Will contact adhesive stick rexine or foam?
Not Conta. The pack excludes flexible PVC, which covers rexine, and polystyrene.
What is the contact adhesive price in Kenya?
Our Conta cartons run from KSh 4,680 for 36 × 50 ml tubes to KSh 18,720 for 4 × 4 litre tins.