Hypalon® Gluing with Alpha S49 Adhesive System

Gluing boats constructed with Hypalon® and PVC is a growing market in Ireland. The marine & watersports sector is growing year on year and we weekly receive phonecalls asking what adhesives we offer for the repair of ribs.  Industrial rubber bonding forms one of the cornerstones of our business. and through our partner Alpha Adhesives, we offer a range of adhesive solutions for the mariner. Irrespective of how careful you are when boating, tears, rips, and holes to your boat can occur. So knowing how to repair your boat, regardless of how big the job, is extremely valuable information to possess!

There is a relatively easy way to repair a hole Hypalon®  rib. First of all, cut the repair patch extending 50 mm from all sides of the damaged area. Make sure to round the corners of the patch as a square cornered patches are more likely to catch and peel than rounded ones! Trace the area of the patch on the damaged surface with a felt tip pen.

Using 180 grit sandpaper, lightly buff the bond area, this includes the damaged area on the boat and the back of the repair patch. The fabric should look like a dulled version of the normal boat surface. Be careful, don’t buff down to the point where the threads are visible. The goal here is to remove the surface glaze of the fabric, without removing excess coating!

Clean the buffed surfaces with a lint free cloth which has been dipped in T 559 thinners. The T 559 removes any contamination such as oils etc, which may otherwise inhibit the adhesion of the adhesive.

Next comes the adhesive.

After the surfaces (both damaged area on the boat and the underside of the patch) have thoroughly dried from the cleaning step, next comes the adhesive. Alpha S49 polyurethane adhesive has become the standard for this type of repair. Decant the crosslinking agent into the adhesive and stir gently for five minutes. The crosslinking agent significantly increases bond strength and chemical and heat resistance.

Next apply a very thin layer of Alpha S49 to both surfaces, using a stiff bristle brush.

After the first layer of adhesive is just tacky apply another thin second layer of adhesive to both surfaces. Test for how tacky the adhesive is with a gloved finger or by touching knuckles to the glued area. The glue should feel gummy, but should not stick to the gloved finger or knuckle. Do not use bare fingertip to test for tackiness. Fingers contain oils that will be left behind and effect the bonding quality of a repair job.

Apply a third thin layer of adhesive to both surfaces.

Once the third coat is to the just tacky stage, the two surfaces can be joined. If the adhesive dries beyond this stage, you can reactivate the adhesive by wiping the surfaces to be bonded with a lint-free cloth dampened with T 559. Join the two surfaces together when the adhesive is tacky to the touch but does not transfer when tested with a knuckle. Be careful with this step! Make sure to place the patch in the correct area. Alpha S49 adhesive is a contact adhesive, therfore, once the surfaces have contacted they cannot be moved!

Once the two surfaces are pressed together, apply pressure with a roller.  In order to remove any trapped air bubbles, start at the center of the patch and work outward. Roll every millimeter of patch in multiple directions.

Use a lint-free towel dampened with T 559 to wipe up any excess glue expelled from the patch edges while rolling

Allow the patch to cure. Curing times vary due to the different temperatures & humidity. The optimal repair environment of above 15°C and below 50% humidity. This is typical for a full cure time of 8 – 12 hours. If at all possible avoid repairs when the humidity is above 70%. When having to make a repair when you’re on a trip, you may not have a choice of weather conditions and optimal cure time. In those cases avoid over-inflating a patched tube and you may need to redo the patch when you get home! We strongly recommend this adhesive system for air holding repairs and for attaching anything that will be subjected to high load stress, such as d-rings, carry handles and footcups.

Alpha S49 Part A & B, together with T 559 are always in stock.