How To Work With HEATnBOND
Geodesic Airolite Boats (http://www.gaboats.com)
This subject has been an issue for quite a while and we keep trying new ideas. Each one is the best thing since sliced bread. Well here is another:
HeatnBond is not a double stick tape, it is a dry adhesive film that is activated by heat. The shear strength is exceptional but the peel strength is only medium; however the rub rail will prevent any inadvertent peeling.
HeatnBond tape has a keeper paper on it but it has no tack so it has to be heated to tack it in place on the wood. Set your iron temp. to just below the Dacron shrinking temperature, about 225 deg.(do this with a scrap piece of Dacron).
I always advise a practice run by adhering a strip along the side of a scrap piece of wood that has been varnished; the bumpy side goes on the wood. Leave the keeper paper on and use the tip of the iron to tack it to the wood. Do a spot about every 3" and touch the iron for a couple of seconds. (NEVER EVER touch the iron directly on the glue as will make a sticky mess on the iron). If this happens you can jack the heat up a bit and rub like the devil on a piece of scrap fabric.
Now peel the keeper off and lay a short piece of Kevlar across the dry film. Take the roll of tape and lay the end across the Kevlar; heat it with the iron so that it melts into the Kevlar. You can then snip off the excess and peel off the keeper. Now you are ready to stick the Dacron in place. As you iron the Dacron the tape will melt and show through the Dacron with a waxy feel...just a few seconds on one spot as you do the entire Gunwale.
When you do this on the side of the Gunwale, leave a tail (6-8") long on the Kevlar. Now you can re-heat the glue and pull the tail to tighten the Kevlar after heat shrinking the Dacron.
When doing the Stem doubler in other words, fabric to fabric, the procedure is basically the same. The thing to remember is to not overheat, as the glue migrates towards the heat and will tend to leave a starved joint. The recommended heating time is 3-5 seconds.
In this case the finished surface will not get that waxy look, but rather a dry textured appearance. Arrange the edges so that the adhesive is just slightly smaller than the fabric to prevent getting the glue on your iron.
A patch can be pre-made by ironing the tape on a piece of Dacron, lightly glide the iron on the keeper paper for 1-2 seconds, then cut out the patch. Bend a corner and peel off the paper keeper. The glue should appear "milky". Clear, dark and shiny is a sign of overheating. If this should occur, go back and apply another layer of the glue. After ironing a patch in place, let it cool and run your finger nail along the edge. If you see or feel that it is loose, repress 1 or 2 more seconds. Like the original job, the patch should receive a final sealing coat of varnish.
|Copyright 2002 Monfort Associates.|