August 15, 2013

Miracle Glue

It was time to change our bimini awning.  We had it sewn in Mexico but the fellow in La Cruz had used plated steel grommets.  The perimeter was a rusty mess, the fabric was a bit sun rotted and was totally porous.  Rain would pour through it. Green mold livened up the underside.

We changed from Sunbrella to PVC coated polyester.  That's the heavy duty fabric you might see as tarps on the sides of delivery trucks.  It's quite sturdy and we used it as a sun awning on our last boat for many years.  It's totally waterproof which works well if you want to use it to catch rain.

At the Sanctuary Cove boat show there were the usual 'miracle' products available. Then there was the couple flogging this PVC/vinyl glue.  They had nice samples glued together for you to try to tear.  The PVC would go before the glue would release.  We also found it on Sailrite's website and we think they're good folks who wouldn't sell junk so be bought a tin to try.  Apparently it's also useful for hypalon dinghy semi short term repairs (like up to 1 year).



We decided to glue our awning together.  Seams and all.  We laid it out, cut the pieces on a nearby dock which was big enough.  Took about 1 hour to glue the seams joining the panels and the overlaps on the perimeter which form the method to attach awning to frame.  If we had sewn it, it would have taken many more hours and there would have been much strong language (as there always is with our big sewing projects).

Results:

It's been a few months and no issues at all.  We had one downpour where huge amounts of water were pooling in the awning and bowing the fabric downward.  No problem - and because the seams are glued not sewn, no water leaks through.

Simple lapped seam

 I was so happy with the end result that I glued together a dinghy gas can cover in about 10 minutes. 


Here's the perimeter seam with an internal PVC pipe.  We cut scallops every 6" or so for lashing string to tension to the bimini frame. Much cheaper than 100 grommets and no chafe on the string.

We're pretty impressed with it.  A few hints:  

  • it acts like contact cement.  Coat both surfaces, wait 5 minutes and join.  You get only 1 chance to position a seam right.  
  • Directions ask you to roll the seams with a hard roller. I hit it hard instead.  
  • For designing joints/seams try to keep the joint in shear
  • A simple overlap is plenty strong enough.  
  • Avoid joints where the fabric is in "peel".  In other words where the force acts first on a tiny portion of the joint peeling apart the joint.  See example below
  •  

No comments: