Here's a Video on sealing seams with HH66

[hdflame]

I just saw a video that Sailrite has on YouTube where they use HH66 to seal a seam and make it waterproof.  They're doing it on a vinyl coated truck tarp type material, but I wonder wouldn't it work on canvas or sunbrella type material too??

Watch the video and tll me what you think.  I know several of you have had problems in the past with sunbrella boat covers leaking.  Maybe this is the answer?

Hope it helps someone. ;D

http://www.youtube.com/watch?v=4hdQ-_fvyEY

[DBR1957]

HH-66 is actually a vinyl adhesive that melts the vinyl. The vinyl needs to be fairly new also.
A marina I know just tried to patch some tarps over covered slips and they didn't hold because
the material was to old. Brushing HH-66 on Sunbrella or canvas will show up pretty and make
a nice top look terrible.

For sealing seams in Sunbrella, dip a foam paintbrush in 303 Fabric Guard and apply liberally.
Works great! Plus, it coats the thread with UV protection.

[hdflame]

HH-66 is actually a vinyl adhesive that melts the vinyl. The vinyl needs to be fairly new also.
A marina I know just tried to patch some tarps over covered slips and they didn't hold because
the material was to old. Brushing HH-66 on Sunbrella or canvas will show up pretty and make
a nice top look terrible.

For sealing seams in Sunbrella, dip a foam paintbrush in 303 Fabric Guard and apply liberally.
Works great! Plus, it coats the thread with UV protection.

That's good to know.  I know it's been discussed on here in the past about having problems with seams leaking. 

I don't do marine tops, but thought the link would help.  Good to know that the 303 will work better.

[fragged8]

over here on boat tops made from PVC they sew them first then instead of top stitching
they weld the seams with an ultrasonic welder.

[hdflame]

over here on boat tops made from PVC they sew them first then instead of top stitching
they weld the seams with an ultrasonic welder.

That's cool.  Any pictures of what the welder looks like?  I bet it ain't cheap!

[RandyOnR3]

  I learned a trick from an old fart who had been in the business for a number of years.. and that was to use wax on the seam.. you can buy wax in any store for canning..  carv the bar of wax down to a point and then rub it into the seams, cant see it and it takes a really hot temp to melt it out.. 
  the down side is, you dont use it on light colored tops as the wax will collect dirt and the seam will show as a black line, but on darker colors, it works great.....

[fragged8]

no sorry hd , not got any pics. but i want to buy one so if i find one
i'll post it up.

Rich

[Darren Henry]

I swear by HH66. In my former life; Master took on the repair contract for Red wing shoes in Winnipeg.The had one style of sole that we could not get to stick worth beans so we tried every vinyl adhesive and technique available. The winner was HH66 applied and allowed to dry min. one hour, second coated and left another hour, then re-activated with heat and pressed together. I once built a 1500 pound lift bag for my friend's dive company (12' sausage of Vintex/Herculite/what ever your supplier calls it) with dump valves and web straps and seams ---- sewn in. Seams were treated with HH 66 like the tip that is going to follow and then top coated like the video. I inflated it to volley ball full Friday night and it was a blonde hair softer Monday morning. Fully inflated at 90 feet [3 atmospheres of pressure] Dave could see no bubbles escaping.

they didn't hold because
the material was to old

Old vinyl will need to be cleaned well with methyl hydrate,acetone (sparingly), or mineral spirits or lightly sanded.

For sunbrella,Gladiator (all weather), etc what we do is run a bead of 503 latex glue in the salvage after we sew the two panels together and run it out with our finger, then top stitch.

Iosso also make a very good seam sealant for "canvas" that I get through J. Ennis fabrics. It comes in a "bingo dauber" and dries perfectly clear.