NorCal Kayak Anglers

General => Craftsmen's Corner => Topic started by: Scurvy on December 20, 2017, 02:47:45 PM

Title: Scratch & scuff repair - great YT vid
Post by: Scurvy on December 20, 2017, 02:47:45 PM
I was just notified of this great technique for repairing those worn keel areas:  https://www.youtube.com/watch?v=AL0-pvp2blY (https://www.youtube.com/watch?v=AL0-pvp2blY)

Notice I didn't say that it would win any beauty contests.

The end of the vid is especially good as they discuss the various other things these experienced kayakers tried before landing at this method.  Sigh, to my dismay, they knock WestSystems' G3 Flex Epoxy -- yes, I just bought a pack of that this week to reinforce the bow & stern.  They discuss the use of milk jugs (non-colored plastic), and I suspect their results weren't so good because they were attempting the repair with just a thin putty knife.

I'll bet the milk jug might just work if one uses a more massive blade, like a painter's 5-in-1 tool or a taping knife or even a heavy duty flat scraper blade, that will hold the heat long enough to create a good, full weld.  Plus, with something heavier like milk jug, I would use strips that are only a 1/4" or 1/2" max. in width.
Title: Re: Scratch & scuff repair - great YT vid
Post by: NowhereMan on December 20, 2017, 05:43:36 PM
That's interesting. Who would ever have thought of tarp?

But, as for the G-flex, i've had that on the bottom of my Adventure/Revo-16 for a few years, and it's worked great---no pealing and it takes a beating.
Title: Re: Scratch & scuff repair - great YT vid
Post by: Scurvy on December 20, 2017, 09:14:20 PM
But, as for the G-flex, i've had that on the bottom of my Adventure/Revo-16 for a few years, and it's worked great---no pealing and it takes a beating.

Glad you mentioned the G-Flex, because from the vid, it appears they were repairing the big flat areas of the hull, which would be more subject to big pressures and flexing, which would be harder on the repair.  That said, my newly purchased G-Flex specifically describes a host of suitable substrates, but does NOT mention any plastics.  This worries me.  I'm hoping it will hold up on my keel areas, like JB-Weld seems to do.
Title: Re: Scratch & scuff repair - great YT vid
Post by: KPD on December 20, 2017, 09:23:54 PM
Thanks for posting that. Neptune’s Rangers seem like a fun bunch.
Title: Re: Scratch & scuff repair - great YT vid
Post by: NowhereMan on December 20, 2017, 09:29:15 PM
But, as for the G-flex, i've had that on the bottom of my Adventure/Revo-16 for a few years, and it's worked great---no pealing and it takes a beating.

Glad you mentioned the G-Flex, because from the vid, it appears they were repairing the big flat areas of the hull, which would be more subject to big pressures and flexing, which would be harder on the repair.  That said, my newly purchased G-Flex specifically describes a host of suitable substrates, but does NOT mention any plastics.  This worries me.  I'm hoping it will hold up on my keel areas, like JB-Weld seems to do.

This ought to give you some confidence that it'll stick to polyethylene, especially if you're willing to "flame treat":

http://epoxyworks.com/index.php/gluing-plastic-with-gflex-epoxy/

"Flame" treating just requires a quick pass with a propane torch--actually the hot gas does the trick, not the flame, per se. If you experiment with some scraps of _black_ starboard plastic, you can see how that works.

Title: Re: Scratch & scuff repair - great YT vid
Post by: krusty on December 20, 2017, 11:41:20 PM
Using vinyl tarp to repair scratches on a polyethylene kayak hull is a terrible idea. You are melting different plastics together, which will not bond well. Much better to just run a heat gun over the scratches and work the softened plastic with a putty knife.
Title: Re: Scratch & scuff repair - great YT vid
Post by: newfuturevintage on December 21, 2017, 10:29:06 AM
Thanks for posting that. Neptune’s Rangers seem like a fun bunch.

I've taken classes from/with some of them. They're nuts, but in a good way.
Title: Re: Scratch & scuff repair - great YT vid
Post by: oldfart on December 21, 2017, 10:41:25 AM
Using vinyl tarp to repair scratches on a polyethylene kayak hull is a terrible idea. You are melting different plastics together, which will not bond well. Much better to just run a heat gun over the scratches and work the softened plastic with a putty knife.

After watching the video I wondered what type of material plastic tarps are made from so I looked it up.  They are made from polyethylene laid over a nylon mesh.  I guess when it melts the poly melds with the boat and the nylon gives it extra hardness.
Title: Re: Scratch & scuff repair - great YT vid
Post by: MolonLabe916 on January 03, 2018, 11:03:19 AM
I just at looked up that g flex 655 epoxy. MAN that stuff is expensive!!!! $100 for a quart of each, resin and hardener.... sheesh. But I guess it’s better than spending $1500 on a new kayak.

Where is the cheapest place to get that stuff? Most of the places I saw online are all about the same price.
Title: Re: Scratch & scuff repair - great YT vid
Post by: newfuturevintage on January 03, 2018, 02:04:32 PM
I just at looked up that g flex 655 epoxy. MAN that stuff is expensive!!!! $100 for a quart of each, resin and hardener.... sheesh. But I guess it’s better than spending $1500 on a new kayak.

Where is the cheapest place to get that stuff? Most of the places I saw online are all about the same price.

A quart of each is an enormous amount of gFlex. I got the 4oz of each kit and have glued a fin to an inflatable, done a 4 or 5 layer buildup repair on a fiberglass SIK, used a bit here and there to fix general odds 'n' ends. I likely still have about half of each left.
Title: Re: Scratch & scuff repair - great YT vid
Post by: Tinker on January 04, 2018, 02:50:48 AM
Using vinyl tarp to repair scratches on a polyethylene kayak hull is a terrible idea. You are melting different plastics together, which will not bond well. Much better to just run a heat gun over the scratches and work the softened plastic with a putty knife.

+1  Polyethylene and High-density polyethylene are not the same.

I've been using a heat-resistant silicone hand roller to smooth scratches and it works great.  https://www.amazon.com/Silicone-Resistant-Pressure-Roofing-Installation/dp/B07588Y24G/ref=sr_1_3?ie=UTF8&qid=1515062879&sr=8-3&keywords=silicone+laminate+roller 
Title: Re: Scratch & scuff repair - great YT vid
Post by: NowhereMan on January 04, 2018, 09:33:45 PM
I just at looked up that g flex 655 epoxy. MAN that stuff is expensive!!!! $100 for a quart of each, resin and hardener.... sheesh. But I guess it’s better than spending $1500 on a new kayak.

Where is the cheapest place to get that stuff? Most of the places I saw online are all about the same price.

A quart of each is an enormous amount of gFlex. ...

+1. This is more like the quantity you need to protect the keel on your kayak:
https://www.westmarine.com/buy/west-system--g-flex-650-8-liquid-epoxy-resin-and-hardener--9223132
Title: Re: Scratch & scuff repair - great YT vid
Post by: MolonLabe916 on January 07, 2018, 10:30:16 AM
I just at looked up that g flex 655 epoxy. MAN that stuff is expensive!!!! $100 for a quart of each, resin and hardener.... sheesh. But I guess it’s better than spending $1500 on a new kayak.

Where is the cheapest place to get that stuff? Most of the places I saw online are all about the same price.

A quart of each is an enormous amount of gFlex. I got the 4oz of each kit and have glued a fin to an inflatable, done a 4 or 5 layer buildup repair on a fiberglass SIK, used a bit here and there to fix general odds 'n' ends. I likely still have about half of each left.

I was just gonna cover the whole bottom of my yak.  :smt003