Using West Systems G-Flex 650 ‘flexible epoxy’ on leaks

Saw this article today, the 'heat & apply' technique looks pretty good! The technique should also work for those with Glu-Vit on hand ... I would just use less heat, as Glu-Vit is already much thinner as a mix than G-Flex is.

Dale, I have not used Gluvit in a very, very long time
and even then, it was on a wooden boat . . . .
so I don't recall the flex properties of it.
I have recently acquired an old Lone Star that has
some really bad seams that are filled with all kinds of junk
that has to be removed first........
Then, I would like to caulk the open wounds with
something flexible prior to replacing the rivets.

So, with the G-Flex in mind, would you fill the seams first
then replace the rivets ? or, vice-a-versa ?
My thought was to mix some white/black 5200 to make some
gray sealer and go that route, but, am always open to new products.
The G-Flex seems like it will flow into the seams better than smooshing
the 5200 in with the fingers.
The inside of the boat will eventually be painted the original factory color.
Won't be starting that project until the middle of July at my new house.

and yes, those are sheet metal screws from the inside of the hull
to hold the seam closed - - - - -

I would re-rivet then apply sealer.

lckstckn2smknbrls said:

I would re-rivet then apply sealer.

Click to expand...

I'd do that too ...

I just bought an 8lb can of Goop Coat-it to reseal my 16 foot Fisher Marine jon. Interested if anyone has experience with this product or has any tips for applying it. It is going on the bottom and up to the waterline on the transom and sides. I am running a 40hp Merc jet.

FYI, I got a lead to this article today for fixing HOLES in our beloved tin boats using this flexible epoxy product. Might be of value to someone here ...

Pictures attached for the article posted above on that flexible epoxy product.

For those interested ... those pictures posted above were from 2007 and per West Systems, that hull repair is still sound. Again, if/when coating a NEWer hull with epoxy to prevent something from leaking, then purely for co$ts reasons I'd go with Steel-Flex or Coat-It, and for inside use maybe use GLuVit, but for spot repairs (like I needed) or repairing large holes in tin boats ... I think you'll find G-Flex a viable and permanent repair!

They also validated my use of a vinegar wash (Hey, I learned that on this site!) as well as zinc chromate priming before application of any epoxy product. FWIW here's a copy of the email I just received from their Customer Support:

Hi Dale,

Thank you for recommending G/flex in the forum, we certainly I appreciate it! It is the best option for fixing seams and rivets on aluminum boats.

I'm not sure if you've seen the video on our website of this type of repair (link below), but the boat in the video was repaired in 2007 using G/flex and it has not yet failed. This was one of the first boats repaired in this manner, so it's tough to estimate a time frame for failure in real world conditions when the first ones fixed are still going strong. The boat lives in Michigan so sees similar temperatures to your climate.

You actually went a step further with your surface prep by using the acid (vinegar) and Zinc chromate. That just means you achieved better adhesion to the aluminum than ours!

G/flex is much more flexible than Gluvit and our 105 System, so it is able to handle the expansion and contraction of the joint quite well.

Here's the video I mentioned:
https://www.westsystem.com/ss/fixing-leaking-rivets-in-an-aluminum-boat/

Here's an article of the repair if you'd like to share it on the forum:
https://www.westsystem.com/ss/assets/Uploads/FixSeamsGflex.pdf

Thanks for your questions, please let me know if you have any more.

Best Regards,

Mike Bxxxxx (Redacted by DaleH) | Technical Advisor
Gougeon Brothers, Inc.

Dale is this stuff still the way to go? I just ordered the G-Flex 650 kit off of Amazon. Not seeing any 12oz fiberglass fabric like they suggest using in the canoe repair article though. Any other replacement weight glass mat I should try to look for as an alternative?

wmk0002 said:

Dale is this stuff still the way to go? I just ordered the G-Flex 650 kit off of Amazon. Not seeing any 12oz fiberglass fabric like they suggest using in the canoe repair article though. Any other replacement weight glass mat I should try to look for as an alternative?

Click to expand...

Most makers sell a 10-ounce woven in rolls or flats. How much do you need? I have some, likely the heavy weight, and will send you some. But otherwise, yes - I myself have not seen another product I'd use in place of this (i.e., being a flexible epoxy).

DaleH said:

wmk0002 said:

Dale is this stuff still the way to go? I just ordered the G-Flex 650 kit off of Amazon. Not seeing any 12oz fiberglass fabric like they suggest using in the canoe repair article though. Any other replacement weight glass mat I should try to look for as an alternative?

Click to expand...

Most makers sell a 10-ounce woven in rolls or flats. How much do you need? I have some, likely the heavy weight, and will send you some. But otherwise, yes - I myself have not seen another product I'd use in place of this (i.e., being a flexible epoxy).

Click to expand...

I only have a small 1-1.5" crack I'm attempting to repair but I'm good with ordering a larger piece of mat and keeping it on hand for future needs. But thanks for the offer. I only searched on Amazon but I can try Raka or other online retailers. I just had trouble finding the 12oz they used in the repairs they describe. Is the weight in oz per a certain sq footage or inches?

I have an old 12' jon boat I use in my pond. It has had a rough life, dragged over rocks and up on sand beaches to the point where cracks were rubbed thru the ribs formed into the bottom. I used JB weld for a while but it started leaking after a couple years. About 5-6 years back the boat was leaking pretty bad so I searched for other ideas, stumbled across " leak stopper" a ckear brush on sealant used on exterior metal and roofing shingles. In my area you can get it at Home Depot and Tractor Supply. This stuff is awesome and tough!!! I brushed two coats on inside and outside bottom, then after it was thoroughly dry painted two costs of Rustoleum paint over the sealer. That was 5 years back....not one leak...still gets dragged overvrocks and up sandy beaches and dragged thru the yard with my 4 wheeler. Paint has worn off the ribs, but notbthe leak stopper!! This stuff is flexible but tough as nails. If you haveca tinnie with leaks try this stuff, cheaper than most other boat sealers and works very well !!