Gluvit under Steelflex - Good Idea?

[Windman7]

I was just reading the info on Gluvit. All the post on here refer to it as being used on the inside to seal against leaks and Steelflex on the outside of the boat for protection. Why can't Gluvit be used on the outside for sealing and coated over with Steelflex for protection? Seems like the Gluvit would provide a little give for the Steelflex with boat flex. Has anyone tried this? Does this seem like a problem?

 

[Brine]

In my opinion, Steelflex does little for "protection". It's simply a slick epoxy coating. I like that it probably helps in winching the boat up on carpeted bunks for those that don't get to powerload their boats with an outboard. On riveted boats, the consencus has been that Gluvit works best as a penetrating sealer on the inside. I've seen it used on the outsided of fiberglass boats/canoes on rivers as hull protection via the internet, but have no first hand experience with it.

 

[Windman7]

My thought was to Gluvit on the inside and the outside to make waterproof and Steelflex over the Gluvit for the outer coat. It appears Gluvit is the best at sealing the seams and rivets and seems good to do on both inside and outside. Will Steelflex stick to the Gluvit?

 

[Brine]

I wouldn't bother with the steelflex then. You have to aggressively scuff up the surface for it to bond to bare aluminum, so I would assume you'd be putting on gluvit, then removing it (ala agressive scuffing" to have it bond.

 

[plt3145]

Windman7, I had the same thought, well sort of! Coat-it or Gluv-it on the underside of the hull and then priming bare aluminum spots where the Coat-it was not needed and then painting. I have carpet in 12 ft floater from the previous owner and really did not want to take up. I have no leaks but the seams on the bottom seem a little gappy to me. Brine, in your opinon, will Coat-it or Gluv-it on the exterior of the hull still allow for good paint adherence?

 

[Windman7]

The Gluvit site said it just needed rough sanding and it can be painted.

 

[Brine]

Windman7, I had the same thought, well sort of! Coat-it or Gluv-it on the underside of the hull and then priming bare aluminum spots where the Coat-it was not needed and then painting. I have carpet in 12 ft floater from the previous owner and really did not want to take up. I have no leaks but the seams on the bottom seem a little gappy to me. Brine, in your opinon, will Coat-it or Gluv-it on the exterior of the hull still allow for good paint adherence?

I have no first hand experience with either product. I'm only passing on info I read on Gluv-it when I was debating on using it. The overwhelming opinion was that it was best used on the inside of an aluminum, riveted hull. I used Steelflex on the exterior. I'd save the money for something else.

 

[Mojo^]

Yes, Gluvit inside and Steelflex outside. To get good adhesion with Steelflex you really need to be aggressive with scuffing the bare surface of the aluminum hull. I used 80 grit on a DA sander. Gluvit isn't going to take kindly to that kind of abuse. Once you use these products, you'll understand why. Even though I used both products with my boat I have since come to the conclusion that it was complete overkill but if that puppy leaks I will know for certain that it is the will of God for it to do so.

 

[Windman7]

Thanks for the input. My thought was to double the sealing factor with the Gluvit to insure water tightness. Several post mention that Steelflex doesn't seal as well. I'm guessing from your comment and others that one coat of Gluvit on the inside is sufficient to seal the boat.

 

[Mojo^]

Gluvit does work very if you get the aluminum very clean. It has zinc chromate in it and will adhere to clean aluminum and help with corrosion. Make sure you mix it very well before applying. The down side is that it is expensive. I used it on the inside to seal all rivets that attach stringers and in any seams. The Steelflex will have to take care of the rest. I'm a belt and suspenders kind of guy and feel better knowing that I the boat is sealed inside and out even though using onlyGluvit would have been just fine. Be aware that Gluvit does not have any additives to prevent breakdown from UV so you will have to paint over it.

 

[Windman7]

If gluvit seals the inside, would an epoxy paint be sufficent for the outside?

 

[Windman7]

You mentioned really cleaning the aluminum before applying the Gluvit. How can you clean the crevices and crannies you can't reach. Seems like these are the most important areas to get prepped.

 

[Mojo^]

Alumaprep No. 33 cleans aluminum like nothing I've ever seen. Skygeek and aircraftspruce carries it. I think Jamestown Distributors also has it.

Steelflex is an epoxy so yeah, I guess any good epoxy should be fine.

 

[Windman7]

Does the Alumaprep chemically clean the aluminum? Will it remove the old paint?