I need a below waterline sealant that is not 5200

[FL2AK]

What can I use as a below waterline sealant that is NOT 3M brand 5200, but is every bit as effective and durable as 5200, but doesn't require humidity to cure?

Last week I replaced about 10-12 No 5 flush rivets in the side of my Grumman Sport Boat. After installing the new rivets, I used a thin coat of 5200 on the inside and outside of the hull at each rivet as an extra measure against future leakage. I've left the boat in the garage at about 68 degrees; today was the 7th full day of cure time.

And the sealant is STILL TACKY and doesn't want to cure.

I did some reading here and other sites and found that 5200 requires a minimum 50% humidity to cure. (I thought the package markings of 50% humidity at 70 degrees were "ideal" conditions, not "minimums.") Humidity in my garage was 24%, so I cranked the heat in the garage and started adding water to try to raise the humidity, but I just can't get the humidity up high enough. Garage is currently 90 degrees (which, that alone probably cost me $50 in natural gas), the humidifier has run through 5 gals of water, I've dumped 10 gals of water in the boat, most of which has evaporated in the past 12 hours, and all I've done is raise the humidity from 24% to 33%.

I guess I'll have to take Anti Bond or MEK and strip all this sealant off and start over.

What can I use that doesn't require humidity to cure, and maybe even will cure in less than a week, but seals as good as 5200?

 

[sphelps]

Don't they make a fast cure 5200 ?
Did you try a misting of water with a spray bottle ?

 

[ondarvr]

Some of the products we sell are moisture cure, when working in low humidity locations we either spray a light mist of water over the surface, or lay a damp paper towel over it.

 

[Bondo]

What can I use as a below waterline sealant that is NOT 3M brand 5200, but is every bit as effective and durable as 5200, but doesn't require humidity to cure?

Last week I replaced about 10-12 No 5 flush rivets in the side of my Grumman Sport Boat. After installing the new rivets, I used a thin coat of 5200 on the inside and outside of the hull at each rivet as an extra measure against future leakage. I've left the boat in the garage at about 68 degrees; today was the 7th full day of cure time.

And the sealant is STILL TACKY and doesn't want to cure.

I did some reading here and other sites and found that 5200 requires a minimum 50% humidity to cure. (I thought the package markings of 50% humidity at 70 degrees were "ideal" conditions, not "minimums.") Humidity in my garage was 24%, so I cranked the heat in the garage and started adding water to try to raise the humidity, but I just can't get the humidity up high enough. Garage is currently 90 degrees (which, that alone probably cost me $50 in natural gas), the humidifier has run through 5 gals of water, I've dumped 10 gals of water in the boat, most of which has evaporated in the past 12 hours, and all I've done is raise the humidity from 24% to 33%.

I guess I'll have to take Anti Bond or MEK and strip all this sealant off and start over.

What can I use that doesn't require humidity to cure, and maybe even will cure in less than a week, but seals as good as 5200?

Ayuh,..... 5200, or any other caulkin' compounds don't do squat when slathered over the outside of things,...

It's Designed to work when In-between things,...

It's not a surface coatin', it's a caulkin' compound, for sorta formin' a gasket,... Between things,...

 

[GA_Boater]

Gluvit or Coat-it would be a better choice for interior rivet sealing, Interior because UV degrades either one.

5200 or 4200 is best used like Bondo said, squished between stuff. A plop of 5200 on the rivets before squeezing is one use. Slow cure does take 7 days to cure, even in recommended temp and humidity range.

If you use sealant on the rivets and the right sealer on the inside, you don't need to slather anything on the outside of the hull except paint.

BTW - Here is a short Gluvit discussion - http://forums.iboats.com/forum/gene...920-factory-sealant-on-riveted-aluminum-boats

Good luck.

 

[FL2AK]

I put the stuff on the rivet itself before installation as well. I can only assume that that is not curing, either. As far as interior use and susceptibility to UV, It's an open boat (Grumman Sport Bpat, so essentially a square stern canoe); there is no place on the boat that is sheltered from UV. I'll try the wet paper towel route. Nothing to loose.

So, sounds like there is no below waterline sealant that doesn't require humidity?

 

[ondarvr]

There is, but don't give up on what you have already done, it will cure, eventually. Is it just tacky, or completely soft and runny?

The biggest issue with 5200 is that the tube is only good for a short time after it's opened because it will cure solid over time. And a common complaint is how slow it is.

 

[GA_Boater]

The 5200 will cure. Mist it with water periodically and it will help. Turn the heat down. Even if it's tacky, it's still sealing.

Why not give it a chance to cure and try her in the water. If you have leaks, go from there. You could put a coat of paint inside if you end up with Gluvit or Coat-it.

I head if you keep the left over 5200 in the freezer, it extends the life of an opened tube.

 

[alldodge]

From what I have found is that 5200 is not for below the water line, 4000 is.

 

[GA_Boater]

3M says 5200 and 4200 are both for above and below the waterline. The major difference is permanence, kind of like LocTite Red and Blue. 5200 is permanent, 4200 isn't.

 

[alldodge]

Just info and where I found it from BoatUS
http://www.boatus.com/magazine/2013/April/how-to-pick-the-right-sealant.asp

 

[jigngrub]

It'll eventually setup and cure, and Murphy's law says the stuff in the tube will set and cure before the stuff on the boat.:lol:

For future reference, I like the Lok-tite marine epoxy for a rivet dip, it'll setup under water or out in the middle of a desert.

Painting over UV sensitive materials will protect them from exposure breakdown.

 

[GT1000000]

Uh, put the boat in the water and it should be just fine...

 

[FL2AK]

Thanks for your encouragement. After running the room dehydrator in the garage full blast for 24 hrs (ran through about 15 gals of water) I've got the humidity up to 43%. Stuff does seem "less tacky." And yes, it's tacky, not runny. I have to get the boat out of the garage by Sunday midday no matter what. But it has warmed up to 40 degrees outside now. (but still very dry outside.) So I guess I'll just let it sit and see what happens.

Out of curiosity, if it remains tacky (for weeks and weeks for example) at what point do I remove it and start over? For example, if it's still tacky after 2 weeks, a month, longer?) When should I say "that's it, it isn't going to cure."?

Oh since someone asked, it was a brand new, unopened tube, purchased the day before I did the work. (And I think I already tossed the tube.)

 

[jigngrub]

Out of curiosity, if it remains tacky (for weeks and weeks for example) at what point do I remove it and start over? For example, if it's still tacky after 2 weeks, a month, longer?) When should I say "that's it, it isn't going to cure."?

Somewhere around July.... don't worry, it'll setup and cure. 5200 regular formula is pretty aggravating with it's long set and cure time to go along with being a runny drippy mess, that's why I like the Lok-tite marine epoxy. It comes in a couple of different set times, a 5 minute fast and a 2 hr version for an extended work time.

 

[pauloman]

use an aluminum MCU coating like aluthane or por 15 -

 

[Watermann]

I've used probably 2 or 3 construction tubes of 5200 in my builds and have affectionately heard it called "Pelican Poop". I've found it lives up to it's moniker. :lol:

It will cure and seal out that pesky water don't worry. I've used a boat a few days after using 5200 on rivets for a transducer mount and nothing made it through. I think the lake helped it cure even.

 

[FL2AK]

Well. I leak checked it using water inside the boat, and it appears to have sealed completely. The inside sealant is completely tack free, but the outside sealant is still tacky. That sucks because I wanted to etch the exposed aluminum with AlumaPrep 33 and then treat it for corrosion prevention with Alodine before painting it with zinc chromate. Looks like that isn't going to happen; the outside sealant likely won't be dry and I don't think painting over tacky sealant is a good idea. At least I know the boat will be useable once the ice on the lakes clears.

 

[jigngrub]

As already mentioned, keep the outside wet by spritzing water on it and you should be good to go in a day or two.

 

[jc55]

I've been using quite a bit of 4200 and 5200. After application of the 5200 and things are drawn tight...hatches, fittings, thru-hulls, screws, rivets, etc. I take some acetone on a cotton t-shirt and wipe around the item in question. The only 5200 left is the barely visible and inaccessible white ring of 5200. At that point, you shouldn't be able to tell if it's tacky. That's when I'd proceed with your paint plan.