Cruisers Forum
 


Join CruisersForum Today

Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 08-03-2020, 15:10   #16
Registered User

Join Date: Sep 2019
Posts: 122
Re: Does my hull still need a barrier coat

My preferred system.That I have used on my own boats Polyester Vinyl ester and Epoxy. Wash and scrub the newly finished hull coating with a strong soap (Simple Green or equiv ) twice end to end . pressure wash with clean fresh water. Dry ---wait for a good weather forecast. While waiting get enough low Viscosity clear epoxy and epoxy soluble colour in three contrasting shades . Divide up the epoxy in three or multiples of three containers with appropriate carefully weighed Hardner . And mix very thoroughly each the colors A B C Early in the day make sure the hull is dead dry amix the first coiour with its hardner split into three big roller trays have a helper with a long handled roller and one for you . Uncover a tray or two Depending on the size of the boat start at different ends on the shaded side and thoroughly roll on a coat. --- Go back over check for holidays clean up get a snack!. As soon as the starting point is hard enough so
your roller will not move it do the next coat etc etc . The final coat will harden a lot quicker thanks to the exotherm of the first two .Give it two days to harden then pressure wash it with a scrub brush and detergent to remove and "Amine Blush" and when that dries you are ready for bottom paint. Works for me! Mike Pope Only have to do it once WELL!
__________________

Michael Pope is offline   Reply With Quote
Old 08-03-2020, 17:53   #17
Registered User

Join Date: Dec 2018
Posts: 98
Re: Does my hull still need a barrier coat

Quote:
Originally Posted by Wind River View Post
After an osmosis treatment of peeling my hull and re-glassing with 2-3 layers of 1708 and epoxy resin, is there still a benefit or a need for the recommended 5 coats of barrier coat?
Better hope the hull structure was thoroughly dry before sealing it up like that. Hard to accomplish in many situations.
__________________

Happydrv is offline   Reply With Quote
Old 08-03-2020, 18:41   #18
Registered User

Join Date: Sep 2019
Posts: 122
Re: Does my hull still need a barrier coat

My advice will probably not be popular --- bur honest--- Paint companies are not interested in selling a paint that is guaranteed as the ultimate water vapour barrier regardless of cost. Paint companies would like to show a profit so they make a paint out of reasonably cheap materials that are stable in price and that are just a bit better than the other guys and a bit easier to handle and apply .
They can add pigment and filler neither of which help the primary function.
Plain clear high solids Epoxy is the best available vapor barrier so use it. Add just enough colour to help you to assure coverage and thickness. I do not think there is any reason to use more that three coats actually two coats for thickness and one for what you missed as it is easy to miss because you are going over a multi coloured shell. But yes If you can use clear epoxy. especially on the bottom . Topsides are different you need colour to abate the UV . This is all assuming that you have faired out the lumps and bumps and have beautiful shape. Why did you out all that glass on was the structure lacking!. If the polyester is sound a couple of layers of ten ounce Glass cloth goes on a lot smoother and quicker and comes in wide material. Too Late. Yeh ok. My opinion for what it is worth Cheers you will feel better once it is done. Michael Pope
Michael Pope is offline   Reply With Quote
Old 09-03-2020, 07:02   #19
DoÖ or do not
 
s/v Jedi's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 10,440
Re: Does my hull still need a barrier coat

My response was about a boat that has never had anti fouling and was stored on a trailer whenever not sailing... but now going to be in the water and have anti fouling for the first time. I have assumed the boat has no blisters.

For that boat, adding an Interprotect2000 barrier coat is the best thing to do for the boat. Without it, the boat may not ever get blisters, but with it, you minimize the risk.

That gelcoat is a good barrier coat and all you need is not true. Thousands of blistered boats to support that.

That just plain epoxy is the best barrier coat is not true. Itís better than other resins, but even West System recommends and sells a special additive for use as barrier coat. While I believe that is a very good system, Interprotect 2000 is much easier to use and itís protection is as good or may be even better.

That a barrier coat can seal moisture in and make things worse is true. Before doing this, a hull needs to have a completed osmosis treatment incl. the drying phase. This is something that gets measured with a meter, not decided upon by wise men on the Internet

If your boat has been in the water for years but you donít have blisters and want to add a barrier coat, then do a very close inspection for blisters right when the boat is hauled. An hour later they may be invisible again. Then strip all paint to get to the gel coat, do daily pressure washes and measure moisture level before that daily wash. When the numbers stop going down and the level is within the acceptable range according to application instructions, youíre good to go.
s/v Jedi is offline   Reply With Quote
Old 09-03-2020, 09:19   #20
Registered User
 
Wind River's Avatar

Join Date: Oct 2012
Location: San Diego
Boat: Hudson Force 50 Center Cockpit
Posts: 330
Re: Does my hull still need a barrier coat

I am glassing the hull in a couple of weeks.

The hull was peeled almost two years ago, sand blasted 7 months ago and has been pressure washed 12 times. Short of a hot vac system, I think I have done all I can do.

Moisture readings have dropped to levels of the lowest above water line readings, except in the area of the keel which I am told can vastly skew the readings of the meter. They are still half of what they were before I started though.

Should be good to go!
Quote:
Originally Posted by Happydrv View Post
Better hope the hull structure was thoroughly dry before sealing it up like that. Hard to accomplish in many situations.
__________________
Follow my refit on Facebook at S/V Wind River.
Wind River is offline   Reply With Quote
Old 09-03-2020, 10:40   #21
Registered User

Join Date: Dec 2018
Location: Wichita/Pensacola
Boat: Lagoon TPI 37'
Posts: 197
Re: Does my hull still need a barrier coat

Quote:
Originally Posted by Wind River View Post
I am glassing the hull in a couple of weeks.

The hull was peeled almost two years ago, sand blasted 7 months ago and has been pressure washed 12 times. Short of a hot vac system, I think I have done all I can do.

Moisture readings have dropped to levels of the lowest above water line readings, except in the area of the keel which I am told can vastly skew the readings of the meter. They are still half of what they were before I started though.

Should be good to go!
I am always amazed of the power of a dehumidifier draining into the sink. For several years, I have placed a dehumidifier on the galley counter and drained into the sink. I have also pulled up my floor boards above my bilge. The dehumidifier actually pulls the water out of my bilge. It is completely dry when I return. I wonder if a dehumidifier could suck the water out of your keel/hull from the inside. I only say this because we can't control the weather outside but if we can control the inside, it may dry your boat out faster.
My painter needed to paint my topsides but it was alittle chilly for Awlgrip. We placed heaters inside until the hull was warm to paint. It worked fine.
sailingchiro is offline   Reply With Quote
Old 09-03-2020, 10:43   #22
Registered User
 
Cheechako's Avatar

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 22,041
Re: Does my hull still need a barrier coat

Not as far as I'm concerned. You just need a coat on the epoxy resin to bond the bottom paint to though.
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is offline   Reply With Quote
Old 23-03-2020, 07:34   #23
Registered User
 
Steve DAntonio's Avatar

Join Date: Jun 2018
Location: Virginia
Posts: 49
Re: Does my hull still need a barrier coat

When I managed a yard I supervised well over a hundred peel and re-lamination jobs, our preferred material was vinylester resin and fairing compounds as it's every bit as effective as epoxy, but easier to work with. Regardless, provided the skin coat is thick enough, 1/10" is required for VE, VE and epoxy are for the most part immune to osmotic blisters, so strictly speaking no barrier is needed. However, we still applied a barrier, Interlux Interprotect 2000 for two reasons, one it was a belt and suspenders approach (we offered a 10 year warranty against reappearance of blisters, one we never had to act on in my 11 years there), and two, the barrier is an excellent primer for anti-fouling paint, far better than the cured epoxy or VE resin, or fairing. If the bottom paint is applied within the chemical application window, you will achieve a chemical bond, which is more tenacious than the mechanical bond achieved by sanding applying anti-fouling paint over a cured surface like gelcoat or VE/epoxy resin. In short, the barrier adheres to the new bottom very well, and the bottom paint adheres to the barrier very well. The bottom still needs to be profiled before applying the barrier. Use anti-foulant that is made by Interlux and known to be compatible with Interprotect, there are many from which to choose, my preference is for an ablative.

Interprotect says that if Interprotect 2000 is used as a barrier you need roughly five rolled on coats (we applied with an airless to achieve 10 mils dry, and a very smooth finish). If used strictly as a primer, only 1-2 coats are needed, but once geared up I'd recommend the full 10 mils. Instructions here http://www.yachtpaint.com/MPYACMData...Y+20141215.pdf

This article describes the process https://stevedmarineconsulting.com/w...nd-Osmosis.pdf

On the subject of osmosis repairs in general...polyester resin and polyester based gelcoats are poor barriers to moisture (isophthalic or iso resin is more blister resistant than orthophthalic resin, but it's not blister-proof), however, it's not that simple, as the above article explains, water migration into the laminate is just the first step in the process, once the water is there if it then encounters water soluble materials or WSMs, usually starch-based binders, the reaction that ensues creates pressure, and the symptom, blisters. I've encountered boats with bottoms that pegged a moisture meter and yet had no blisters, and I've encountered moderately wet bottoms that were riddled with blisters.
Furthermore, based on my first hand experience and research, for two reasons it is impossible to "dry out" a bottom that has absorbed moisture. One, two of the byproducts of osmosis are acetic acid (that why burst blisters small like vinegar) and glycol, neither of which evaporate at atmospheric pressure, so even if you can get water to evaporate from a FRP laminate, admittedly a stretch, these chemicals will remain, and continue to react with the WSMs. The acetic acid also attacks resin, causing "fiber whiting" which, when peeled, is often mistaken for incomplete wet-out, the acid is in fact slowly disassembling the resin's structure.

Please don't let anyone charge you to remove gelcoat, "dry" a bottom with tenting and dehumidifiers, individually fix blisters, and barrier coat, at least not as anything other than a short term, cosmetic fix. If an osmosis repair doesn't include at least a 5, and preferably 10, year warranty, it's probably not going to be long-lasting. Again, you may still choose that route, as long as you understand that going in. Those quick "repairs" should be far less expensive than a full peel (and the peel must go down to unaffected laminate, that's determined with a patch test, see the article), which is laborious and requires significant skill. It must also include removal of all bottom hardware, thru-hulls, strut etc, to achieve a proper peel and re-lamination.
__________________
Steve D'Antonio
Steve D'Antonio Marine Consulting, Inc.
ABYC Certified Master Technician
Steve DAntonio is offline   Reply With Quote
Old 23-03-2020, 07:40   #24
Registered User

Join Date: Jul 2010
Posts: 19
Re: Does my hull still need a barrier coat

Of all marine coatings Interprotect 2000e is way up on the list (of best products). After all the work you have done the Interprotect will be a breeze. Satisfying also. It can be sourced for about $85.00 if you shop. It's simply a primer and has great adhesion to "clean" surfaces. The best part that $250.00 dollar a gallon bottom paint will stick to it. Good luck and keep us posted
moonmist is offline   Reply With Quote
Old 23-03-2020, 08:37   #25
Registered User
 
mf70's Avatar

Join Date: Oct 2014
Posts: 36
Re: Does my hull still need a barrier coat

Seems like a lot of posters didn't read the text of the post. I did exactly what you did and barrier coated with Interprotect 2000 many years ago. The I2000 is a hard surface that provides a solid base for the paint layers. Follow s/v Jedi's coating advice for first bottom paint coat.
__________________
"Sanderling" 32' Sharpie Ketch
mf70 is offline   Reply With Quote
Old 25-03-2020, 14:50   #26
Registered User

Join Date: Mar 2020
Posts: 1
Re: Does my hull still need a barrier coat

Hello, Similar Question: A guy was blasting paint off my boat, and he went all the way down to the fiberglass in one, small, 3 by 4 inch spot. I had planned to just ad primer over the whole boat (Interprotect 2000E) now and then paint it again, but what should I do about the spot. Because it's so small, does it require really nice gel coat fix up now? Thanks for helping a beginner if possible (in layman's terms). MANY Thanks in advance for any help (any specific products/links you know of would be great along with your advice).
SV Newbie is offline   Reply With Quote
Old 25-03-2020, 15:14   #27
Registered User
 
mf70's Avatar

Join Date: Oct 2014
Posts: 36
Re: Does my hull still need a barrier coat

As they say, YMMV. Any underwater fairing compound will smooth the divot out. As to priming the hull, how dry is the fiberglass? Is there any hint of blistering? If the hull is dry and solid, Interprotect 2000 will make a good primer, as discussed above. If it's wet, the I2000 will seal the water IN, and blisters will appear underneath.
__________________
"Sanderling" 32' Sharpie Ketch
mf70 is offline   Reply With Quote
Old 25-03-2020, 15:39   #28
Registered User

Join Date: Sep 2014
Location: Fiji Airways/ Lake Ontario
Boat: Want a B430!
Posts: 1,388
Images: 10
Re: Does my hull still need a barrier coat

Steve DAntonio, that was the best article Iíve ever read on a boat forum. Packed with info and well written. Thank you sir! That was inspirational.
Tetepare is offline   Reply With Quote
Old 25-03-2020, 15:50   #29
DoÖ or do not
 
s/v Jedi's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 10,440
Re: Does my hull still need a barrier coat

Quote:
Originally Posted by SV Newbie View Post
Hello, Similar Question: A guy was blasting paint off my boat, and he went all the way down to the fiberglass in one, small, 3 by 4 inch spot. I had planned to just ad primer over the whole boat (Interprotect 2000E) now and then paint it again, but what should I do about the spot. Because it's so small, does it require really nice gel coat fix up now? Thanks for helping a beginner if possible (in layman's terms). MANY Thanks in advance for any help (any specific products/links you know of would be great along with your advice).
Test the hull for moisture levels. Do daily pressure wash. Do not start sealing before moisture levels are down into acceptable range.

That bare glass spot: just mix some West System (or MAS, Total Boat etc.) and brush it over that spot to seal the laminate. After cure, wash with water and Scotchbrite sponge (donít skip this), then sand to prep for barrier coat.
s/v Jedi is offline   Reply With Quote
Old 25-03-2020, 18:42   #30
Registered User
 
Steve DAntonio's Avatar

Join Date: Jun 2018
Location: Virginia
Posts: 49
Re: Does my hull still need a barrier coat

Quote:
Originally Posted by SV Newbie View Post
Hello, Similar Question: A guy was blasting paint off my boat, and he went all the way down to the fiberglass in one, small, 3 by 4 inch spot. I had planned to just ad primer over the whole boat (Interprotect 2000E) now and then paint it again, but what should I do about the spot. Because it's so small, does it require really nice gel coat fix up now? Thanks for helping a beginner if possible (in layman's terms). MANY Thanks in advance for any help (any specific products/links you know of would be great along with your advice).
Re-applying gelcoat...don't do that, there are far better ways to block moisture migration into a laminate, Intrprotect is one of them. If there is a depression here I'd fill and fair using a vinylester-based (you could also use West, but as note earlier epoxy is a bear to sand, and no better than VE for filling/blocking water entry) below the waterline filler, then Interprotect the whole bottom.

To reiterate, you cannot "dry" a laminate that is "wet". Permanent solutions require removal of affected laminate, usually by peeling, re-laminating, my preference is for VE resin, and then fair, and barrier/prime coating with Interprotect. That will result in a permanent osmosis fix.
__________________

__________________
Steve D'Antonio
Steve D'Antonio Marine Consulting, Inc.
ABYC Certified Master Technician
Steve DAntonio is offline   Reply With Quote
Reply

Tags
hull

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Do I Really Need an Epoxy Barrier Coat ?! Help Needed ASAP ! windtraveler Construction, Maintenance & Refit 29 14-01-2013 15:44
Yellow Steel Hull Barrier Coat Gnarl Construction, Maintenance & Refit 2 06-03-2012 23:38
Do I Need a 'Barrier Coat' ? mestrezat Construction, Maintenance & Refit 10 18-08-2010 19:31
Epoxy barrier coat and blisters StoutWench Construction, Maintenance & Refit 10 02-08-2005 20:28

Advertise Here


All times are GMT -7. The time now is 01:54.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.