Boat Design Forums  |  Boat Design Directory  |  Boat Design Gallery  |  Boat Design Book Store  |  Thanks to Our Site Sponsors
  #1  
Old 02-05-2017, 09:59 PM
leaky leaky is offline
Junior Member
 
Join Date: Sep 2008
Rep: 14 Posts: 95
Location: nh
VE for barrier coating & protecting new hull from the inside?

Hi,

So I've got this kit boat I'm finishing, a 32 Holland (downeast). It's solid PE w/ a VE skin on the outside. In the process of closing things off I'd like to add some barrier coat in the inside and either across the whole bilge or in some areas, gel coat (will use an ISO) as an additional barrier and for cosmetics.

The purpose of the barrier coat is basically to keep engine oils, fuels, anti freeze, or whatever ends up in the bilge from getting seeped into the bare PE fiberglass. Also I understand sometimes blisters actually are triggered on the inside of the hull, so to me it makes sense to attempt to add some barrier simply for water.

I've never used VE before, I assume it's waxed or unwaxed like PE.. my initial thought is to prep the area, roll a couple coats of unwaxed VE onto the area, then a couple coats of unwaxed gel coat, followed by PVA to promote full cure. Is this sane?

The reason I'm looking to use these resins, versus an epoxy or bilgecoat, is I'd like to keep things in a more bondable state should I realize I want to add structures or bulkheads in the hull, ie I can grind into or through gel coat but if it's well bonded and a little bit is suspended in the joint it's not going to harm a future bond of VE or PE much. If I use epoxy or paints then I'll literally need to remove the entire coating in order to bond later with a VE or PE.

My finish work will be using PE for non-critical and reasonably repairable areas and VE for critical structures or things that would be very difficult to go back and repair.

I attached an outside and inside picture for a little info on the project. Right now I'm about to buy the engine & transmission - the mock of which is going to dictate how to complete the engine bed structure, however when I get there, before installing the engine I need to do my coating.

Thanks in advance for you .02!

Jon
Attached Thumbnails
VE for barrier coating & protecting new hull from the inside?-smallwholeboat.jpg  VE for barrier coating & protecting new hull from the inside?-smallinside.jpg  
Reply With Quote
  #2  
Old 02-05-2017, 11:32 PM
ondarvr ondarvr is offline
Senior Member
 
Join Date: Dec 2005
Rep: 506 Posts: 1,312
Location: Monroe WA
While it may help, I'm not sure I've ever seen a blister issue on the inside of a hull, so while making you feel better, it may not do much more than that.


You could easily roll on a coat or two of VE, but you need to make the layer thick enough to actually be of some value, which is thicker than what you could apply it without a fabric of some type to keep it from sagging and cracking (resin viscosities are low), but you can also use a VE gel coat along with it. There are VE Barrier coats that can be built up easily and will cure tack free without using wax or PVA (wax is better than PVA in this application), so that's an option.

The area you need to cover wouldn't be that large, only the areas where water would sit long term would be candidates for blistering (if it's a real concern). so not much would be needed.
Reply With Quote
  #3  
Old 02-06-2017, 12:26 AM
leaky leaky is offline
Junior Member
 
Join Date: Sep 2008
Rep: 14 Posts: 95
Location: nh
Thanks!

Who's VE gelcoat do you like? I see a few places sell it but they are mostly used in tooling, so I wonder if they tend to be real brittle? I know some of the good PE gel coats are far less porous, maybe I should just plan on giving it 2 layers of good quality gelcoat, like ArmorCote or something, and call it a day?

On blisters what I've been told is basically the outside blisters can be created by the inside standing water... Sounded plausible to me given blisters are kinda vodoo anyway - but maybe it's total BS.

More importantly though is I want some barrier against all the various nasty fluids and for cosmetic/cleaning purposes. If I have an accident changing oil, fuel leak, hydraulic leak etc.. I want something there to keep it from setting into the bare fiberglass at least. And ideally whatever is there is a long lasting & potentially bondable surface, versus a paint.

Most of the sub deck areas will be accessible, either because there is rigging to get to there or a storage locker. To me it makes sense once I'm ready to put the deck on just to roll a complete coating on; if nothing else it will look nice.. When the deck is on I'll be rolling the same right up under the gunnels.

Jon
Reply With Quote
  #4  
Old 02-06-2017, 06:50 AM
ondarvr ondarvr is offline
Senior Member
 
Join Date: Dec 2005
Rep: 506 Posts: 1,312
Location: Monroe WA
Blisters tend to form in the laminate near the surface of the exterior of the hull, this is from water migrating through the gel coat. If the same thing happened from the inside the blisters would be near the surface in the bilge, not on the outside of the hull.

Given enough time water will permeate the entire laminate, but it takes a very long time for blisters to form deep in a laminate.

The VE tooling products wouldn't be a good fit, and normal VE gel coats are tough to find. This type of product can be used for that purpose though.

http://duratec1.com/pdf/DS%201794-006.pdf
Reply With Quote
  #5  
Old 02-06-2017, 08:38 AM
leaky leaky is offline
Junior Member
 
Join Date: Sep 2008
Rep: 14 Posts: 95
Location: nh
Thanks!

Yes that looks like the right sort of stuff. States in the manufacturers technical literature that it is high build, resistant to cracking, and has great chemical and solvent resistance, which is what I'm going for.

Jon
Reply With Quote
  #6  
Old 02-06-2017, 12:22 PM
Stumble Stumble is offline
Senior Member
 
Join Date: Oct 2008
Rep: 739 Posts: 1,875
Location: New Orleans
The other option is to just epoxy coat the inside. If you ever need to bond to that, then just use more epoxy. It's out of the sun so UV shouldn't be an issue.
__________________
Greg Rubin
Captain-Attorney-Boat addict
Reply With Quote
  #7  
Old 02-06-2017, 12:41 PM
leaky leaky is offline
Junior Member
 
Join Date: Sep 2008
Rep: 14 Posts: 95
Location: nh
Quote:
Originally Posted by Stumble View Post
The other option is to just epoxy coat the inside. If you ever need to bond to that, then just use more epoxy. It's out of the sun so UV shouldn't be an issue.
Yes I hear you on that, and if I ever had to make a serious repair it'd be with epoxy.. I really like epoxy for many things.

With this boat though I want to try to maintain the easy gel coat options and not have to question and test paints. Epoxy is great stuff until it comes time to paint it. It's easier to stick with one system, all epoxy or all PE/VE.

Jon
Reply With Quote
  #8  
Old 02-07-2017, 02:52 AM
gonzo's Avatar
gonzo gonzo is offline
Senior Member
 
Join Date: Aug 2002
Rep: 2031 Posts: 11,847
Location: Milwaukee, WI
Epoxy paint will have good adhesion on polyester and vinylester resins. It is much easier to apply paint than gelcoat. Also, it is less porous, so easier to keep clean.
__________________
Gonzo
Reply With Quote


  #9  
Old 02-07-2017, 10:55 PM
leaky leaky is offline
Junior Member
 
Join Date: Sep 2008
Rep: 14 Posts: 95
Location: nh
gonzo - thanks for that too.

I'm not familiar with epoxy paint, what would you recommend? Is it a 2-part and to epoxy what gel coat is to PE? Is it UV resistant or similar to epoxy & VE with problems in that respect?

I don't think I want to go that route, for the same reason I want to avoid using epoxy as the barrier. It's just nice to keep it to one system that is always a bondable surface.

For instance if I realize after the fact I want to add a bulkhead or tab into something on the hull, and am working in a tight space after the deck is on, I would like not to have to completely grind through the top layer of roving in order to remove a paint that is in the crevices. With a VE or PE based "gelcoat" I'd still do a good prep and try to grind it away with a 40 grit in the orbital, but a little left there shouldn't hurt my bond so wouldn't need to go crazy.

Jon
Reply With Quote
Reply



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Barrier coating behind the gel coat tell me please ! tunnels Fiberglass and Composite Boat Building 24 02-18-2011
04:01 AM 
Coating inside keel zulpas Metal Boat Building 2 10-08-2010
11:47 AM 
Stitch & glue outrigger to glass inside or not? erikhaha Multihulls 90 06-23-2010
06:08 AM 
Bondo hull coating EASI54 Metal Boat Building 15 09-25-2005
08:32 AM 
barrier coating epoxy fastests10 Boatbuilding 0 08-12-2002
10:01 PM 

Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.

All times are GMT -5. The time now is 10:12 PM.


Powered by: vBulletin Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Web Site Design and Content Copyright ©1999 - 2017 Boat Design Net