Bottom Paint

[Kurth]

I've been lurking around for a while siphoning off great bits of wisdom (great forum, btw). Today we finally took the plunge and purchased our first Grady White, so I figured I should register and officially say hi.

Of course, I also have a question (with many more to come most likely).

Our new boat is a 2002 Grady White 208 Adventure. The boat is pristine, and since it was primarily used in fresh water and wasn't stored in the water, it's never been bottom painted.

We're going to keep the boat at a mooring (May - September) off Boston's North Shore.

What would you recommend as far as bottom painting goes? What paint, how many coats, barrier coat, etc? Also, what should I expect to pay for this, and how often will it need to be repainted?

Thanks in advance!

 

[seasick]

If you are going to do it, do it right.
Surface prep and dewax, 4 coats of 2002E barrier coat and two coats of ablative anti-fouling such as Interlux Micron.
Anything under $1200 sounds like a good deal. Business is slow so you may get a better price. Ask questions, the stuf has to be applied correctly, recoat times, etc. Costs will be higher if there are blisters or other issues. Additional costs for hauling and setup for painting.

Good luck with the 208..

 

[CJBROWN]

Welcome to the forum. You've picked a great boat :wink:

I keep debating whether to put mine in a slip instead of keeping it on the trailer. Obviously, there are pro's and con's to both. And with the slow economy it's a lot easier to get a slip right now.

But alas, I keep putting it off because I just can't stand the idea of putting paint on a hull that looks brand new, the boat is still pretty much perfect. I think it depreciates a boat by at least the cost of a paint job, probably more. And they don't look nearly so nice on the trailer with paint, ours gets towed up and down the coast and across the state to the Colorado River Lakes.

Since you've resigned to slip her, particularly for a short season, I would think a couple of coats of Interlux bottom paint, the kind made for new glass hulls should be sufficient. When I researched it I understood the paint was ready to apply, there's even a no-sand option on one of them. And I figured I could do it on the trailer, then jack it up and hit the areas where the bunks are. I estimated a couple of hundered bucks max to do it myself. I've been around boats for more than 40 years and we always did the bottom ourselves. I even had a 40' wood boat when I was in the NW.

I'm not in a place to debate the need for a barrier coat of epoxy. I thought the new hulls were okay as they were. Perhaps mr. seasick or others could expound on the need for an epoxy barrier coat on a new hull.

Anyway, yeah, it'a s great site, tons of info, and a super nice bunch of Grady owners from all over the country (and few other countries too!)

 

[gradyfish22]

You need to barrier coat the bottom, as mentione dabove, 2002E barrier coat is the way to go, interlux sells a kit to do it right. This insures your hull is sealed, over time a hull that is not sealed will begin to absord water into the poors of the gelcoat if not protected correctly, you will add additional weight over time and down the road risk having hull issues which are not typical, but possible. The alternative is a coat of hard bottom paint first, this is not a 100% seal, but darn close, and a little cheaper, especially since you only need 1 coat and the barrier coat will require a coat of either hard single season paint or a coat of ablative paint.

If you are unsure if you will continue to stay in for years to come, ablative might not be for you, it costs more up front but in the end is roughly the same. You would paint on multiple coats and they wear off with use. Hard single season paint does not wear off and builds up, requiring soda or sand blasting over time, adding to the cost that might seem cheaper at first, in the end they cost roughly the same.

A good cheaper priced ablative is aquaguard bottom paint, roughly $90 a gal, when my micron extra wears off I might switch to the aquaguard, have not decided yet, Micron Extra has been flawless, but at $240/gal, the aquaguard is very tempting and guys in my marina using it come out looking clean as I do and they are spending a lot less.

Regardless of your choice to go with ablative or hard, I would highly recommend putting a barrier coat on first, it is the only way to truely protect your investment for years to come, and then paint over it with your choice of bottom paint. Also double check that what ever paint you choose to sue is compatible with the barrier coat you pick.

 

[Hookup1]

Assuming the gelkote is in good shape (which it probably is) I wouldn't barrier coat it. De-wax it, prime and paint.

My 1997 Islander has been in the water since new and has never been barrier coated. The bottom was soda blasted two years ago, primed and then painted with Petitt Hydrocote ablative (one coat). The next year I did another cote and did the same this year. It goes on thin and works great!

I had work done on my 43' Egg Harbor a few years ago at Davis Boat Works in NC. Their attitude was that if there is no blistering on the bottom there is no water intrusion and no reason to barrier cote. They power washed the bottom, primed it and then painted it.

Although it may be "the right way" to do it in all likleyhood most of the people you talk to here don't have a barrier cote.

 

[Kurth]

Thanks for the responses.

I called around today and got varying answers.

Calling a nearby marina, the first person we talked to said to use a barrier coat, followed by hard paint and ablative. Said to drive the boat up to them so they could mark the water line while it was in the water. Then they'd lift it out and do the whole job for $800 using Interlux Micron.

Then called my local Grady White dealer. They said there's no need to put on a barrier coat unless you are going to keep the boat in fresh water. They said they'd clean the hull and give it a couple coats of Petitt Hydrocote. $30/foot ($600).

Looks like I need to do some more research!

 

[CJBROWN]

I'm a pretty devout supporter of PASCOE the suveyor. Here he talks about blisters but I can't find anything about prepping a new glass hull for bottom paint. It is fairly clear though, that a quality hull of modern high quality resins should not have a problem with blistering, hence supporting the process for a quick prep and coat with anti-fouling bottom paint. That quality is what we naturally assume our Grady's are, right?

http://www.yachtsurvey.com/blisters.htm


It would seem there's as much or more risk of blistering from inner-hull moisture as there is from water osmosis thru the gel coat. Keep the water out!!

Here's an interesting article on epoxy barrier coating from a product purveyor: http://www.epoxyproducts.com/barrier4u.html

Smith here claims to have invented barrier coat technology and explains in detail why it is necessary: http://www.smithandcompany.org/GRP/GRP.html

And another explanation for osmosis and how water permeates fiberglass gel coats when constantly immersed in water: http://www.zahnisers.com/repair/blister/blister1.htm

Another article from the DIY network on applying a barrier coat and subsequent articles on anti-fowling paints: http://www.diynetwork.com/diy/bo_enhanc ... 98,00.html

 

[Kurth]

CJBROWN - Looks like you just made my research a little easier. Thanks for the links. Now I need to get reading.

 

[lazy197]

I have been lurking for a while too and have deceided to dive in. I stripped my old 89 24 offshore with the Home Depot methyl cloride stripper 12 years ago and it was a job. Key for me was not to leave it on too long( to protect the gel), just long enough to soften paint. about 15 or 20 minutes (do small sections) if I remember right. Then wipe it down with thinner, came out great.

I sold the 24 2 years later and just last year purchased a 1994 208 w/ 2001 175 Johnson. It needs to be stripped too. I looked at soda blasting and from what I can tell it is going to open the Gel just not as bad as sand blasting. I would still have to barrier coat.

I do not think I need to barrier coat if I strip, it does not open the gel (but has the potenial to soften it temporarly). This year I am out of time so I am slapping a coat of abative over the the 14 years of chipping hard paint and will probably strip next year then one coat of hard paint and 2 of abative.

Why barrier coat if the gel is fine and of high quality. Seems like over kill?

 

[uncljohn]

Gelcoat is not an 'impermeable membrane'. It will eventually absorb water. No matter how shiny or waxy it is. To create an impermeable membrane, you need to apply a barrier coat. At least 4 coats of it.

 

[BobP]

I don't recall a Grady reported with blisters, not that it has not occurred, just don't recall reading of it -

 

[CJBROWN]

I don't recall a Grady reported with blisters, not that it has not occurred, just don't recall reading of it -

Yeah, they do a pretty good job of coating the inside too. And their glass layup is some of the best I have ever seen. When you can look in the bildge and see woven roving strands you see a different kind of boat. They look like those old deep-water sailboats I used to inspect.

The biggest issue with blisters is water wicking thru glass fibers and finding pockets.

If my boat was a couple of hundred grand or more I'd be taking a more cautious approach. But for a 20' runnabout that's going to sit in the water part time I don't think I would bother. Down the road, if it showed up with a blister or two then I would have it blasted and coated.

From the articles I found there are certainly some strong proponents for barrier coats. Again, I think I would go that route if the bottom showed that it needed it.

And I thought there were some recent developments in gel coat material, vinyl esters or something? That was supposed to cure the blistering problem, and be more impervious to water osmosis?

Just my 2-cents.

 

[BobP]

I thought the quality of gelcoat used - was a factor.

 

[seasick]

Read this presentation. It is an excelent discussion of blistering and the part that gel coat does and does not play in the formation of blisters.

http://www.compositesaustralia.com.au/p ... ection.pdf

 

[CJBROWN]

That's a good explanation on the factors involved.

Most of you have seen this article on Grady boats. If you look on page 5 they talk about hull construction and that they don't use vinylester resin, but what they do to ensure no blisters:
http://www.gradywhite.com/magazine_revi ... y.2006.pdf

In digging around for information on gel coats and Grady White, I found an application to the EPA for vinylester resin use, they are only allowed 5% by volume in their plant. Apparently this is some poison stuff, so that may be a factor in seeing widespread use in manufacturing. In another article the NMMA (national marine manufacturers assoc) was asking the EPA for a seperate ruling or consideration for vinylester resin use in boat construction.

Going back to the OP, I would slap some good bottom paint on 'er and splash it. :wink:

 

[Hookup1]

I watched the Canyon Club do a 56' Ocean last year for a friend of mine. They blasted the bottom with volcanic ash (no I don't know which volcano it came from), applied four coats of epoxey barrier coat, put a different color coat on (not sure what it was) and then sanded the different color off the entire bottom to get it smooth as gel cote (color showed high/low spots). Primed and applied Micron - base color plus 2 color coats. Thats nine coats of paint!

Its much easier on a 20 footer but the process is the same. It gets expensive if done right.

There is no question that a barrier coat would protect against water intrusion and blistering but I would just prime and paint. If its not broke don't fix it!

 

[Bob's Cay]

I guess I am one of the few that has a Grady that did have blisters, and pretty bad at that. It was about 5 years ago and so the boat was about 15 years old. The gel coat was planed off the bottom and the boat was stored inside for about 4 months to assure it was dry. They would check with a moisture meter. Actually draped plastic off the hull for a while and ran heaters to dry it out. They did install a barrier coat and Interlux Micron. That paint lasted several years. The boat had been stored for about 2 years in freshwater without bottom paint. I was mistaken to think if I keep it scrubbed it didn't need paint. Several people told me that part of my problem was a reaction between my boat, the steel supports of the dock, and the pontoon boat docked next to it. Some type of electrolysis or something.

Phase 2- I decided when it was time to repaint to do it myself. I went back with Interlux Micron (Dark Blue). As I am prone to do I followed and "exceeded" the directions for the recoat. Turns out I should have just followed directions. I actually hand sanded and wiped with solvent much more than needed. Should have just power washed. After a few years tha paint started to come off in flakes.

Phase 3 - Last year I decided to let a yard do the repaint. The Interlux paint was flaking off (2 years) and was very faded. When they pulled the boat we found about a half dozen small blisters. It was decided to sand the bottom down again, repair the small blisters and install a new barrier coat. This time on some advice I went with a Petit system including the Vivid bottom paint (black). It looked great when finished. Very smooth and much "harder" than the Interlux. The black had a low gloss to it.

Well yesterday I pulled the boat from the water for the first time in a year. The bottom looked brand new after a quick hose down. The black still has a low gloss. I am very impressed with the Vivid paint.