Wet Slip Advice?

[Lorne Colish]

I bought my 2002 Mac used with a new clear epoxy bottom on it, and so I thought Id be OK with Aurora Bottom wax with antifouling in it.I wasn't,It blistered.My boat sits in the water all summer at Lake Of The Woods. When I called the previous owner,I found out that he had blistering the first season and had the bottom epoxied at Macgregors expense.Unfortunately, It was the wrong stuff according to the Interlux rep I spoke to.So I sanded ,painted and antifouled it myself as prescribed by Interlux.When it came out of the water last season,it looked fine.
I had a 1988 26D that blistered as well and then was fine for years after I did the Interprotect barrier coat. So if it is rare on Macgregors,I've been very unlucky.

[Rick Mathews]

Sounds like you guys have discussed this issue pretty thoroughly, but for what it's worth I thought I'd throw in the advice Blue Water Yachts in Seattle gave to us when we purchased our 2002 X, and what our experience has been since then.

Blue Water says that if the boat will be kept in the water year-round, then bottom paint is necessary. Otherwise they advise not painting the bottom if it can possibly be avoided, because you lose about a knot of speed (and of course you have to repaint regularly). If the ballast is kept in, they recommend putting a cup of bleach in the ballast tank to prevent growths from accumulating.

We keep Pilgrim in the relatively cold fresh water of the Columbia River six months out of the year, and we nearly always empty the ballast between outings. We have done alright so far with just wax. We purchased a "Dri-diver", and have to use it every week or two or the algae tends to take over. We don't have to worry about barnacles, of course. We tried "Easy-On Bottom Coating" last season that is a "stay-soft" wax that's supposed to help keep the algae off, but I don't really recommend it because it wasn't very effective. This coming season we plan to go back to just two coats of regular wax--specifically West Marine's Premium Polymer stuff.

[rick(Snow Goose)]

Hi guys
I discovered blisters on the bottom of my 2001X this fall when getting her ready to put away for the winter so I am very interested in this thread. The blisters I found were in several small clusters approx. 2'X2' and they were round and tiny, 1/8" diameter.
My boat is in salt water, ballast in, for about 10 weeks each summer, and 3 months in florida last winter, with 2 coats of teflon wax on the factory gel coat each spring.
Should I sand the blisters out before putting on an epoxy barrier coat and do I need to apply bottom paint after? Does anyone have a link for this? Will be follow ing this thread with interest.

[Jeff Ritsema]

Hi guys
I discovered blisters on the bottom of my 2001X this fall when getting her ready to put away for the winter so I am very interested in this thread. The blisters I found were in several small clusters approx. 2'X2' and they were round and tiny, 1/8" diameter.
My boat is in salt water, ballast in, for about 10 weeks each summer, and 3 months in florida last winter, with 2 coats of teflon wax on the factory gel coat each spring.
Should I sand the blisters out before putting on an epoxy barrier coat and do I need to apply bottom paint after? Does anyone have a link for this? Will be follow ing this thread with interest.

Rick, From my own experience of blister repair, there are several steps that have to be considered and although this was done be a biat yard, the process is the same in concept. 1) the blisters have to be removed to the depth that they have impregnated the FG, and this could be deeply into the mat. When done on an entire hull, the gell is stripped by professional "strippers- now wait guys" who have dedicated tools that take off an even amount of FG to a cetain mil thickness 2) this is followed bay a "drying time" which may include the use of electrical radiant heaters that bake the moisture out of the glass- this can take weeks to assure drying 3) this is followed by the application of an epoxy surface (interlux has a process for this), followed by fairing and sanding, followed by barrier coats and bottom antifouling. Lot of work and expense if done properly. Of course, this all is relative to the amount and depth of the blistering and infiltration of the water into the glass.
I would have a yard that does hull repair take a look at the area of blister and maybe get a second opinion before either having it done for you or before you proceed to repair it yourself. This isn't something you want to do twice. Hope this helps, and anyone with experience that differs from mine feel free to climb in on this.
Jeff.

[Lorne Colish]

The blisters on both my Macs were very small and not noticable unless you're up close.They were sanded off easily with 80 grit paper and left over winter to dry out.After one more fast sanding in the spring,I applied 4 barrier coats,followed by two coats of antifouling as per Interlux directions.
On my previous Mac,I only did 2 coats in the spring and no antifouling,and to the best of my knowledge is still doing fine after 14 years. I'm not recommending this easier,cheaper approach,but it interesting how well it worked.

[Dominic]

Had experience of this on another type of boat (about 12 years old) and could not afford a dealer remedy (over 4000) which works out at nearly $8000 at today's rates! This would have involved planing the whole gel coat below the waterline, drying the hull, repairing the damage, rebuilding the gel coat and so on... However, the fibreglass guy was most helpful and suggested an alternative DIY route. I understood blisters occur due to pressure built up in the hull and can ultimately lead to delamination of the hull. In really bad cases, you can push the fiberglass with your fingers an feel the hull 'give' a bit and if you scrape away the tops of the blisters there may be a runny liquid with a strong vinegar smell and this is the chemical causing the pressure. In my case the blisters were no too bad but had to be dealt with properly.

I cleaned the blisters out leaving a concave pocket, filled this pocket with an epoxy filler (e.g West system) and sanded the surface flush. Hitachi make a brilliant chisel type tool which is great for scraping the blisters and getting rid of old antifoul. All traces of anifoul are removed and the hull degreased - I used a rag soaked with liberal dose of white spirit, a light sanding to provide a key, followed by another cleaning with methalated spirit. The epoxy is a two part system, paint on the adhesive and then paint on the hardener, the subsequent reaction leaves a hard plastic surface which resists osmosis, then apply an antifoul coating. This was done about 5/6 years ago and the boat is still blister free.

The fibreglass guy told me coloured gel coats are more prone to osmosis as are boats kept in fresh water but the temperature of the water plays a big part in this, and that fibreglass is not waterproof nor is the epoxy coat, it is just that the epoxy resists moisture penetration better than the gel coat. He aso recommended, if possible, pulling the boat out of the water for 3/4 months of the year to let the laminate dry out. I have to say though, I have never seen any trailer sailer with osmosis.

[Moe]

Okay... I'm convinced... the epoxy barrier paint is worth it!

--
Moe

[Jeff Ritsema]

Okay... I'm convinced... the epoxy barrier paint is worth it!

--
Moe

Moe, I would agree, providing you intend to keep the boat in the water for several months. I would still consider not doing it if trailer storing the boat. You lose speed with bottom coatings, and once applied, it's a permanent committment.

[Moe]

We plan to have it in a freshwater slip 6-8 months this year. Will use VC-17 bottom paint.

--
Moe

[Moe]

Let's carry this one step further... if I were going to install a keelguard, should it be installed after the epoxy barrier coat, but before the antifouling paint?

--
Moe

[Terry]

Yep, I'm still looking for a way around using epoxy paint, so I found a couple other new fangled products for evaluation. Check these ones out as alternatives to painting (since Poliglass & NewGlass are no-goes).
http://www.marineglide.com/faqs.htm
http://www.trustmymechanic.com/best_boat_wax.html
This next one is more of a wax but is teflon based.
http://www.properautocare.com/prmapowite.html
Even if these products give me 2- 3 months protection, I don't mind pulling my boat out for a day ( a hot one) to let the hull dry out. It is only 10-15 dollars in & out included to let the hull dry for a day. Actually I'm willing to haul out monthly to wash the slime off the bottom and at max I will only moor 6 months of the year due to seasons in this northern climate. The most realistic scenario is 3-4 months mooring.
So do I still have to epoxy paint?

[Duane Dunn, Allegro]

I assume you are going to keep it in local BC salt water. We used a wax, Bottom Wax, on our boat during our 3-1/2 week cruise in the inside passage last summer. This is a wax much like all the ones you linked to. They make antifouling claims , but I doubt any of them would really have any effect on reducing osmosis. The 'Safe Boat Skin' does look interesting however.

After the 3+ weeks straight in the water there was visible weed growth along the water line and it was worst at the transom where my wife didn't apply the wax. It washed off fairly easily where the wax was but there is still residue from it along the transom that wasn't waxed. We were also moving most of the time, we covered 502 nautical miles, which reduces the ability of stuff to grow.

Weed growth and scum isn't the biggest worry. It's the other critters. We sold our previous boat to my sister. The first summer they had it they kept it anchored out in front of their property off Hartstien Island in the south Puget Sound. It was in the water 2 months, and during that time the area had a barnacle set. Because the bottom was not protected by bottom paint (I warned her), when they pulled it the entire bottom was covered in 1/4" barnacles. Quite a clean up job. Barnacles don't set every day, they are occasional events that depend on the water conditions. It just depends what happens in the area you keep it. Take a look around at other boats, pilings, rocks, and you can get a pretty good idea of what your boat will encounter. Look at all the other boats bottoms in the marina. If every one of them has bottom paint you might want to follow their lead.

I wouldn't store a new Mac in salt water without bottom paint for even a month. I'd be more concerned about marine growth than osmosis, but I'd also have an epoxy barrier under the bottom paint. Why risk a brand new $30k boat.

If you think you are going to dry any osmosis issues out in a single hot day you are kidding yourself. On boats with osmosis problems they open the blisters and strip the gel coat then store them in heated enclosures for months to dry the laminate.

[Duane Dunn, Allegro]

Yikes, check out the price of 'Safe Boat Skin'. For a 30' boat they say you need two bottles at $99 each.

[ESPERANZA]

OK, so what paint would you recomend for a boat in a fresh water slip six months out of the year? Is there a paint out there that doesn't leave a Rhino Liner finish when it dries?

[Moe]

Here's what Power Sailing Center does:

Protect your investment by having your hull protected from blistering. We use five coats of VC-TAR barrier epoxy, which stops moisture from penetrating the gel-coat. The self-leveling characteristics provide a super-smooth surface for subsequent application of anti foiling paint. The VC-TAR is over coated with VC-17. This thin film, Teflon-based coating dries to a super-smooth finish thats ideal for racing sailboats and high-speed powerboats. Hard enough to stand up to trailering. Contains copper powder to provide antifouling protection in fresh water and low-fouling saltwater areas. Available in blue/red/gray

On a new Mac 26 it costs $1,295. For a boat that's been in the water (and/or trailered as much as ours, I'm sure) there's additional cost for cleaning.

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Moe