The Fine Details of Epoxy Use

[bludden]

In a few weeks I fly to my new yacht in the Caribbean to get her ready for cruising and the first job is the application of an epoxy barrier coat. I'll probably use West System products but am having difficulty finding the fine details of barrier coating. I envisage my wife mixing and cleaning and me furiously rolling down one side of our 46 foot cat and hopefully having time to do the other side of the first hull before the first applied resin reaches the "recoat" phase. My questions are:
1. Disposable foam roller covers: the West literature recommends mixing in small batches, but can I keep using the same roller cover (and paint tray) just pouring fresh mixture in every 10 minutes or so? I'd need a hundred covers otherwise!
2. Has anyone experience with West System epoxy in the Caribbean and if so what sort of pot life and time to recoating did you experience? I'm leaning towards the 207 or 206 hardener but would appreciate comments from those who have used them.
3. I plan to apply 3 coats of epoxy, then anti-fouling; do I have to re-tape the waterline each coat?
4. Has anyone used the "barrier coat additive 422" ? It'd want to be good for cost!
Normally one could just "suck it and see" with hardeners etc. but it appears I have to pre-order all the materials or wait weeks and weeks for the next shipments to arrive. Cheers

[minaret]

1. Only to some degree, depends on hardener and temp. Use cheap disposable plastic trays and buy roller covers by the package.

2. Not in the Carribbean but plenty in hot weather. With just two people I'd be tempted to use Slow or even Tropical depending on temp.

3.Plan on lots of sanding before bottom paint. When we used to do bottoms with WEST we always slicked the bottom with a final coat of WEST and 407 because it sands out so much quicker than straight resin does. It will not go on very nicely no matter what you do. Re-taping the waterline a couple of times is the least of your problems.

4. Barrier coat additive is pretty useless, I've even had a WEST rep tell me so. They used to reccomend the carbon fire-resistant additive as well for barrier coating, I've tried them all and it's all about the same, just so-so for a barrier coat.


Why are you using WEST instead of Interlux 2000/2001? 2000 is a much better product for barrier coating, and much easier and faster to use. No sanding! And it actually works and lasts. We are one of the few yards around who warranty our bottom jobs for 10 yrs.

[svtrio]

I have applied West Epoxy several times as a barrier coating and would not recommend it because doing the underbody of a large boat in a hot climate requires mixing too many small batches of prepared epoxy (extra slow 209 hardener) and moving very fast to get the job done. Moreover, you will likely be sanding between coats because the epoxy is likely to go off before you can apply the next coat; after the epoxy has set, it MUST BE WASHED before sanding and applying the next coat. I gather that you haven't worked with epoxy very much, and I'm offering the best advice based on my experience, without too many details. West Epoxy is, however, my choice of product for repairs and construction of fiberglass boats.

Interlux's Interprotect 3000 will be dramatically more user friendly and applying it in high ambient temperatures is easily doable. It is a thicker mixture and overcoating can be faster than the Interlux 2000E product (slightly cheaper). Three-four coats will meet the recommended minimum for protection. Sanding between coats won't be necessary, so you can get the job done fairly quickly using 3/8" nap rollers, preferably those recommended for epoxy. Mixing is simple and merely requires mixing two components in a bucket. The material goes on well, even on vertical surfaces and overhangs. I've applied this product several times and it is my product of choice for barrier coating.

Go to the Interlux website to get the full skinny and give a telephone call to their tech support. They are helpful and can give you good answers to your questions about their product. (West System tech support is very good too.) <http://www.yachtpaint.com/usa/pro/products/Search.aspx?BannerName=interprotect>

Whatever you decide, check your destination to confirm the product of choice is available.

Good luck.

Roger

[HopCar]

I vote for the Interlux products as well. WEST makes great products but Interprotect is a better barrier coating. One good thing about epoxy is that it can usually ship as a non-hazardous material. Shipping bottom paint is another story.

[SabreKai]

I'll concur. Mixing up batches of West system in hotter temperatures is no fun at all. Better to go with the Interlux products.

[Boracay]

Once epoxy gets out of control it gets real messy, real fast. It needs accurate mixing, drips, runs, and sticks everywhere but where it should. Accurate thickness will be difficult to achieve. Leave a pot too long and it becomes unusable and can even catch fire.

At a minimum the hull will need to be taken back to bare gelcoat and keyed. I'm assuming that you want to do this because there is some "osmosis". If so the blisters will need to be "removed" the underlying fibreglass dried and the resultant holes filled. I seem to recall some boats taking many months to dry out before the holes can be filled and the barrier applied. This not a simple job.

All of the above needs to be done in to tropical heat and overhand. I hate to think how many square metres of hull there are in a 46' cat.

I've heard reports that some professional barrier coat jobs are of indifferent quality while others are superb with no further problems occurring. If the professionals have trouble getting it right than what sort of result do you expect?

While my wife has been more than happy to assist with antifouling I've found she is much happier doing almost anything else...

I would seriously question the necessity to do this as you pick up a new to you boat. If the need is so urgent surely you would not be buying the boat. The logistics and effort involved are mind bending.

If there are a few blisters why not leave them. Get the local workers to splash on a few coats of Primocon or whatever they use as a sealing primer there, then antifoul. Use your time and energy to check that they have all needed materials and put on the required thickness. Make sure they know there's a slab of beer in it for them when they finish. Also check that you have the required ingredients for your favorite cocktail when the boat goes back in the water.

Ask round as you have time, find who does the best barrier coat, and next time you have to come out of the water go there.

Unless you want to be part of the local folklore for the next generation.

[bludden]

On the contrary my FP Bahia's hull is in perfect shape, the surveyor and I went over every inch and found not the slightest defect. Due to the need to come home to Australia to pack up our lives, our boat was going to be on the hard for 6 to 7 months and I thought I'd take the oportunity of drying the hull out and barrier coating her while the opportunity existed. The yard had their workers scrape and then sand the hulls back to the gelcoat at what I think was a very reasonable price and now I'm up for $600 to $900 in materials and a week or two of hard yakka to make my boat much more resistant to the pox. A bargain I reckon. I've started to look at the interprotect 2000 and am impressed. I presume the advantage is the mica chips but more importantly the ability to delay recoating up to two weeks between coats!! Why doesn't Interprotect blush like everyone else's epoxies? It's been manufactured for so long we'd already have heard if their claims are bogus. I still think I'd better order dozens of roller covers though. Thanks so much for all your help. What a resource this forum is. Without it I hate to think how much strife I would have got myself in trying to use "normal" epoxy. The wife almost surely would have been off home before we started!

[Duke 48]

Another vote for the Interlux. Though I have never used Interlux, I have used the West Systems barrier coating. It was a real challenge even with cooler temperatures.
Duke

[Blue Stocking]

14 years ago used Interlux sealer and barrier coat, with hard epoxy based bottom coat applied, just as last barrier coat "kicked". No blisters to this day.

[imagine2frolic]

I have used West on numerous projects over 9 years. The biggest being a new cockpit floor. It was winter in Northern Florida. It would"ve been a real mess in summer. I would imagine a big project like that needs to be in a climated controlled situation. I know that's how the boat was built........i2f

[Matt sachs]

Why does West it have to be washed prior to sanding? I'm not being a smart arse, just curious?

[captain58sailin]

It generates a film that has to be washed off before applying the next coat, Systems 3 has the same protocol. A local boat builder I consulted with extensively advised that I use a sudsy ammonia mixture to help cut the film.

[Matt sachs]

Originally Posted by captain58sailin

It generates a film that has to be washed off before applying the next coat, Systems 3 has the same protocol. A local boat builder I consulted with extensively advised that I use a sudsy ammonia mixture to help cut the film.

......even if its sanded 5 minutes prior to the next coat?

[Matt sachs]

I'm asking to see if I have screwed up to badly....

[emeraldsea]

My understanding was that you could re-coat with-in 12 hours without washing or sanding, it would still form a chemical bond. I also though washing with just water was sufficient. I'd be interested in knowing a better cleaning mix,...like dilute some windex or what do you do?