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Interprotect Barrier Coat Questions

9K views 12 replies 7 participants last post by  deniseO30 
#1 ·
Greetings,

I'm seeing light at the end of the tunnel on my year-and-a-half long refit project, (CS27 ~ Ravat) and am finally barrier coating the hull. I'm going to use Interprotect 2000e, and complete that with VC-17 anti-fowling since that's what everyone else uses around here.

It's looking like temps will be in the low 60s here with pretty average humidity levels. My boat is a shoal draft CS27.

I know about using alternating colors, the correct foam rollers, thumb print curing check, and the boat's bottom is well prepped according to recommendations. I am assuming that I will need one roller and one brush per coat. That being said, here are my questions:

1. Are there any guidelines regarding how much I should mix at a time? Should I mix up the entire batch at once? Should I go half and half? Having never done this, I'm not sure how fast it will kick over or how fast it will apply.

2. Is it better to apply all the coats and then hit it with a quick sander to smooth things out, or to do some form of a roll and tip to keep it smooth as I go? Or am I just wasting time picking nits? I'm not planning to race (well, not SERIOUSLY anyway!). Just cruising. I do want the boat to look good though - after all this work I want it to look like it was done well.

3. At the tape line is it normal to just leave that area standing proud, or do people carefully hand sand it down? I'm guessing it's just left as-is, but hard to tell fromt he boats around me since they have a few layers of bottom paint over them by now obscuring it.

4. Did I miss anything? (Loaded question!)

Thanks in advance,
Chris
 
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#2 ·
I wouldn't mix more than it takes to do a coat at a time or you'll find it setting up in your bucket. You want build (minimum 10 mils) which doesn't lend itself to appearance. The fish don't care what the bottom paint looks like and sanding ablative (if that's what you're using) is an oxymoron. If going with Baltoplate or VC-17 then yes, burnish the paint after you are done. Interprotect is an epoxy and does not sand well. That's not what it's designed for.
 
#3 ·
I just did this with my 39 footer, and bulb keel. I found one gallon of the 2000e covered the boat bow to stern, and then did 5 coats over a few weeks. The time between coats is up to a few weeks, so just reapplying is fine. No sanding needed. The transition from the 2000e to the first coat of antifouling is the one that matters as to a short time. The yard where I did it told me, finish the coat of 2000e, go to lunch and then in about 3 hours (65 degree day), it was dry and I put on the antifouling.
Then you have days again where no sanding is needed before the next coat of bottom pain.
Sounds like you have done your homework, so it should be something to behold once it is done.
 
#4 · (Edited)
I would opt for cooler weather.. the stuff kicks off quick! typical of epoxies if you leave it mixed and in a can it will kick even faster. When we coated strip canoes we always used shallow pans for the stuff. (clear epoxy) When We did the barrier coat on my boat,(2000E) it went well but I expected it to kick faster then the label would lead you to believe. I've had bad luck with foam rollers too.
 
#8 ·
I don't have much of an option for looking for cooler weather... Spring has sprung. If I wait, it will most likely only get warmer.

What type of bad luck did you have with foam rollers? It was my understanding that solvent resistant rollers are the right tool for the job. Is there more to it?
 
#5 ·
Chris,
The CS27 is a sweet boat, and its great to someone giving one a second life. I'm sure you will find years of satisfaction and pleasure in payback for all the pain and $$$ you are investing - great job.

As you have been given good advice above, I'll offer a sailing caution based on your blog's picture...always remove any slack from your reefing lines...you wouldn't want a loop to catch a head during a gybe, especially after all this work...
 
#9 ·
Not to get too far off topic, or intentionally embarass myself, but that was my second time sailing the boat, and I barely knew what reefing was at that time :eek:

To be honest, I am not sure how to reef this boat's main yet. The PO did some very unique customizations... Things which were... How shall I say it? Creative! So the original reefing system is probably not rigged properly. That's going to be one of the summer projects... One of MANY!
 
#6 ·
On VC-17, I've not applied it myself, but have observed the application to my boat several times. A solvent resistant roller was used. It seems quite thin, and only a small amount was mixed at a time. No thinner was used. Six, less than one quart cans were used on our 36' boat for more than one coat, which I think is somewhat more than usual. It dries quicky so there was no wait between coats. Extra coats were applied to leading edges.

The manufactures Web site has instructions.
 
#7 ·
If you apply with a foam roller there should be no real need to sand or roll & tip. For the "hot coating" you want thumbprint dry. This means you can leave a thumbprint but none comes off on your thumb.

For our boat this was roughly a 15-20 minute window at about 72 degrees so one guy was rolling the last coat of 2000e while the next guy followed about 20 minutes behind. The "hot coat" layer is the most important one as it chemically bonds the first paint layer to the epoxy so you don't get peeling paint in a few seasons.
 
#10 ·
If you apply with a foam roller there should be no real need to sand or roll & tip. For the "hot coating" you want thumbprint dry. This means you can leave a thumbprint but none comes off on your thumb.

For our boat this was roughly a 15-20 minute window at about 72 degrees so one guy was rolling the last coat of 2000e while the next guy followed about 20 minutes behind. The "hot coat" layer is the most important one as it chemically bonds the first paint layer to the epoxy so you don't get peeling paint in a few seasons.
According to the Interprotect Product sheet when overcoating with VC-17m the Interprotect layers are supposed to dry for 24-36 hours, then be sanded with 180-220 grit paper.

So, it looks like the thumb prints are more for timing the Interprotect layers than tying in with my anti-fowling. This process only applies to the VC-17m or VC-17m Extra though. All other anti-fowling paints must be applied in the overcoating window.

Lotsa details to manage with these boat projects!
 
#12 ·
Success!

Just wanted to check in and thank everyone for the moral support leading up to the project. I got two coats applied today, and she looks like a new boat. It's nothing short of amazing.

I ended up using a solvent resistant mohair brush in a nap slightly finer than what Interlux called for. Why? Because it's what the chandlery had in stock and I didn't want to blow time driving elsewhere. The finish is certainly not gelcoat-smooth, but it's very, very nice compared to what I started with. I have no complaints.

It was a little tricky figuring out how thick to roll it on. I get the impression that Interlux wants it rolled on fairly heavy based on the number of coats they recommend and how far each batch went. Takes quite a bit of concentration to avoid sags at that level, but it is very do-able. My second coat was a day and night difference from the first. A nice quality of IP2k is that its thickness hides goofs very efficiently on subsequent coats.

There were ZERO issues with quick curing. I mixed up 50% of the product per batch and let it sit for the recommended 15-20 minutes to evacutate air bubbles. I'd occasionally see a little skim on the surface of the bucket's contents, but 10-15 seconds of swizzling dissolved that back into the soup.

One gallon of IP2k covered about 1-1/3 of my hull, so I think I'm going to end up over Interlux's recommended thickness. No harm done there.

Here she is at coat #2 where I left her this evening...




Tomorrow morning it's back out to the yard to finish up coats 3 & 4. If I'm lucky I may even get the new bow hatch installed while coat 3 dries. Whew!
 
#13 ·
Last year I helped a friend do the coat on his Erricson 27. the old gel coat was all spider cracked I mean the whole bottom too.. He completely stripped all the old paint, and did like 6 thick coats of 2000E. Not a single crack has telegraphed through the barrier coat a year later. So it's not only a barrier coat it's also a new skin.
 
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