Anyone using Interlux VC-17m?

[Noah]

Everyone around here thinks that it is a great bottom paint. I had terrible luck with Interlux Fiberglass bottom coat, and I want to try something new.

My hull is almost down to bare wood, but there are still a few spots with a bit of the fiberglass bottom coat left.

I'm wondering what the best way to prepare the boat for some ablative paint. What is a good primer for this sort of thing? Especially for using with the VC-17m? I have heard that the VC-Tar is terrible sh*t, and I should stay away from it at all costs.

Noah

[Todd Bradshaw]

Two things worth knowing about VC-17 are that it has a very low copper content compared to most bottom paints, which may or may not keep stuff off of your hull, and it has a very strong solvent in it that might crinkle the undercoat if it's not right for the job. I have been in areas where it offered decent protection and then moved, put the same boat in new waters and had the bottom look like shag carpet by mid June. The stuff is water-thin (don't tilt the roller sideways as it will run out on the ground) dries almost instantly and is quite smooth and slick when dry, but as I remember, it's only 17%-18% copper. I finally switched to "Hydrocoat", a water-based ablative with Teflon and though not as smooth, it's easy to apply, cleans-up with water and protects hulls much better on our lakes.
VC Tar is mostly advertised as a blister-preventing barrier coat for fiberglass. People that I know who have used it say that it takes forever to dry, and even then isn't really dry. I have yet to meet anyone who seems thrilled with the product.

[Ian G Wright]

,,,,,,,,,,,I'm thrilled with VC Epoxy tar. smile.gif
Patience was coated with it (underwater) from new, three coats. Seems fine to me,,,,,,,,,,
Not sure about their anti-fouling though.

IanW.

[Noah]

Hmmm, as always two different answers. It seems that people are very happy with the VC-17m as far as keeping growth down to a minimum on this lake. I have also been looking at the boats, and none with the VC have any Zebra mussels, so I think it will be good.

Now as to a primer...
Ian, you really like the VC-Tar? Everyone that I have talked to says it is the worst stuff known to man, and never put it on a boat...But I'm willing to listen.

What else would people use as an undercoat? That is the real question right now.

Thanks,

Noah

[Conard]

Noah,
For what it's worth, we put Pettit unepoxy on our Herreshoff. It was in the water at Point Bay from mid-June to late October, and nothing stuck to it.

[Todd Bradshaw]

We had Unepoxy on our trimaran before we switched to the VC and then to the Hydrocoat. As David said, it's quite good at repelling growth. The problem that I found was that once the copper leeches out, it leaves a pretty thick, very hard layer of paint. I don't know how much actual "epoxy" it contains, but it is almost as hard to sand as resin. After three or four seasonal applications, there was enough dead bottom paint left that I didn't want to add more and make the build-up any thicker or lumpier. Removal was a very nasty mix of chemical stripping and sanding, which I swore I would never do again. Since VC is so thin, I figured that I could let it build-up for many years without a noticeable change in thickness. Then we moved and our new mooring was in about three feet of slow-moving water on kind of a mud-flat. My best guess was that the area was just too fertile for the VC to stop the growth and it quickly failed.

The next season began with sanding all three hulls - again - to remove the VC and applying the Hydrocoat. At that point, there was no way I was going to put anything on the bottoms that wouldn't eventually remove itself and self-limit the season-to-season build-up. Hydrocoat seemed to have antifouling properties similar to Unepoxy (we never needed to use anything but a hose and a sponge to get the hull clean at the end of a season) and goes on like latex on a bathroom wall with minimal fumes and hassle. Standard practice was to inspect the hull each spring, throw on a quick coat and touch-up any worn areas like the stem and along the waterline as needed, with another layer. Hydrocoat hasn't gotten much press. It was originally packaged with a Woolsey label and now is sold by Pettit, but seems to be the same stuff.

Anyway, I'm sure there are plenty of other good choices for bottom paint out there, but that's what I found. It was the first time that I had used anything water-based on a boat and I was pretty leery about it at first, but after grilling the Woolsey tech guys and actually trying it I was quite happy with the results.

[Noah]

One of the big problems with my boat is that the wood moves so much. As I have noted before, the planking changes in size dramtically with moisture. IE I get gaps as large as 1/2" over the winter. I like the sound of the Unepoxy, but I worry about it being so hard. I feel that it might just crack off the boat as it swells and shrinks. This may have been what happened with the Fiberglass Bottom coat that I used last year.
The plus is that Unepxoy is only $50 per gallon, which is way less than half of the other paints. For two coats I will need two gallons of the stuff...Expensive when we are talking about VC-17m...

I will look at the Hydrocoat. BTW, what do you use for a primer on it?

Noah

[CptnDon]

Just read the label on the can to see what primer to use. Always use products from the same manufacturer.If you decide to use ablative paint,use different colors in each coat. That way you can see how much "wear" there is.

[Todd Bradshaw]

Noah,
Our "test boat" was one of the smaller Farrier fiberglass trimarans which I barrier coated with six coats of WEST epoxy with their aluminum powder, barrier coat stuff mixed in. I'm sure the same formula would be a disaster on your hull. I did find partial cans of all three types in the garage and could read around the drips to see what they suggested for bare wood:

Unepoxy Plus - Sand bare wood to 80 grit, wash the hull with their #12120 Brushing thinner, apply the first coat of Unepoxy thinned 25% with #12120, dry overnight, sand lightly and apply two more coats, full strength.

VC-17m - Sand bare wood to 80-100 grit, wipe hull with V-170 General Thinner and apply three coats of VC-17. This stuff dries so fast that I've seen people at the ramp with rollers, painting the area that was blocked by the trailer bunks as the crane is lifting the hull off of the trailer and getting ready to drop it in the water.

Hydrocoat - Sand bare wood to 80 grit, wipe it down with a clean damp rag, apply one coat of Hydrocoat thinned 10% with fresh water, let it dry overnight and then apply two more coats, full strength, burnish as desired (we never did, it burnishes itself as you sail).

They all also claim that they will go on over old paint in good condition (sanded, to give it some tooth). With the VC, I'd test it first. You notice when you first open a can that it is nearly all solvent (you actually mix-in the copper powder from a seperate pouch yourself) and it's pretty powerful smelling stuff.

Sounds like you don't need to prime with anything but maybe some of the other folks have ideas or experience to the contrary. I have always wondered why bottom paint seems so stable underwater and by comparison, premium, one-part enamels like Easypoxy and Brightside are usually toast within a month of immersion. Where is that Chemist guy when you need him???

[Allen Foote]

Using the VC "Disappearing paint" on your boat is a waste of $. Its great for racing (fiberglass) sailboats that are hauled annually and saves the chore of burnishing a hard modified epoxy paint finish. You would be better off with a different paint. Since you are talking ablatives....use a high quality such as CSC Micron or ACP 50. With Ablatives...you get what you pay for. The low end ablatives are a single season paint regardless of whats on the label....same as a cheap modified epoxy....and they add up, after 4 years you've got layers of dead paint soaked with water weighing down your hull. The beauty of ablatives is that once a season you jump in the water and scrub the growth off....and it comes off easy with ablatives....comes off in a cloud of paint. If you are in salt water then add a biocide that targets barnicles as ablatives have a low copper content. Sold for $20.....follow directions 100% for decent results. Now, if you'd rather have a hard finish (low drag) and high copper then try Interlux Ultra with Teflon for "cleaning ease"...its a modified epoxy so the other BottomKote's gotta come off first.