Bottom painting, where do I start?

higgs · Nov 6, 2011

Re: Bottom painting, where do I start..?

You may want - correct that - need to strip the old paint down to gel coat.

Not sure where Eagle River is (WI?) but those of us in northern fresh water lakes seem to like VC17. Once on, yearly maintenance is a piece of cake.

Are you leaving the boat in the water for extended periods of time? If not, you don't need bottom paint.

Ross · Nov 6, 2011

Re: Bottom painting, where do I start..?

If the boat doesn't spend a week or more in the water at any time. You need only scrub the botton when you haul it home. Many of the boats used on the upper Chesapeake Bay( partly fresh water partly brackish) that are launched and pulled each day are simply kept scrubbed clean.

Merlin Clark · Nov 6, 2011

Re: Bottom painting, where do I start..?

I used "Dads" paint stripper the one time I completely stripped a boat and still had to do a bunch of sanding. There is a system called something like "peel and strip" that I intend to use the next time I haul this boat.
As I understand it, you apply the stripper and then a cloth over the stripper and after the required soak time, peel the cloth and the paint away. Sounds easy!

mcrow33 · Nov 6, 2011

Re: Bottom painting, where do I start..?

I used a paint scrapper to clean mine up. It was a lot of work, about 4 day to do my Endeavour 32. I then lightly sanded with 80 grit and cover it with 2 coats of VC-17. I hauled after 4 months in Lake Champlain. Bottom was clean. If you are keeping your boat on a trailer and not in the water. I won't worry about bottom paint. It only used to keep stuff from growing on your hull. Most bottom paint needs to be kept in the water for them to keep working.

Ed Schenck · Nov 6, 2011

Re: Bottom painting, where do I start..?

Once I took the bottom down to bare gelcoat using paint scrapers and sandpaper, long tough job. Then I applied five coats of barrier-coat, Interlux 2000E. This year I had my 37-footer soda blasted, including the keel, down to clean barrier-coat. Ten years of paint gone for $600. and I never saw it happen.

higgs · Nov 6, 2011

Re: Bottom painting, where do I start..?

You may want to go over the bottom with a sander to get the growth off, but other than that, for your uses, leave it as it is. What do you care if the bottom isn't racing smooth? Growth on the bottom does not hurt the boat - it only slows it down.

Joe · Nov 6, 2011

Squidd said:
You guys are saying (if I'm storing out of water) "don't worry bout bottom paint" "you don't need bottom paint"...

Your not saying leave it as it is are you..? Surely I need to sand it and coat it with "something" ...? Maybe just a good exterior machine enamel rather than expensive "bottom paint"..??

Forget about the bottom paint issue until you get the fiberglass protected from water intrusion. Bottom paint won't do that, it only discourages marine growth. Get the hull clean and investigate the various epoxy barrier coat products such as those made by Interlux and Awlgrip. Very detailed preparation and application instruction come with these products.

Honestly, whether you apply bottom paint or not on a trailerable boat is question that will answer itself as your season goes on.... if you're only leaving the boat in the water for a few days at a time...... you don't need bottom paint..... but you do need a BOTTOM!

Okay, so after a few times in and out of the water you decide you'd like the convenience of bottom paint...... it will be easy enough to apply over your newly built bottom. Each bottom paint manufacturer will have detailed instructions on application. Most will suggest a 2 part primer when applying the paint to a new surface.... this type of primer is time sensitive and creates a chemical bond between the barrier or gel coat and the paint. Subsequent coats of paint are simply rolled on the previously painted surface......... very simple and easy.

As to the type of paint...... I'm an advocate of local knowledge...... so I'd suggest taking a run down to your neighborhood chandlery for a consultation. The biggest consideration though, is to get a paint that will not lose it's effectiveness when sitting out of the water on the trailer. Some paints that work by emitting their anti-fouling agents over time can be rapidly leached ineffective by exposure to sun and air. They are designed for boats that are in the water year round.

Ablative paints, that work by sloughing off microscopic layers as the boat moves through the water, are not affected by the exposure to air and sun..... and have long been preferred by trailer sailors.

There are many exceptions to this hardshell vs. ablative comparison so keep investigating.

But first, get that bottom rebuilt...... you'll learn all about bottom paints between no and then.

Ken Cross · Nov 7, 2011

I agree with Joe

I trailered for years and he's right. Bottom paint is for longer term in water storage. I only know of one bottom paint not suitable for fresh water. Don't use Interlux Micron 66 in fresh water (but it's fantastic in salt.) I don't know why.

Sumner · Nov 7, 2011

Joe said:
Forget about the bottom paint issue until you get the fiberglass protected from water intrusion. Bottom paint won't do that, it only discourages marine growth. Get the hull clean and investigate the various epoxy barrier coat products such as those made by Interlux and Awlgrip. Very detailed preparation and application instruction come with these products............

But first, get that bottom rebuilt...... you'll learn all about bottom paints between no and then.

Joe made great points and if I was going to take the bottom down to the gel coat, which seems to make sense to me in your case if you decide to do anything, then I'd barrier coat it as Joe outlined. It is not all that expensive. It cost us about $120 for the barrier coat on our 26 Mac. You might need a little more as the bottom on your boat is probably more area.

Here is what we did...

http://purplesagetradingpost.com/sumner/macgregor2/outside-39.html

...and so far it has worked well for us. After 2 months in the water in Florida we had a few 1/8 th inch barnacles starting that I just scraped off with a spatula.

If you are only going to be in fresh water you here a lot of people that are happy with the VC-17 mentioned in the other posts,

Sum

Our Endeavour 37

Our Trips to Utah, Idaho, Canada, Florida

Our MacGregor S Pages

Mac-Venture Links

Barnacle Bill · Nov 7, 2011

I did write an article last spring on bottom paints (Interlux) which might be helpful if you have not already read it. Look through my threads. As mentioned above, you need to clean up your hull and protect it with an epoxy barrier coat. Interprotect by Interlux is a great system and easy to do as a DIY project. (I mean, this is not a fun job, but their projects make it easier than some other systems and because of favorable dry times, you can do it faster with wonderful results).

Gunni · Nov 7, 2011

Those round areas look like blisters to me. Need to get the bottom paint off down to the gelcote and investigate them. Painting over blisters will be a useless effort - they won't hold paint and will only get worse.

r.oril · Nov 7, 2011

Sand and go

higgs said:
You may want to go over the bottom with a sander to get the growth off, but other than that, for your uses, leave it as it is. What do you care if the bottom isn't racing smooth? Growth on the bottom does not hurt the boat - it only slows it down.

I was all rapped up in painting the bottom until I listened to these great members.

I did buy the expensive paint before reading these types of posts.:cussing: Now the paint sits in my shed. I did sand/waterblast off the junk. The bottom isn't pretty but you can't see the bottom in the water. I do rinse it off when I get home.

joes new addiction · Nov 7, 2011

I no sailboat expert by no means, not a boat owner (or sailer) for long, but I can relate what was told to me.
I bought a small 16' American last July.
Gel coat was solid, a few scratches, but solid and dirty no matter what I did to clean her up.
Being a anal motorcycle/old car mechanic, "I'll just paint it".
Talked to the captain that taught me at the ASA course, (happens to own a body shop and has a stunning painted 22" Catolina).
Told me if she's a trailer boat, just use expoy paint on the hull, pressure wash her after you get home, if she lived in the water for long periods anti-fouling.
Makes sense.
Off I went.
Picked up the paint at a local paint supplier.
Not knowing how deep the gel coat was, I wet sanded with 320, washed it down with a pressure washer, wiped with wax remover, reducer. (like doing a car, I figured)
Rolled the primer on with a foam roller and brushed the marks away.
Looked like glass when I was done!
Came back an hour later for the first coat of top coat, and the runs, well they looked like waves!
Painted it and was told later after it hardens up, sand it all smooth and repaint, (just sold her with the "waves", repaint? or sail? sail!
lesson leaned- give the paint a chance to "grip" the gel coat! sand her with 100, maybe a sealer down first, I was thinking a light spray coat of sealer.
Just bought a PT 1/4 22', gonna paint her (anti fouling, cuz she live in the fresh water here in NEPa.)
Joe
you only make the same stupid mistakes once or twice!

Sumner · Nov 7, 2011

joes new addiction said:
...I wet sanded with 320, washed it down with a pressure washer, wiped with wax remover, reducer. (like doing a car, I figured)....

...lesson leaned- give the paint a chance to "grip" the gel coat! sand her with 100.....

Most paint companies recommend 80 grit to get the "grip" you talked about, but always check the spec sheets on what you are using.

I had to sand the gel coat for the bottom paint anyway, so putting on 2 coats of Sea Hawk's Tuff Stuff for a barrier coat only added a couple hours to the painting and less than $130 to the total cost. It has a higher build film than some others, so 2 coats is what they recommend in most cases,

Sum

Our Endeavour 37

Our Trips to Utah, Idaho, Canada, Florida

Our MacGregor S Pages

Mac-Venture Links

Harry McCoy · Nov 7, 2011

Joe..you are right in my backyard so to speak during sailing season...must be talking about captn Art Phillip. Please check out our sailing club"Paupack Sailing Club" see the club .website....good company, camaraderie and racing every other week in season if you desire...annual dues $30 cheap, $60 racing. Harry Mccoy, treasurer

mudtertel · Nov 7, 2011

One more thing, when sanding to gelcoat. I would put on Epy Glass, it soaks into the gel coat , then put on the barrier-coat (5 coats , I used Interlux 2000E) A gray coat then a white coat then a gray coat and so on.

sailme2 · Nov 7, 2011

Bottom Stripping

A few years ago I had to strip the bottom of my Pearson 30....blisters, old paint, etc.
I used a product called Starten www.starten.com.
It comes both as a thick gel and as a liquid. Use the gel for the heavy stripping and the liquid for cleanup and small tight areas.
I've used many kinds of stripper over the years, but this one worked! Worked right now, first time! Put it on according to the directions and take it off with a putty knife. Very little sanding involved.
After repairing the blisters with epoxy I used Interlux Barrier Protect for the first 2 coats, Then followed up with 3 coats of VC17.
I'm in Lake Huron and the boat is in the water all season.
I can see where having the boat on a trailer might not require the drastic measure I used, but after going to the trouble of cleaning up a bottom that looks like your pics just might justify the extra work and expense.
By all means, though check out the Starten. It makes life a lot simpler.
Good luck

Bottom painting, where do I start?

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