Making latex paint smooth

[Openboater]

I just posted on what did you do in your shop today about painting the hatch boards on my sailboat with exterior latex, and that I was having trouble making the finish smooth. Here's what I'm doing:

1. I've primed it.
2. I'm using a bit of water to thin the paint a bit--it's really soupy.
3. I'll put on 2 or 3 coats and sand with 150 between coats.
4. I'm using a damn good varnish brush to apply.

Am I on the right track here to end up with a smooth finish? Thanks. Tom

 

[theoldwizard1]

It sounds like you want a "automotive" type finish. You'll never get there with latex paint, especially with a brush. The best you can do is spray with an airless sprayer.

One thing to remember about latex paint. It takes over 30 days for it to completely cure. Sanding will tend to make it "ball up".

Something you might try. Get the finish as good as you can. Let cure (that 30 day number is with temps above 60). Apply a good coat of past wax. Get a power buffer and go at it. Repeat.

 

[laser3kw]

I am not an expert
What temperature are you working at?
how did the primer lay down?
are you block sanding or free hand?
are the surfaces horizontal (flat, face up) or vertical
150 sand paper sounds course. Maybe finish the 150 sand job with 240
I had trouble using a brush, always had streaks that would not flow out.
I use a roller with 1/2 nap for my go to problem solver. But rollers are a ***** if there are alot of edges.
I am not an expert - my experience may not apply to your situation.

 

[May Pop]

There are additives to make it flow out (smoothen). Any paint store or Home Depot has it. I believe one is call flotrol.

 

[nicksnothereman]

I just posted on what did you do in your shop today about painting the hatch boards on my sailboat with exterior latex, and that I was having trouble making the finish smooth. Here's what I'm doing:

1. I've primed it.
2. I'm using a bit of water to thin the paint a bit--it's really soupy.
3. I'll put on 2 or 3 coats and sand with 150 between coats.
4. I'm using a damn good varnish brush to apply.

Am I on the right track here to end up with a smooth finish? Thanks. Tom

That sounds like a lot of work. Why would you thin paint with water? I'm not sure that makes sense. I've used bleach before for rocks (true story, worked well when dipping) but I'd assume to actually "thin" paint you'd want paint thinner or ammonia. Ammonia would probably be less effective so in theory it would be harder to go too thin.

Smooth finish (if I care to do it) I use foam brushes or a roller. Don't know how well that would work for a boat. Honestly, at the point where you'd spend this much time doing this you should probably just pay a professional. I mean...you own a boat you probably have a couple hundred bucks laying around to pay a dude to mess it up.

 

[Openboater]

I am not an expert
What temperature are you working at?
how did the primer lay down?
are you block sanding or free hand?
are the surfaces horizontal (flat, face up) or vertical
150 sand paper sounds course. Maybe finish the 150 sand job with 240
I had trouble using a brush, always had streaks that would not flow out.
I use a roller with 1/2 nap for my go to problem solver. But rollers are a ***** if there are alot of edges.
I am not an expert - my experience may not apply to your situation.

Thanks for the replies, especially about how long the latex paint takes to cure. I noticed it doesn't sand very well (after a couple of hours--my bad).
I have a tack room I keep at a higher temp...would that help?

To answer the questions above: my shop sits at about 60F, the primer didn't go on too well--kind of streaky, the surfaces are horizontal to paint, I'll try less coarse sandpaper, I have a couple of small rollers I can try.

Thanks again for the advice. Tom

 

[Just Primer]

Sometimes it is just the product your using. Different companies have better paint.They are not all the same. Flotrol might work though. I have use that before with good results. A foam roller might be a good idea to try as well. I have never painted a boat. I am a paint contractor though. Have been painting since 91. Mostly residential redo's,

 

[Openboater]

That sounds like a lot of work. Why would you thin paint with water? I'm not sure that makes sense. I've used bleach before for rocks (true story, worked well when dipping) but I'd assume to actually "thin" paint you'd want paint thinner or ammonia. Ammonia would probably be less effective so in theory it would be harder to go too thin.

Smooth finish (if I care to do it) I use foam brushes or a roller. Don't know how well that would work for a boat. Honestly, at the point where you'd spend this much time doing this you should probably just pay a professional. I mean...you own a boat you probably have a couple hundred bucks laying around to pay a dude to mess it up.

Ha ha. This is a 17 foot sailboat my friend--ain't no 100s laying around this joint. And I prefer to do the work myself--that's what my shop is for. Latex paint thins with water--it's water-based. I've never heard of using bleach. Any other opinions on that?

I have foam brushes I use for Cetol and varnish. They work well. Maybe I'll try one...

Thanks for the ideas. Tom

 

[Openboater]

Sometimes it is just the product your using. Different companies have better paint.They are not all the same. Flotrol might work though. I have use that before with good results. A foam roller might be a good idea to try as well. I have never painted a boat. I am a paint contractor though. Have been painting since 91. Mostly residential redo's,

I'll try the foam roller--I've got a very small one sitting around. I've heard of Flotrol--I'll look for it. Thanks. t

 

[Steevo]

+1 for Flotrol
That and a good quality name-brand latex, applied at a temperature within the manufacturers specified range.

 

[retrobuilder]

A Sherwin Williams shop can add a flow enhancer also a good brush and temps in the 60-70's.. Big box paints are about one coat not finish.

 

[slghmmr88]

+1 for Flotrol
That and a good quality name-brand latex, applied at a temperature within the manufacturers specified range.

Make that +2 for flotrol.

 

[theoldwizard1]

Google "roll and tip". Technique common used on boat hulls. I don't know how well it will work with latex.

 

[Ross/Kzoo]

Not sure why you're using latex.

 

[Krodad]

That's my question as well.

Exterior latex paint is made to be very heavy bodied, able to get many mils in one coat, and stay flexible. They are not considered a particularly durable finish in terms of traffic at all. They are durable in the sense that they can deal with temperature extremes and swings, and move with the substrate.
In your case, the hatch covers would have been better painted with a single stage alkyd with urethane solids as a minimum, or better yet a two part urethane. If you are going to be walking on the hatches they will look pretty bad pretty quick. Exterior latex just is not designed to flow out and give a smooth finish, and a foam roller is going to impart some pretty serious air bubbles into the finish. Remember this type of paint is designed to go on in thicker coats and hang on without running, so it's not made to self level out the way a solvent based coating will, or even the newer waterborne interior trim paints.

You have it on there now, and it's not a great idea to go putting a solvent based coating over a latex, so do your best, keep things on the cool side while painting to give it some time to lay out and not drag. Eventually I think you will be stripping it down and doing it again.
As a last resort you could spray the latex on with an airless. This will give you the best finish for the coating you have right now.
Exterior latex does not sand for squat...it's too soft by design.

Sorry to be the bummer, and good luck!

 

[Ed Litsch]

The only way I have ever gotten latex to smooth out without any lines is to lay it down in the hot sun- like when you paint a metal door. Then I can pretty much guarantee it will come out pretty smooth.

 

[Openboater]

Exterior latex is actually not a bad product for a marine environment. Many small boat owners use it and semi-gloss holds up quite well. This application is for vertical hatch boards, so there is next to no use except opening up the boat when I arrive, and closing it up when I leave. The boat is small and I never put the boards in when I sleep, I just use a canvas drape that works fine for me.

I've used varnish and varnish-like finishes for many years, and use them still on the other bits and pieces on board. But I wanted to use a color for the boards just for the change. I appreciate all the helpful advice. In the end, I'll probably achieve an acceptable finish on the boards, and will have learned a lot in the process. Tom

 

[spotco2]

I've painted several boats over the years and normally use a marine paint with an additive to make it lay down and use a roll and tip technique. It looks sprayed when finished.

If you are using regular house paint, you might not get the same results. Try some flotrol, use a GOOD foam roller, then tip out with a badger hair brush for best possible results.

 

[theoldwizard1]

I've painted several boats over the years and normally use a marine paint with an additive to make it lay down and use a roll and tip technique. It looks sprayed when finished.

If you are using regular house paint, you might not get the same results. Try some flotrol, use a GOOD foam roller, then tip out with a badger hair brush for best possible results.

A WINNER !! TWICE !!!!!

 

[Mr.N]

Why are you not using an oil based paint?

For oil base thinking at home I drop the gallon paint can in a two gallon bucket filled with hot water. Then just apply with a brush and the paint will settle without large brush marks, might take a little practice with the brush. Then a little sanding and off to the next coat.

 

[Jim B]

Why not use Interlux Brightsides. It's a polyurethane I believe. It's easy to apply with a brush, flows out perfectly and stands up well to the marine environment. I've used it paint everything from shear stripes to a compass cover and all with a brush. If you started with a good sanding sealer, then sanded then applied the Brightsides I think you would have a real nice finish. I found that additives to improve the flow of latex paints tends to leave the dried paint finish kind of soft.

 

[Openboater]

Thanks for the continuing advice re: coating choices, but for a number of reasons (maybe not as good as the ones you guys have put forth for alternatives, but ones that satisfy me...), I landed on exterior latex.

I think a small foam roller with a good tipping brush is the answer to my original question about a smooth finish. That's what I'll do. Thanks again for your expert advice. Tom