Looking for Low VOC paint

What I'm looking for in a top coat is a non-isocyanate water borne 2k (two part) single stage (no clear coat) paint. Can someone point me in the right direction?

Eric Nelson
F-25c.blogspot.com

 

Google ?

 

Welcome to the forum.

The only true low to zero VOC two part marine paint is epoxy. System Three sells their WR-LPU which has reasonable performance for the price, though still not as good as a true solvent base LPU. These paints (waterborne epoxies) typically are lacquer dry types, but new advances have been made in recent years with different drying agents, though the jury is still out on these for the marine environment, particularly in the polyurethanes. This suspect can get pretty complex.

 

I've tried the WR-LPU many years ago. My HVLP sprayer dried it out too much and I ended up with orange peel. I'm reconsidering it since I'm working on the boat in a storage unit that is adjacent to other units and solvents can travel over to the other units. My sprayer is an automotive quality unit and a also have a air supplied respirator but I can't go the old style automotive paint without constructing a paint booth in the space.

My searching indicated that there are a lot of water bourne paints out there now like the PPG Envirobase, but like the WR-LPU they seem to require a clear coat (2 stage) for exterior finish. Also the PPG seems to still use a solvent reducer. Anybody out there try PPG Envirobase or similar on their boat?

 

I've used WR LPU on several projects in the past, both spray and roll, with decent results. It has held up very well. Note that the instructions call for thinning with something like 20% water, which may help with the HVLP drying issue.

 

At the time I remember I did the 20% water dilution. I think I had good results at first and had orange peel on a later spray. I remember that the paint is a real pain to sand off to correct a bad result. If I decide to use WR-LPU I'll get an extra hose section for the sprayer and maybe run the hose through an ice water bucket too.

Any other options besides WR-LPU for a water borne marine paint?

 

Looks like PPG has a full water borne system now. I'm not sure if I can get all the products locally or how expensive the stuff is:

D8012 Waterborne Epoxy Primer
Envirobase High Performance waterborne basecoat
D8186 Waterborne Clearcoat

 

Environmental control is the key to the water borne LPU's. Gun type also has a role. I've tried to squirt WR-LPU and had limited success. The best I got was from an old remote Binks pressure pot setup, in an air conditioned space, with compressor cooler too. Turbine HVLP units dried to the touch nearly right out of the gun, standard gravity fed HVLP guns worked slightly better, yet still couldn't get rid of the stipple before it gassed out. The environment has to have an unusually high humidity, for these paints to spray successfully, all the while keeping temperatures in check.

 

That is partly why I keep searching for options, like PPG & DuPont, instead of just going with System 3. I have a gravity feed HVLP, but I'm in Colorado and it's really dry here! It will be much cooler in the morning by the time I've faired, skim coated, primed, and am ready for top coat, but it will be our driest time of the year.

The PPG Envirobase and Aquabase have a system to adjust for the temperature and humidity at the cost of a solvent reducer. I don't know how bad that reducer smell would travel and I'm don't know whether the PPG water borne clear coat is non-isocyanate.

 

I'm not that familiar with the new offerings from PPG and DuPont, having had my fill with these second generation water bornes. Advances have been made, but the solvent based stuff still works, applies and lasts better, so . . . The automotive manufactures have been struggling with these paints for some time and they have perfect climate control, plus robots doing the work. This leads me to think a mere human can't come close, especially in a home build environment.

 

I hear you PAR. I like acrylic urethane myself. It does seem like the water borne paint requires an even more clean shop. I've seen some refinisher reviews saying they've had good luck with the new water borne paints but these were refinishing professionals.

Have you every used the SilverTip Yacht Primer epoxy paint?

 

Yes, I've used the System Three waterborne primer, though this is a bit of a misnomer. It's water clean up, but is still a petroleum base product. The addition of an emulsifier, permits water clean up, though you do have to scrub pretty good, nothing like the acrylics. This particular primer will cure hard as stone, in spite of water. I had a tray of primer that I intended to clean out, but didn't have time when I put it down. I figured I'll just drop the whole thing in a 5 gallon bucket of water and would get back to it after I finished up. Well I forgot about it and a few days later pulled the tray out of the bucket, to find the primer was completely cured.

The System Three stuff works well, but you do need to sand it within 3 days of application or it becomes much harder to do.

I too use acrylic urethanes, but much research needs to be employed for the application as the polyurethanes and acrylic urethanes have distinct advantages and disadvantages. Solids content tends to be higher on the polyurethanes, but these also are a bit harder for the backyard builder to work with. The acrylics tend to be thinner and much more clear, but also cost more. the percentage of urethane to acrylic can be a factor as well, particularly if you need something more rigid or more flexible. Lastly the naturally lower VOC levels in the acrylics has an appeal to some.

In the end, it's really experimentation and comfort level. This will be based on shop conditions, skill and equipment levels too. I'm using some industrial, some automotive and some marine finishes. I use epoxy primers regardless of top coat, just because I've been screwed too many times in the past. Interestingly enough (at least in my case), the better you get at applying a finish, the more costly and difficult to apply these finish products seem to become. Damnit . . .