Water based primers

Completed my first RV in 2005 and now starting a second RV; medical issues have prompted me to want to avoid the two part isocyanate epoxy primers...I'd appreciate hearing thoughts and experiences with the newer water based primers for interior parts.

I've used the Stewart Sytems waterborne primer with good results. Dan and crew are great people to work with and very helpful.

I primed my steel fuselage side steps in a water based primer (maybe Stewart systems??) and the primer peels off in sheets. It also gummed up my sprayer to the point I trashed the sprayer (cheap HF model) and the remaining gallon of primer. Didn't have these issues with Akzo used elsewhere

I used Stewart Systems waterborne primer for my empennage and wings. More accurately, the original builder did most of the empennage, I carried on with the same primer. I found it works very well for skins, ribs, etc. It takes a little longer to harden enough to do well on things like the corners of aileron & flap hinge brackets. I just used a little airbrush to touch up where needed. No complaints here, including none from my wife or neighbors complaining about the smell (there pretty much is none). No issues cleaning up equipment here.

I used Stewart systems about 5 or 6 years ago to prime inside of my Tripacer wings and have had no issues with it. I also used there system to paint all of the sheet metal ( water based primer and there 2 part waterborne paint) and it looks as good as the day it was put on. I plan on painting my RV9 with it. So far it seems fairly durable. I also painted the fabric on one wing with the waterborne paint and it still looks good.
I only painted when the temperature and humidity were within there recommend range, and was sure to get the correct viscosity.

Mike

Stewart Systems

I have been using Stewart Systems primer on almost everything so far. I love that I can clean it up with soap and water. Even better is the lack of waste. I pour more than I need into the paint cup, do the painting that I need to do then I pour the remainder of the primer back into the paint can to be used another day. Very little wasted material unlike two part primer. I made a mistake on a part (don?t tell my wife) and had to remove the primer. It did not come off very easy! I have painted some inside of skins and my wife came into my shop and said that if she didn?t know I was painting she would of never known ? No fumes or lingering smell. I plan to continue Stewart Systems.

posterman said:

Completed my first RV in 2005 and now starting a second RV; medical issues have prompted me to want to avoid the two part isocyanate epoxy primers...I'd appreciate hearing thoughts and experiences with the newer water based primers for interior parts.

Click to expand...

Two-part epoxy primers such as AKZO are not isocyanate cured. While they don't have the easy clean-up of waterborne primers, two-part epoxy primers are generally quite a bit tougher.

I've used the Stewart Systems primer for my wing ribs and rear spar; it seems to be holding up well so far. A washdown with Krud Kutter metal prep and a very thorough rinse seems to give good adhesion for the primer, both the Stewart Systems and the Rustoleum aluminum primer spray-can I've used for the occasional one-off part that it's not worth dragging the whole spray setup out for. Just be warned, the solids like to settle in the primer after a while, so you'll spend a good bit of time breaking them off the bottom, crushing the clumps, and mixing them in.

Get a Harbor Freight HVLP spraygun and have at it.

I, too, use the Stewart Systems primer ... it adheres well after a good cleaning with Alumiprep surface enchant. The solids do settle .. I bought an impeller-type paint mixer from the aviation paint isle at Home Depot. Chuck it into the Dewalt, set to slow, and go at it. My first gallon can from Spruce was pretty dense at the bottom. After 10 mins, I got everything mixed back in. Now, I use it regularly enough that a 1 min mix is all that's needed.

Appreciate all the responses

Thanks to all who responded...I plan to give the Stewart Systems primer a try based on the posts on what is now a second RV purchased as an abandoned project, an RV6 with tip up (slow build) - I plan to build and convert it to a 6A with slider.

Do you have any reports back on this?
I am also thinking about trying this
I had a person in my EAA chapter that swears by it. I heard the biggest downfall is the added weight of water based primer