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Queston on EkoPoxy Primer...

Reflex

Well Known Member
I thought I'd give Stewart Systems EkoPoxy primer a try. This evening I got all set up to spray and opened the first can (part A). The consistency of part A is what I would call extremely thick. It's roughly that of window glazing or maybe comparable to canned dog or cat food. In fact, as I write this from my shop, the stirring stick is still standing straight up in the middle of the can.

For those of you who have used EkoPoxy primer, can you tell me if this is normal? If so, how do you measure part A. Also, if this is the norm, how do you get it out of the can...perhaps a spoon?

Thanks and have a great 4th.

Fred
 
I have zero experiance with ekopoxy, but I bought sherwin williams fancy airplane epoxy and it was half liquid and half what you described. I figured out the hard way that it needs to be on a paint can shaker before you try to mix it. I dont know if yours is the same way.
 
I thought I'd give Stewart Systems EkoPoxy primer a try. This evening I got all set up to spray and opened the first can (part A). The consistency of part A is what I would call extremely thick. It's roughly that of window glazing or maybe comparable to canned dog or cat food. In fact, as I write this from my shop, the stirring stick is still standing straight up in the middle of the can.

For those of you who have used EkoPoxy primer, can you tell me if this is normal? If so, how do you measure part A. Also, if this is the norm, how do you get it out of the can...perhaps a spoon?

Thanks and have a great 4th.

Fred

I had a similar experience with EkoPoxy, Fred. This happened last September. I could not get the Part A to come to anything smoother than "chunky", but decided to add Part B and the recommended dose of water to see if that would help. Then I mixed it like crazy and when I thought it was good enough, put it through a paint strainer then into the gun. I had to force it through the paint strainer with a tongue depressor as it was still lumpy.

This mixture sprayed very poorly. I could put on a fine mist, but as soon as the droplets started to coalesce it would sag and run, while still having so little coverage that I could clearly see the substrate. Very disappointing. Everything I sprayed on had to be sanded off; once this stuff dries it is like epoxy, hard as nails, so sanding it off is hard work.

With this in mind, I called up Stewarts and talked to Dan. He immediately indicated the product was faulty and offered to replace it without hesitation (and without me having to even suggest it). The new EkoPoxy was a totally different beast - it came out of the can easily, mixed easily, and sprayed well. Oh, it, too, is hard as nails. Very impressive stuff once its dried.

As far as recommendations go, I would first look at the date code of your product - if it is getting close to a year old and hasn't been stirred regularly then you may need to stir it quite a bit to get it to break up. The recommendation for this product when it is being stored is for it to be agitated on a monthly basis.

When in doubt, call Stewarts. In my case, they had a product problem and couldn't have been better about making it right. Top notch customer service. Now the EkoPoxy has been on our airplane for a few months I have to say I'm glad it's on there because I know the airplane underneath that primer is well protected. Next month I'll be applying the EkoCrylic top coat.
 
Gentlemen,

Many thanks for your quick replies.

C. Joy, your story sounds like an exact copy of what I did this evening. I was using a new primer gun (3M Acccuspray) so I was spraying a practice kit just to try out the new primer and gun. I should know better than to change two variables at once.

I too took a "chunk" of the primer and decided to mix it based on weight rather than volume. The directions are on the side of the can doing this. My experience was the same as yours in that it wouldn't even go though the screen at the recommended mix.! Since this was "experimental", I decided to reduce the primer significantly. Using distilled water, I thinned the paint to a point where my "gut" told me I was good to go. The results were similar to yours although some of the parts came out very well.

On a bright note, to those reading this, the 3M Accuspray is one of the best purchases I've made in quite a while. It actually tried to spray this stuff and some of the pieces are even acceptable/good. Clean-up was under 3 minutes and worked just like the video on You-Tube.

I'll give Stewart Systems a call on Tuesday as this can is only 45 days old. I really liked the lack of fumes and the water clean-up. I'm going to try Ekopoxy again after speaking with them.

Thanks for the responses.

Fred
 
I had the exact same issue with a can I ordered in January from Spruce.
Stirrer would just get 'stuck' in the actual paint. Mixed it as recommended, it however still had (at least) a honey like consistency. Tried to spray it anyway with the 3M Accuspray gun, even though I knew from spraying other paints that this will not work, only to learn that this was indeed the case.

I then ordered another can directly from Stewart, which was MUCH better. Mixed it again as recommended, this time with OK results. I however still thought that it the paint is a litte bit thick, so added more water and am now happy with the results.

I also called Andy from Stewart, who was very friendly and offered to replace the old can. As I would have had to ship it back on my expenses, I decided to simply add water until the consistency was similar to the new can, what worked fine.

By the way - I bought a postal scale and weighed the individual components based on the volumetric ratio (5:1:1 + the water I decided to add). This allows me to also precisely and consistently mix smaller quantities.
 
Sounds like the result of improper storage to me (not necessarily on your part, possibly upstream). I bought a gallon of EkoPoxy for my fuselage, figuring I might just use it as a topcoat in the interior. The first weekend after it came in, I cracked open the can, mixed up a small batch, and shot some test batches. It mixed up nicely, sprayed great, and in general I was pretty satisfied.

I then put the cans under my workbench and went back to working on my ailerons and flaps. It was a little over two months before I finally had some fuselage parts ready for primer - in this case, the gear tower components. I carefully cleaned and etched them, and once they were dry, I got ready to mix my primer.

This is what I found when I opened the can:

IMG_5829.jpg


Basically primer pudding. I took a closer look at the can and saw an important bit of information I'd missed before: "Store in a cool dark place, not to exceed 100°F."

Guess what does not meet those standards? A garage in Houston. Since the primer was fine before, but not now, it seemed to stand to reason that my failure to read the instructions was the reason it had gone to ****.

I ended up just going back to the rattle-can primer I'd used up to this point. It originally took me several weeks to get that gallon of EkoPoxy, and I was unwilling to wait that long again, especially since I had parts etched and ready for primer already.

It was a pretty sad moment in my build, because as you guys know, that stuff was a long ways from being cheap.
 
"A picture is worth a thousand words". I should have posted a picture when describing the problem. Mine looks similar to yours. Below is a picture of a quart after adding 30cc (1 ounce)of distilled water and mixing (or trying to mix) for roughly 2 minutes.

I looked up my order and found the I received the can on May 4th. I keep my shop at about 78 degrees and 35% humidity. My thought is that this one was probably in stock for a while. My order shipped quickly and only took about a week to get. I'm hoping I'll be spraying again next weekend or perhaps in the next 10 days.

Thanks for posting the photo! A picture of my batch is below.

146ffdfa-70c3-4a96-99e7-641eb10fe457.jpg


Fred
 
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Yikes! Your paint looks even thicker than mine.
Did you try to add some distilled water? Worked for me, but then I might have had a different issue.

There is a batch number on the ExoPoxy can, which reveals the data on which it was produced. Mine was from autumn of last year. After I received it, I put it right into the basement, which is constantly cool and dry.

I was however also wondering about what happened on the way to / from Spruce? When I ordered it, the paint might have actually become frozen during transport.
 
Years of storage in high temps.

I have stored mine and continously used it in my shop in the Arizona heat (100F) for years. Yes it does congeal a bit but once it is mixed with the other part I was always able to use it without issue.

Your mileage may vary.
 
Just a quick follow-up

Just a follow-up to the final results of what I've encountered.

Spoke to Stewart Systems on Tuesday the 5th. Nice folks and they were cooperative. They said that I may have gotten an older batch and that there are times when the paint can thicken. Ordinary, when they mix it with a drill it comes back to normal consistency. They suggested I try mixing with a drill and mixing bit rather than manually.

I mixed the quart with a drill and mixer bit. Unfortunately, the paint was so thick that most of it ended up on the mixer in a blob. It was only a quart can so about half the can ended up on the mixer.

I called Stewart Systems back and they sent out another quart. They didn't have the color I wanted in stock, so it was mixed and was "fresh" when I received it. I took it out of the box, popped the top off, and found it to have viscosity similar to other paints I've sprayed. I put the top back on the can, added the shipping clips to insure a seal, put the can in Tupperware, and stored it at 78 degrees and 35% humidity.

Last night, I opened the can to prep for priming and found the can to have reverted back to a cookie dough like thickness. I knew better than to try and mix it with a drill and mixing bit as I would end up with most of the can on the mixer. That would be expensive.

Instead, I went at the can with a basic mixing stick. After the stick broke and I upgraded to piece of 1/4" aircraft ply and worked on it for about 10 minutes. After 10 minutes I decided that the paint was as good as it was going to get. There was very little improvement. I decided to use the paint anyway and mixed it using a postage scale. I ended up mixing it 5 parts paint, 1 part hardener, 1.75 parts distilled water. In the end it sprayed very nicely and dried in an incredible hurry.

Believe it or not, I'm going to continue to use the Stewart Systems EkoPoxy. Although I'm disappointed with the way it mixes (difficult and very messy as much of it sticks to whatever you're using to put it in a mixing container), now that I know how it works I can deal with that. For me, the benefits far outweigh the hassle of using it. I really like the clean up, the lack of smell, and I feel safe using it (lungs, fire, environment, etc.). It cleans up very nicely with water or a bit of rubbing alcohol. It also sprays very nicely and I can dimple after the paint has dried for only a couple of days.

So why the post? If you're running into the same problems, it's my opinion that it's just the nature of the product. Use a postage scale and patience.
 
I'll post a follow-up, too.

My experience with the EkoPoxy primer started off with product that pretty clearly was bad. A new can of primer fixed that up (no charge from Stewarts - they have no trouble standing behind their product).

I've since moved on to the topcoat, using EkoCrylic. This material mixes very well. Note that, by weight, the recommended mix ratio is 4:1:1. This produces almost exactly the 22-24 second viscosity measurement that's recommended.

I'm shooting two colours, Insignia White and Pontiac Red. They seem to shoot differently, however that may well be attributable to the red being much easier to see. As a general guideline, if you haven't painted with this stuff before and are using white and a darker colour, start with the darker colour first. It's just a lot easier to see how the paint buildup is happening. The white is a challenge in that respect.

In terms of opacity, the white is what I would classify as poor. Especially over smoke grey primer. I've had to use a tack coat plus four build coats, then the wet coat, to get anything like the required colour saturation. In one place I have a localized touch-up done with smoke grey primer. I have five colour build coats there and can still see the outline of the grey primer.

The EkoCrylic is a very hard paint. After even a day of cure time it is hard work indeed to sand it off. It also produces fantastic gloss - every bit as glossy as one would expect from a basecoat/clearcoat finish, without the hassle. I can also attest to its ability to be cut and buffed - it responds well to 600 grit wet sanding for removal of orange peel. If you can't get to the point of producing an orange peel-free finish, put on lots of paint so you'll have enough to cut and buff.

I've had zero troubles with pinholes, fish eyes or solvent pops. I'm painting a composite aircraft and was expecting to have most, if not all of these little evils arise somewhere along the line. So far, so good. By the weekend I'll be applying the Pontiac Red to the fuselage and hope it goes on as well there as it has on all the smaller, removable parts.

Updates to follow.
 
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