# Stewart Systems

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#### Little Scrapper

##### Well-Known Member
HBA Supporter
Log Member
17 days ago at Oshkosh I visited the Stewart booth and had a great chat with them. They gave me a sample of finish on fabric. Every day for 17 days so far I've had this in and out of my pocket. I crumple it up as hard as I can then flatten it out trying to delaminate it. I crumple it approximately 50 - 80 times a day if I were to guess. When I'm driving between service calls I do it non stop. I'm starting to wonder when it will delaminate.

Has anyone used Stewart Systems here? I'm curious if the smell is much less than the others.

#### gtae07

##### Well-Known Member
I have used their EkoPrime on parts of my RV.

Pro:
Very little smell.
Seems to stick well once it's on the parts. Even the runs and drips are rock-hard and stuck on.

Con:
Very difficult to make it "behave"--it gunks up the HVLP gun, it runs, it is very sensitive to humidity and temperature.
It's expensive.

I got good results on my wing ribs, so-so results on my wing skins, and middling to very poor results on the fuselage parts. I used a rattle-can primer on my latest round of parts (forward fuselage frames and skins) and it seemed to perform much better, if smellier and nastier.

#### TFF

##### Well-Known Member
To me the only advantage is the Ekoprime and the glue. The glue Im going to try with stits. Even though the top coat is waterborne, the spraying is as toxic as Aerothane. It is also one of the heavier top coats. Looks good though.

#### Dana

##### Super Moderator
Staff member
Stewart's Ekobond is the same thing as 3M Fastbond 30NF, which is cheaper. I used Fastbond when repairing the rib stitching on my Fisher.

Dana

#### 57Marty

##### Well-Known Member
To me the only advantage is the Ekoprime and the glue. The glue Im going to try with stits. Even though the top coat is waterborne, the spraying is as toxic as Aerothane. It is also one of the heavier top coats. Looks good though.
Hi All,
I was one of the instructors in the Stewart's System workshops at Airventure this year. As to the comparison with Aerothane; EkoPoly and EkoPrime are not at all toxic like Aerothane. Aerothane uses MEK as a reducer; highly toxic. EkoPoly uses distilled water from the grocery store as the reducer. Clean up is done with soap and water, very simple. The protection needed for spraying EkoPoly is simply a charcoal respirator. One of the best indicators of the safety of the product is that it can be shipped by common carriers overnight as it is not a hazardous materiel.

Regarding issues with application using an HVLP gun, I would like to know what set up was used that caused problems. Most issues with painting revolve around not enough air to the gun and water contamination in the air lines. To properly apply Stewart's finishes I use a Finishline 4 by DeVilbiss. Like most HVLP guns, the required air can not be supplied by a small, single cylinder air compressor. The requirement from DeVilbiss calls for 13 cfm with about 25psi at the gun; that's a lot of air. The air also needs to be cool and dry, using a number of water traps is very important. Cooling the air reduces the risk of water condensing in the hot compressed air coming out of the compressor cylinder. Put your hand near the output of your compressor (before it goes into the storage tank), you will be amazed at how hot the air is at that location. Their are a number of commercial chillers available. A simple cooler can be made by having your air run through a coil of copper tubing that is in a large tub of cool ice water. The coil needs to be between the output of the compressor cylinder and the input to the storage tank. A water trap is also needed between the end of the coil and the storage tank. Further problems come up when the small standard 1/4" air hose fittings are used. Increasing the fittings to 3/8" will greatly increase the amount of air. Without the proper amount of air the finish will not flow from the gun properly, causing poor flow out of the tip and gunking of the gun. It is also very important to use a flow cup to properly reduce (with distilled water) EkoPoly. A flow rate of 24 seconds from a calibrated flow cup is necessary. In higher or lower than optimum humidity settings the flow can be reduced or increased as necessary. All of these issues related to painting are addressed on our videos (DVD's and Youtube).

I would suggest that if you are interested in trying the produce we do have a sample kit available that includes all the materials to do a small frame covering job. It also includes the instructional DVD's and current manual. If you have any questions, please contact me. We also do three day workshops around the country where we go through the entire process from covering to paint. Let me know if I can help in any way.
57marty
mafeehan79@yahoo.com

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#### Aerowerx

##### Well-Known Member
....Every day for 17 days so far I've had this in and out of my pocket. I crumple it up as hard as I can then flatten it out trying to delaminate it. I crumple it approximately 50 - 80 times a day if I were to guess. When I'm driving between service calls I do it non stop. .....
You know, Little Scrapper, you can get medicine now to help conditions like that.:gig:

#### Dan Thomas

##### Well-Known Member
Local fellow here did his Super Cub with Stewart earlier this year. We're watching to see how it holds up. I think Stewart has been around for some time so there should be testimonials available as to its longevity. Many finishes tend to harden and become brittle with time, so Scrapper's informal flex check can't determine how long it will stay flexible.

My uncle used the Blue River waterborne process on his Champ in the early '90s. It was terrible stuff. In cool, damp weather the fabric would expand and sag. Tapes would come loose. We had a Citabria that had also been finished with Blue River and I had to strip the whole thing and recover it with Poly-Fiber. The Blue River tapes were peeling, the finish was peeling, everything cracking. The entire business soured some folks on waterborne finishes. Blue River no longer has the STC for that system; I think the FAA might have pulled it. I would hope that the Stewart is an entirely different and far superior product.

#### TFF

##### Well-Known Member
Its in the mist form if inhaled will hurt you. Polytone or dope have the toxic chemicals that your body breaks down; as bad as it is your body can heal from it. Two part stuff hardens inside you and is there forever. You really need forced air hoods vs charcoal mask.

#### Kyle Boatright

##### Well-Known Member
I so much want to hear multiple anecdotes of successful 10+ year old Stewart Systems recover jobs. There just don't seem to be enough legacy customers out there who report back 10-15 years down the road. On the front-end, I know people had serious problems properly applying the finish coats, but I understand the revised products are easier to spray.

#### 57Marty

##### Well-Known Member
Quick note on the old Blue River System. Blue River was one of the first water based systems on the market and it had many issues but it is not related in any way to Stewart's System. Blue River was water based; the paint mixes at a molecular level with the water. A water born system like Stewart's only uses the water as a carrier and thinning agent for the paint; water is not part of the paint. Stewart's System originated as Aircraft Finishing Systems, being bought by the Stewart brothers in the early 2000's. Dan and Doug bought the company after using the system but not liking the customer service. Andy Humphrey bought the company when the Stewarts retired about a year and a half ago. Andy has made a number of improvements to the system; specifically increasing the pot life of the paint once it has been mixed.

As to testimonies; the oldest covered aircraft using the Stewarts Systems are about 15 years old; many in Alaska. Take a look at the Reserve Grand Champion Warbird from Airventure 2016; a Stinson L-1 “Vigilant”. This was done in Stewart's System including a process that gives the interior look of original white linen with out any signs of modern, green or pink fabric glue.

57Marty

#### Kyle Boatright

##### Well-Known Member
As to testimonies; the oldest covered aircraft using the Stewarts Systems are about 15 years old; many in Alaska. Take a look at the Reserve Grand Champion Warbird from Airventure 2016; a Stinson L-1 “Vigilant”. This was done in Stewart's System including a process that gives the interior look of original white linen with out any signs of modern, green or pink fabric glue.

57Marty
Here's the problem: Not a lot of us are gonna make it to Alaska to inspect an aircraft, and a 2016 restoration doesn't address longevity. This creates one of the challenges - without a number of older restorations using the product, a lot of people (OK, at least one - me) are reluctant to try it. So the low adoption rate becomes a self fulfiling prophecy...

#### Little Scrapper

##### Well-Known Member
HBA Supporter
Log Member
I'm gonna use it for sure. I like it a lot.

#### Dan Thomas

##### Well-Known Member
I'm gonna use it for sure. I like it a lot.
How does the overall cost stack up against Poly-Fiber?

#### Little Scrapper

##### Well-Known Member
HBA Supporter
Log Member
How does the overall cost stack up against Poly-Fiber?
Hi Dan.

I have not personally looked it up but I had 1 person tell me it comes out the same and 1 person tell me SS was a hair cheaper. Again, 2nd hand information but both guys are experienced and actually have done both systems.

I plan on using it just because I'd like to try something different. I don't like shiny airplanes, personally, so I'd probably put a flattening agent in it.

I decided to paint my fuselage a vintage Ford color called Washington Blue. Again, I'll put a flattening agent in it to kill.the gloss.

HBA Supporter
Log Member
Washington Blue.

#### 57Marty

##### Well-Known Member
At Airventure we had identified a number of aircraft in attendance that were finished in Stewarts Systems and had signs posted; that is the best venue to see many aircraft. As to adoption rate; that is increasing every day, more than you may think. Due to restrictions in many areas to solvent based paints, waterborn systems are becoming the only option for many builders. Here in California we are very close to seeing a ban on solvent based systems. In many California counties you can no longer buy oil based wood finishes; auto and aircraft paint are close behind.

The cost of covering for a Cub type aircraft is very competitive with solvent based systems. I have attached a jpeg of a complete list of current prices and all materials and needed to cover a Cub type aircraft. The jpeg was shot with my phone; quickest way to get the info to this discussion. I can email the list to anyone interested. This is a great discussion; thanks for the opportunity to answer some questions.

My background is that of a home builder just like many of you. I am a retired Industrial Arts teacher so I have taught many of the trades during my career. I started in an A&P program in college before switching to education.

Please let me know if you have any other questions. I'm currently developing new frames and other materials to use in workshops to show how easy and safe it is to use the Stewart System.

57Marty

#### Sprucemoose

##### Well-Known Member
I covered my Breezy (the covered bits anyway) with Stewarts and last winter, painted the whole thing with Stewarts. EcoPoly on the fabric parts and Ecocrylic on the exposed fuselage frame. I was talked into it by a neighbor who did his Kitfox with it. My hangar neighbor is painting his Pitts right now with it. So, come on down to 57C if you want to see it in various stages from still wet to sprayed a year ago. I was very impressed with it, and found almost none of the issues that others have reported...but... I took Stewarts recommendations on air guns, hoses, etc etc as gospel and set my system up exactly as they recommend, even if I had to spend a little money to do it. I also made some practice pieces and got my technique worked out on those- highly recommended. It does spray differently than anything else you've ever worked with, so practice and do it the way they tell you.

I agree with Marty on using the viscosity cup to calibrate, but 24 seconds is a bit slow for me. I had best results at 20-21 seconds and 3/4 turn open on the gun for the wet coats. This is all technique and preference, all the more reason to practice.

Like Kyle I wonder about longevity, but there is only one way to find out. As me again in 10 years...

#### StewartSystems

##### Member
To me the only advantage is the Ekoprime and the glue. The glue Im going to try with stits. Even though the top coat is waterborne, the spraying is as toxic as Aerothane. It is also one of the heavier top coats. Looks good though.
This is incorrect. Stewart Systems topcoats are no where near as toxic as solvent borne topcoats. If you like I can send you the SDS sheets for it. It is totally different chemistry. Only a charcoal respirator is needed when spraying Stewart Systems topcoats. Nothing is off gassing that is harmful, it is just important to keep overspray out of your lungs. Painting your lungs is never a good idea. Once the overspray is evacuated you can remove your mask. Also, you are incorrect about the weight of our coatings. On fabric, Stewart Systems is the lightest system on the market by a significant margin, with the exception of Oratex. Oratex is slightly lighter, but that is a completely different type of system with it's own pros and cons. Stewart Systems on Superflite 102 weighs .8 oz per square foot. The other systems we have weighed when removing them from aircraft are between 1.3 and 1.6 oz per square foot. That translates to a significant amount of weight on an entire aircraft. Probably in the 10-20 lb range with most GA aircraft. Our complete system adds .002" to bare fabric. Bare 102 is .005", completely finished is .007".

#### StewartSystems

##### Member
Stewart's Ekobond is the same thing as 3M Fastbond 30NF, which is cheaper. I used Fastbond when repairing the rib stitching on my Fisher.

Dana
EkoBond is not the same as Fastbond. EkoBond is manufactured in our facility in Ohio.

#### StewartSystems

##### Member
How does the overall cost stack up against Poly-Fiber?
The cost of Stewart Systems is a bit less than Poly Fiber. I'm not really sure about the price point of the other systems. I have heard Super Cub quotes with Poly Fiber at about $4500-5500. Stewart Systems products to cover a Super Cub will run about$3500 for materials, and if you include absolutely everything such as sand paper, irons, paint gun, paint strainers, etc... you will have about \$4300 in it. We have quotes available for most aircraft if you email us.

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