With Polyfiber, only the topcoat is catalyzed and only then if you are spraying Aerothane or Ranthane. Polyfiber offers another topcoat called Polytone which is not catalyzed and therefore a standard organic respirator is necessary. The Polytone is not very chemical resistant and has a duller sheen than the other two...While it does have its benefits (i.e. easier to repair, etc.) I think the fact that it is much less chemically resistant is a reason to opt for either the Aerothane or the Ranthane. I personally sprayed PPG Delfleet Evolution for my topcoat after learning this is what Aviat paints their Huskies with...If it is ok for a $200K certified airplane than it is good for my Kitfox. The finish is awesome and I am used to spraying this paint so there was no learning curve.

Again on the respirator, I think the fresh air system is a bit overkill for a one up project. I realize the catalyzed paints are very toxic if inhaled but a correctly fitted organic respirator will keep it out of you lungs for the short durations you will be in the paint booth. If you are doing this all day, every day then yes get a fresh air system, full face mask and complete body suit...for our home brewed jobs, this is overkill in my opinion.

Yes and No.... Polytone is Polyfibres dope. It is MEK based. You can do a quick google on the MSDS sheets for MEK and decide for yourself if you think a fresh air system is overkill. It is certainly less damaging to your body than a catalyzed system using a volatile carrier.
If I were using a polyfibre system I would use Polytone. But that's just as a matter of preference. It is only about 1000 times easier to repair (and look good) than Aerothane.
I can't really go along with the weekend warrior analogy. A hobbyair fresh air system is a lot cheaper than a set of lungs. Maybe it would be a good time to approach the local EAA chapter and see if they have one. If not maybe it's a good time for them to pony up and get one? This is about like saying one cigarette will not give you cancer, and it probably won't... But can you tell the guy dying which one it was?
All of these considerations where what I based my suggestion for the Stewarts Sytem on. All of these systems have their merits and their weaknesses... a guy just needs to pick the one that makes sence and one that he can apply well.
Take care, Rob

Rob wrote:.............. If I were using a polyfibre system I would use Polytone. But that's just as a matter of preference. It is only about 1000 times easier to repair (and look good) than Aerothane. ................

Easier to repair, plus I understand that it holds up better to flexing than aerothane. Check some of the threads, there was a tip about chilling polytone right before it goes in the spray gun- retards the drying I guess, resulting in a glossier finish.

Eric

Dokmow wrote:I believe this is true as long as you are not spraying Aerothane or any other polyurethane paint. They contain isocyanate which is very bad stuff. I believe the normal organic cartridge respirator is not effective. Someone correct me if I'm wrong, I am not a paint professional

That's my understanding--with the Stewart color coat being the exception--it's also a two-part ureathane, but because of the way it's system works (water borne) forced air isn't needed, just a good carbon canister filter.

Benton 9dec08

Dokmow wrote:

Darinh wrote:I just finished my Kitfox using the polyfiber system and you don't need a fresh air system except for the final color coats and then only if you feel it is necessary.

I believe this is true as long as you are not spraying Aerothane or any other polyurethane paint. They contain isocyanate which is very bad stuff. I believe the normal organic cartridge respirator is not effective. Someone correct me if I'm wrong, I am not a paint professional

Supplied air is the ONLY answer to any any thing that contain polyisocyanates!!!Spraying with out supplied air would be akin to snorting asbestos fibers. I have had two acquaintances impacted, one only had a little more than half of one lung the last time I seen him, and a young lady who was packing a portable oxygen bottle around waiting for a lung transplant, she was about 26 at the time. I have lost contact with them, but I know their prognosis was bleak. If you are ever unsure, read the MSDS, and error on the side of personal safety.

Quite right but akin to snorting asbestos fibers is a bit much...maybe spraying it without any respirator may be a similar activity...but polybrush and polyspray are not catalyzed and contain no isocyanates poly or otherwise. You only need the supplied air system for the color coats (except polytone) that are catalyzed and use an isocyanate catalysts. The other coats an organic respirator is plenty sufficient...Polyfiber even will tell you this and does in the manual. Rob mentioned these other coats are MEK based and they are so if you feel better about the fresh air system with this, then get it...it is overkill though IMHO. I am still walking and haven't lost a lung or carry an oxygen bottle...I wonder how many people would tell you to have to use a supplied air system and then go light up a Marlboro.

Darinh wrote:Quite right but akin to snorting asbestos fibers is a bit much...maybe spraying it without any respirator may be a similar activity...but polybrush and polyspray are not catalyzed and contain no isocyanates poly or otherwise. You only need the supplied air system for the color coats (except polytone) that are catalyzed and use an isocyanate catalysts. The other coats an organic respirator is plenty sufficient...Polyfiber even will tell you this and does in the manual. Rob mentioned these other coats are MEK based and they are so if you feel better about the fresh air system with this, then get it...it is overkill though IMHO. I am still walking and haven't lost a lung or carry an oxygen bottle...I wonder how many people would tell you to have to use a supplied air system and then go light up a Marlboro.

I'm not attacking the Poly-Fiber system, my point was IF any epoxy compound had poly-isocyanates as an ingredient you must use supplied air! This is going to date me, but when they used synthetic enamel to paint cars there was a hardener the could added to strengthen the paint and make it shinier. That hardener had poly-isocyanate in it. Some fiberglass compounds have it as well, It is my opinion that if you have no idea what may or may not be in the epoxy, look in the MSDS. The young lady I spoke of had been painting with Emeron ( spelling? ) for about a year. The guy had been welding on a epoxy filler and was breathing the fumes. She went for over a year, he had ONE exposure. My neighbor who is a A&P and AI, said he uses supplied air with the Poly-Fiber because he doesn't like the smell. I myself am not bothered by it. I spoke up because one of the bits of advice was you could spray Arothane with out supplied air if you wanted to. I merely wanted to point out it can be life threating to spray some chemicals with out supplied air. I worked as a mechanic in a shop that did many brake jobs, I some times did as many as seven a day myself. And yes, I blew the drums, and backing plates off with an air gun!!
(As did the other brake mechanic.) Yes I did, but there is no way I would tell some one new, to do the same thing with out touching on what may happen to them. My only concern was to educate someone seeking information, not to rev any one up.

I agree and my first post said that supplied air respirator should be used with any of the catalyzed paints...the undercoats it is not necessary but an organic respirator should definitely be used. Having said this, I did not use a supplied air system with my catalyzed paints...I did use a well fitted, full-face organic respirator and changed the carbon filters often. I just feel that the level of exposure you will get while painting an experimental aircraft is extremely minor and if your organic respirator is fitted well and you change the filters often, I think your risks are extremely small...My guess is that going to a nightclub and breathing second-hand smoke for 2 or 3 hours induces a much, much higher risk of respiratory problems than does the above stated situation.

I do agree though, if you don't feel comfortable...Spend the $450 on the Hobbyair system and forget about it...get the full-face option though because your skin and eyes will absorb the nasty chemicals rather quickly.

Thought I would update this thread. I ended up using Ceconite and recovering the wings and horizontal stab. Just about to the paint stage. It's coming along nicely.

Hi Avid,

Congrats! I bet all that apprehension you had about tearing off fabric is now replaced with peace of mind and a better insight in to your bird! Are you going to do the fuse while you have the wings off?

Take care, Rob

AAAHH, sniffing glue.

I have used several processes including Poly and Randolph.

If you can smell it then it ain't good for you.

My wife thinks I have done too many already and it has effected my personality but I have at least one more to do when I recover my Maule in the sort of near future.

It can be a lot of fun once you get past the apprehension of ripping off the old fabric.

I had a friend with a C140 that had a broken spar, when he asked me to look at it , I pulled out a big knife and cut a hole so I could see the spar. He about fainted. the spar was broken from a ground handling accident and it was plain to see. Still he could not believe that I took a knife to it.

I will look into some of the new processes. I can sniff glue anytime just by keeping a qt of Rando-fil out in the shop.

Last week I went to Graham Texas for a restoration seminar on Piper Supercubs and Shortwings. My tail feathers were sent for recover as part of the instructional portion of the seminar for Polyfiber. Myself and a fellow who is buying my father in laws cub covered the tailfeathers right back in the same method to match the rest of the airplane. It is a system that I was exposed to first. I have done extensive research for an upcoming recover of a Taylorcraft on Stewarts and luckily as part of this seminar we covered a PA18 elevator in Stewarts. The best thing of the whole process was the glue and the fact you can take your time with it and with a little heat rework it. The entire fabric work was performed in the maintenance area and not the refinishing booth as the glue and ecofiller(Primer) did not have any extreme smell. The first coat of gray ecofiller is brushed on with a foam brush. Dan Stewart sent Jason Gerard down from Washington to give this portion of the seminar and I can honestly say that this is the process I will be going with on the Taylorcraft. At the end it is so unusual to put your paint gun in the sink and not MEK.
Good Luck
John

I sprayed my RANS S-7 in Aerothane. I used an old electorlux canister vacuum with no bag. I plugged the hose into the exhaust end, extended the hose using pool cleaning hose into the spray booth and plugged it into my spray hood. I did put some filter material between the hose and the spray hood to stop any dust from entering. The first time I turned it on the hood flew off my head like a rocket..too much pressure. I drilled holes in the hose at the vacuum to vent most of the pressure and used that hook up to spray my plane. If your shop is attached to your house be sure to install a small exhaust fan in the shop that runs 24/7. It creates a negative pressure in the shop preventing fumes from seeping into the house.

The reason for needing a fresh air system and full suit with a catalyzed polyurethane is that the polyurethane requires an isocyanate in the catalyst. The key word there is "cyan", as in cyanide. Cyanide is attracted to moisture and guess what? We're mostly made up of moisture. The cyanide is going to come in through your soft tissues...eyes, ears, nose, lungs, etc... Cyanide doesn't smell much...so you're not going to smell it through your charcoal mask...but it's coming in. You may not feel the effects quickly...or maybe even at all. It's "cumulative", meaning that it's not going to leave your body, just build up. I used the example of a cup of water being filled by a spoon with my paint students... it may take a lot of spoonfulls to get the cup filled, but when it's full, just one part of a spoonfull and it'll run over...this is you getting seriously ill. Some people have more of a tolerance to it...some are "cups"...some are "thimbles" or even less. The isocyanate works just like electricity, in that it's going to follow the path of least resistance...... so when the waterborne polyurethanes are catalized, the isocyanate is happy there, and stays put. Most people don't realize it, but the most dangerous time by far for polyurethane paint is when you're mixing. At that point, the isocyanate is "searching" and here we are...lots of moisture, and oh so attractive!!
Polyfiber is a great system...I've used it for many years. Stewart's is an awesome system....and all that I'll use anymore. Their topcoat is by far the most flexible I've ever found!! I've got fabric samples that are more than 10 years old and you can still wad them up in a little ball and spread them back out, and not a crack anywhere. Really good stuff!
I'm at that point of getting close to the "cup running over", and just a whiff gets me pretty sick.... take it from someone that's there....it's not too cool.
Be safe!
John

Surprised to see this thread still alive. We are just about done covering my wings. Should be applying color this weekend.

hotrod180 wrote:As I recall, the Avid & Kitfox both use wooden ribs. What about PK screws as used on the Aeronca series wings? Not as pretty as rib stitching, but way quicker.

Eric

Curious why wooden ribs matter as far as covering and rib stitching goes?

I was reading thru this thread. Avid, I am curious, did you find any damage or areas that needed attention in your wings? Are you glad you recovered your wings?

Kurt

hardtailjohn wrote:Polyfiber is a great system...I've used it for many years. Stewart's is an awesome system....and all that I'll use anymore. Their topcoat is by far the most flexible I've ever found!! I've got fabric samples that are more than 10 years old and you can still wad them up in a little ball and spread them back out, and not a crack anywhere. Really good stuff!
Be safe!
John

Curious. I do fabric covering for a living and I mostly use Polyfiber, my favorite system. I've seen Stewart and seen both good and terrible results; flaking and peeling within a couple of years, heavy and brittle. I've never seen a Stewart covered airplane older than two years that looked good. I'm sure it's mostly use-error, but I'm not impressed. Especially considering the cost. I'm usually stick with Polyfiber and if people want a fancy shiny (heavy) top coat. I send them to the local paint shop for some Ranthane.

Even a busy 16 year old can do a good job recovering an old Pacer with Polyfiber. It repairs super easy too. It looks great years later. It is ridiculously toxic, though, and even though I had good ventilation and a respirator with plenty of cartridges, and I still felt bad at the end of a productive evening. It looks great, it's easy to get slick, and I hated it for the MEK.

I've also helped on using the Randolph finishes and they can still look fine after 5 years in the full Colorado desert sun, even with Razorback. They don't leave you wondering how many brain cells you had to sacrifice for the effort. I've also seen some AB-EX jobs that looked like there were problems with the Randolph.

Aerco wrote:

hardtailjohn wrote:Polyfiber is a great system...I've used it for many years. Stewart's is an awesome system....and all that I'll use anymore. Their topcoat is by far the most flexible I've ever found!! I've got fabric samples that are more than 10 years old and you can still wad them up in a little ball and spread them back out, and not a crack anywhere. Really good stuff!
Be safe!
John

Curious. I do fabric covering for a living and I mostly use Polyfiber, my favorite system. I've seen Stewart and seen both good and terrible results; flaking and peeling within a couple of years, heavy and brittle. I've never seen a Stewart covered airplane older than two years that looked good. I'm sure it's mostly use-error, but I'm not impressed. Especially considering the cost. I'm usually stick with Polyfiber and if people want a fancy shiny (heavy) top coat. I send them to the local paint shop for some Ranthane.

Well, I do it for a living too. Have for over 35 years. I've seen a few messed up Stewarts System jobs, but seen a whole lot more that were awesome!! I've never seen a heavy or brittle one. I've got samples that I shot in the 90's that you can still wad up into a little ball and flatten out with NO cracking...never seen ANY other system able to match that. Quite a few aircraft are out there flying and staying outside that are 20+ years old. As far as heavy, I'm not sure where you're getting that. It's one of the lightest systems out there, by a substantial margin. As far as cost, it's actually less when you factor in shipping and the fact that you're not buying any thinners or anything like that. Not to mention the safety factor of it all, which is why I got involved with it in 96. I had the choice of quitting or finding another way to cover....or being dead. I think you're confusing Stewarts with the old Blue River system...don't feel bad, many make that mistake, but the 2 aren't related.
John