Aircraft finishing systems (AFS)
 

Has anyone used the AFS waterborne one part primer??
If you have how has it held up over time ? I am wanting to start building in the next few months and am trying to figure out the BIG primer questions as soon as possible.. I will be building in the attached garage and I don't want to drive the wife and kid out of town with the fumes..
Any help would be great.
Chris
Bonney Lake, WA

3 years of sitting in the hangar (not flying yet) -- no visible degradation. Holding up well to the abuse of assembly and repeated handling (ie empennage). Andy Karmy has probably been flying with it the longest, you might contact him if he doesn't see this thread.

Toughness is proportional to the thickness of the coat. Thin coat = can scratch off with fingernail. Thick coat == fairly resilient, not "hard" like an enamel, but will still protect against abuse. A medium buildup (metal slightly visible) seems tough enough for most purposes.

It still makes fumes, though less than the alternatives. I cannot recommend spraying it in an attached garage w/o ventilation.

I used it early on, then switched to a self-etching auto primer I could obtain locally. It's been a few years ago but I recall that it was slow to dry...like overnight slow. It seemed to require multiple thin coats. Orange peel was common but all that might have been my technique or lack thereof. It requires etching (but not alodining), so there is an additional step beyond a self etching primer. It smelled about as strongly as other paints, I thought. It dries hard but seems thicker than the primer I'm using now. It is advertised as a seal coat as well as a primer, as I recall, so it may provide more protection from corrosion than auto primer, but I'm just guessing. I might try it again in the future. BTW, I sealed up the seams on the forced air furnace in my shop with a roll of aluminum tape and that cut down the smell in the house a bunch. Almost undetecable now.

Chris,

I have the same report as Paul. I used AFS on the empennage and wings, but it's just been in storage since. The paint has more of an ammonia smell than the spray can stuff I've been using lately (SW GBP-988).

Andy flies out of Auburn, so you can probably even check out his plane if you ask him. Or I think he shows up to the Puyallup EAA meetings still. That's a good RV chapter, by the way.

Dave

I used it per Andy Karmy's website and would use it again. I sprayed two light coats, dried enough for riveting in a couple hours, cleanup with water, and very tough. Also used AFS topcoat paint for my interior. Wish I had used it on the exterior. :rolleyes:

AFS Primer
 

I've been using it in my garage for over a year and have been quite satisfied. Ive been using the cheap spray gun Vans sells - good enough for priming internal structural stuff (I'm not priming most alclad parts). Be sure to use the etch prior to priming - the fumes from that are much worse than the paint. It does take multiple coats (as specified in the directions). I found it dries to the touch pretty quick, but requires overnight for full cure (I've found much the same using the Sherwin Williams self-etching primer as well). When dry it is very tough - I often primed before dimpling and the primer survives dimpling just fine. I use the SW primer for quick small stuff (not worth the hassle of using & cleaning the spray gun).

I also used some of their finish paint for the first time last weekend - painting the inside of my tipup frame prior to installing the stiffening kit. I have a Lowes HVLP spray gun for that. I was pleasantly surprised with the results. I didn't set up a spray booth, but used a fan nearby to try to minimize overspray settling (for both primer and finish). The finish definitely has the 'wet look' when dry, and it takes a while to dry - 2 hrs before dry to the touch (I don't know how long auto paints take). The smell of the finish paint is stronger than the primer.

I just bought some
 

I just purchased a gallon of their primer and will use it on my wing kit.

I used Marhyde Self Etching primer on the emp mostly from the gallon can but some from the spray cans. It does not hold up well to rivets under the shop head at the dimple. Most of the time it cracks off all around the shop head here.

I hope the AFS does better in that regard.

Primer
 

I used Marhyde with excellent results. No cracking, splintering, etc. NAPA sells a similar product that others are having good results with also. A company called Smart Shoppers has good prices on the web for Marhyde by the case. Dimpling might be better done prior to priming.

Ron Kostus N567RK - reserved
Finish kit, etc.

I have been using AFS for three years, now. I did most of the empennage with SW 988 and enamal topcoat. I did some of the empennage, all of the wings and all of my fuselage with AFS. The AFS primer is a lot tougher than the enamal, but probably not as tough as an epoxy. It is possible to scratch it if you try, but I have never seen a scratch on parts that have been shuffled around in the garage, uh, I mean aircraft factory. After a year, yoiu can still remove the AFS with MEK, but it holds up pretty well to Lacquer Thinner.

There are a number of advantages with the the AFS primer.

• you can just pour the left over paint back into the bottle (it comes in a plastic bottle with a screw-on top).
• clean-up is with water, but if it starts to dry, lacquer thinner will take it right off, as long as it is not too dry. If it is really dry, MEK will take it off.
• it is thinned with water (I use it straight out of the bottle).
• the fumes are not as bad as most other paints. There is a strong oder of ammonia, but not nearly as bad (or good?) as the SW988.
• unlike the self-etching primers, it does not need to be topcoated in order to provide protection.

I have used the AFS Polyurethane topcoat, also, and I am very happy with the results. I painted the HS on my empennage, and I still need to perfect my technique, but the results were pretty good for a first attempt. I will be doing the whole airplane myself, using AFS.

Tracy.

I have used the AFS primer on my empennage and have been fairly well pleased. Actually, I was very pleased with how my rudder skins came out. But, then again, I guess that is what practice will do for you. :-)

I really only see two down sides to using AFS. 1) you need to etch the parts. The AFS etch is water based, so once the etch is done and the part is rinsed, the part must be dry before priming. This obviously isn't very hard to do, but it is additional process time. 2) Cure time. If you apply a thinner coat, it will cure fairly fast, though I prefer to let it cure overnight. However, if you go heavy, it may take a long time. As in 3 days long. So, the lesson here is: 3 light coats like the AFS guys say.

The upshot is that it is pretty tough once it is cured. The only thing that has taken it off was a beating with the flush rivet set while riveting. Oops. :-) Otherwise, it has withstood reassembly and the day-to-day shuffling around the shop with no problems. It has also stood up to the occasional stray bucking bar very well. I do cheat and tape the edges of my bucking bars for just this sort of event, so the results may have been different if I didn't use the tape.

Personally, I haven't found the odor to be particuarly foul. Keep in mind, though, that I have done all of my priming outside. I would recommend you do the same.

If you do decide to give it a try, do be sure to buy the Dupont viscosity cup and thin the primer down to 18 seconds. I have found this to be important for obtaining a nice smooth finish. Well, that and filtering like the instructions say. :-)

All in all, it looks great once it's applied. I expect will continue to use it for the rest of the build.

Cheers,
Robert