Corrosion Treatment

[GAD]

Several of the Cessna 170’s that I have seen for sale have had the inside of the tail cone (tunnel) sprayed with some form of corrosion treatment. George eluded to a couple of products “chromate or epoxy polyamide” during the discussion on “factors when buying a 170.” I was wondering how many of you have your plane treated and if it has been or needs to be documented. I am wondering if I will run into any issues during an inspection if there is no mention of it in the logs. Also, what products are approved for use? Are any of them black and tar like in appearance?

Thanks, Greg

[Bruce Fenstermacher]

My plane was treated about 15 years ago with ACF-15 (I think that's the product). The inside of the tail cone looks like it has a light coating of blackish tar.

As corrosion treatment is maintenance it should be logged in the log books. Whether it is or not could be indicative of the type of maintenance records your looking at.

Corrosion treatments are preventive maintenance but some times it's to prevent the return or corrosion removed. I'd look a little harder at the aircraft for corrosion if it was treated I suppose.

If I found nothing else wrong with the logs or maintenance the fact the treatment isn't logged wouldn't be a show stopper for me.

[sphillips]

I think you are referring to zinc chromate which is an aluminum primer and protectant. One of the aftermarket products available for corrosion control is ACF 50. Check with your mechanic.

[Bill Hart]

ACF-50 is in fact a great corrosion inhibiter that I highly recommend. When applied it forms a very light film and gets in very crack and crevasse. Most people who use it in the south east use it bi-annually or annually. I treat mine annually. It should be logged as any other maintenance because to do it right you have to remove several panels and the cowling as well as the interior.
I have seen this blackish tar but only under the cabin floor and cabin walls used as a sound proofing not necessarily as a corrosion inhibiter, but it might not be the same thing.

[CBogle]

I had my aircraft treated at the last annual as we could see the beginning of some minor corrosion in the tail section. The cost to treat the entire aircraft with ACF-50 was $250.

ACF-50 is available and I've been thinking of trying to find a way to spray it in there myself. I'm not familiar with spray painting equipment, but, I would think I could hook some paint applicator up to my compressor and with a long wand with a nossel at the end, create a spray that atomizes ACF-50. The equipment being used by the person I paid the $250 to didn't seem too exotic.

If anyone has some suggestions as to what type of low-cost spray unit I should try, and where on-line to purchase same, I would appreciate the input.

Thanks,

Curt

[thammer]

I saw the spray gear in one of the catologs, Chief, WagAero, Spruce or Univair, can't remember which. You basically have a selection of several different length wands with different spray pattern heads. Straight ones and ones with bends at the end to get into spots a straight one can't reach. The tank was one of those tanks like you'd use to spray pesticides or lawn chemicals. Fill it up so far with ACF-50 or Corrosion-X and put the hand plunger pump on it and pump up the pressure. Spray away. Equipping yourself to do it would probably cost more than your $250 annual expense but thereafter you'd only need to buy the ACF-50.

[N2255D]

try http://www.jcwhitney.com/ and search on rust proofing spray kit.

[GAHorn]

Well, my opinion of this subject is thus:
Any corrosion treatment of the airplane is a maintenance item and should be logged (included in the maintenance records of the aircraft.)
ACF-50 is a particular product/process, similar to others in the industry. ( BoeShield is another produce which enjoys an excellent reputation.)
ACF-50 is a proprietary product which has gone to the expene of gaining FAA approval, therefore it's most likely the best source for usch treatements.

Treatment of aircraft interior surfaces have drawbacks:
What procuct is to be used? (while WD40 was used extensively in years past, such "coaching" will not meet the JAA standared of operations.

[cpolsley]

I treated my airplane about 10 years ago. I used LPS 3 and am very happy with. I plan to treat it again this year. I choose LPS 3 because it was cheaper than the ACF 50 and the company I work for use it on our fleet of DC-9's DC-8's etc. LPS 3 can be purchased in 1 gallon jugs which is what it took to treat the entire airplane. I used a venturi type engine sprayer to apply mine. I picked up a long clear plastic flexable tube, which I bought at the local hardware, to attach between the LPS container and the sprayer. I then borrowed my wifes clothes line pole and taped sprayer to it so I could run it through the wing tip clear through the wing to the fuel tank. The LPS seeped through every nook and cranny for the next 3 or 4 years so I know it penetrated well. Next time I treat it I plan to heat the LPS, not hot, but enough to make it flow better. Definitely apply it during the summer months. Any kind of treatment product you can put in it is better than nothing at all. Another area that should be treated is the wing carry through spars. These can be sprayed using LPS 3 spray can or whatever product you choose by using the little red flexable nozzle and spraying it up through the holes in the bottom of the spars. You can manipulate the nozzle so it goes in all directions.

[KMac]

My plane has the black "tar" coating in the belly and sides of the fuselage. Like Bill said, I thought it was for sound proofing.

[bradbrady]

Curt,
Boy if you are getting a GOOD treatment for 250.00 don't change! I use the Corrosion-X system, The wands are specialy developed to create a FOG and not actually spray (as in a paint application) To put it in perspective the costs for me to do a 170 would be---

Product: (including my investment in the equiptment) 100.00
Disasambly, spraying, and reasambly of aircraft, 5hrs @ 60.00 shop rate= 300.00 total= 400.00 Anything under that your getting a deal!!!!

BTW unless you live with salt spray soaking your aircraft, every two to three years is enough to treat your aircraft. (IMO)
brad

[steve grewing]

Mine had some of the dark brown material in the belly. Looked like very old Black Bear par-al-ketone. Cleaned up easily though messy with MEK. After final assembly I treated the entire plane with Corrosion-X. Every hole accessed including belly, door posts and door surround, etc. was sprayed with a fogger. It dripped out the wings for months, still have some to wipe off after warm weather flight after over two years. I bought a gallon since I had no idea how much would be required. I can get two+ more applications out of the jug. I plan on reapplying next summer during August annual. Careful application with good equipment could probably be done using only one quart. It certainly flows out well. I placed a small spot on a vertical section of steel structure in my hangar. Over a couple days it was a large as a dinner plate. I certainly would not apply it if I was considering painting the plane within several years.
Steve

[c170b53]

I used ACF-50 in a spray can, seemed to flow out well and got into the seams. It's still leaking out and making a mess of the hangar floor a year later.

[WWhunter]

Check Harbor Freight tools and Northern tools. I think both of these places sell the fogging wands. I did my 172 a couple of years ago and it is pretty easy...just takes time disassembling everything. I used Corrosion X and like the others say...it seeped out for a LONG time.

Keith

[N2865C]

ACF-50 has on-line training videos. The files are BIG and take a long time to download. http://www.corrosion-control.com/acf50.html