The International Cessna 170 Association

Wondering if anyone has a secret formula for removing old gasket material from vrs surfaces? I know all about scraping it with various items, but am trying to clean the area of the tack drive housing and there isn't much room to do much in that area. Would B-12 Carb. cleaner remove the left over stuff? Is any of this "gasket remover" sold in auto supply shops any good for this purpose? Hate to have to end up removing one or both mags to get in there.

Have several cans of "Gasket Remover" in the shop and it seems to work well. Will get a brand name tomorrow.

While it is too late to help this time here's a technique I recently used.

I was replacing the old style rocker cover gaskets with new silicone ones.
Take a heat gun (I used my Monokote gun from R/C model building) and throughly heat the gasket and the area around it. They will come right off
with very little material to clean off. Russ Farris

Permatex is a brand of aerosol gasket remover I have used with great success. But keep it from splashing on paint, plastic, or windshields!

What I have in the shop is Loctite Chisel Gasket Remover (does not contain methylene chloride)

Frank,
This should light a fire under this thread.

Are you replacing the entire gasket, that is the generator and the tach drive?

John, in response to your question, yes, I am replacing the entire gasket. My oil leak appears (from info developed via dye in the oil/black light) to be coming from near the left side of the tach drive housing by the lower left hand stud. The gasket has a slight concave indention which would possibly indicate some old gasket material still on the accessory case at the mating location. I have removed a fair amount of old gasket material in a very difficult/ hard to access area, but there is still dark area's showing on the accessory case so I am assuming I still have some old material there even though one can't feel it. I have a can of automotive gasket remover (spray) and a can of B-12 (or similiar) carb. cleaner and plan to use one or both to assist in cleaning any residual material off the mounting surface plus using a single edge razor. Hopefully doing so will render this oil leak fixed!

And I hope you'll paint the surfaces of both the case and the accy-case with Permatex #2 prior to reassembly. (And that you have absolutely determined, with a magnifying glass, that the tach drive housing is not cracked, expecially at the stud holes. heh-heh)
Is the stud secure within it's threaded hole?

Yea George I don't believe there is a crack on this one. My IA ck'd it with a 10 X glass & feels it is OK and the Garlock is OK also. Regarding the material on the gasket itself. I suspect that Permatex may be the ultimate culprit on this as most I have ever used (Permatex) is very difficult to remove. Not sure if the aviation Permatex is easier to remove or not. I do have a can of it that has never been opened. I usually use a thin coating of Titeseal on both sides of the gasket. One experienced mechanic at GPM is very strong in his opinion that this area was never intended to have any product put on it other than the gasket, but I perfer to put something on the gasket hoping to eliminate this ongoing leak. I may have to be committed if this next go round doesn't remedy the problem

In the course of reading old posts I came across this post on gasket removal and have to share something I discovered not long ago. I was removing corrosion from around rivets on the wing when ran across the 3M Scotch-Brite Radial Bristle Disc. Theses things are fantastic! You can remove paint and corrosion from the area immediately surrounding a rivet without damaging the rivet or skin. I was amazed! I’d tried everything I could think of including media blasting with a spot blaster. That worked but at a cost, it is nasty, very uncomfortable noisy and the media ends up everywhere. There seemed no magic fix until I found theses things. I use them on my dremel and only spend seconds per rivet. They DO NOT harm thin gauge aluminum and they can be used for gasket removal as well without eroding the sealing surface. I stack them and use two at a time. Also available is the 3M Roloc Bristle Disc White 3" Diameter Grade 120 Grit (white denotes 120 grit in both products) for larger areas. I get the smaller ones from Amazon and the 3” ones at my local automotive paint store. The larger ones last a very long time and are only about $10 each. Try them, you won’t be disappointed.

https://www.amazon.com/Scotch-Brite-Rad ... B0741F282L

MEK?

Aeroplane wrote: I was removing corrosion from around rivets on the wing when ran across the 3M Scotch-Brite Radial Bristle Disc.

What grit disc are you using? 120?

I see they also have different sizes appropriate for a Dremel of 3/4" and 9/16" These sizes come in higher (finer) grit to include Pumic, M1 and Polish

Yes Bruce, I use 120 grit, it works great. It’s another one of those products I wish I’d discovered long ago!