I got tired of the typical exhaust flange gaskets.  Especially, since I have made my stainless system.  The typical flange gaskets are steel and whatever gasket material.  They end up rusting away and crumbling. 

 

This is what I did:

On a flat surface,

piece of aluminum foil.

Piece of fiberglass repair cloth.

Ultra copper RTV, worked into the glass.

Piece of fiberglass repair cloth.

Ultra copper RTV, worked into the glass.

Piece of fiberglass repair cloth.

Piece of aluminum foil.

Steel plate and weight on the stack for 24 hours.

 

Cut out the holes and edges.

 

Installed in exhaust system.

 

So far, it's holding up, no leaks.

 

 

I'd be interested to see your results after a few months,  I've had my share of faulty aftermarket gaskets that are complete garbage straight out of the box.

Has anyone tried the sheets of generic gasket material, Mr Gasket, Felpro , ect?

I bought a sheet of felpro exhaust gasket material from autozone. Its tan in color and a little difficult to cut. but with some tin snips it can be done. it worked very well for me. and its not that expensive for a pretty big sheet. 

Edited April 8, 201510 yr by SoobDood05

I just use high temp silicone.

Works a treat - just make sure you clean both surfaces with a grease and wax remover before installing the exhaust with the silicone.  You don't need much!

Under torque bolts, leave over night if you can then torque bolts properly.  If you can't leave it over night idle the engine for a minute to get some heat into the exhaust.  Let cool then torque.

Cheers

Bennie

I usually use the aftermarket gaskets and smear them with high temp RTV (Orange) gasket maker. It works for me just fine. It also helps if you have good studs to bolt your exhaust.

Ive been experamenting with copper gaskets i made my exhaust out of 2 layers of copper and coated them with copper spray they have only been on the car for a week or so but are holding the store bought gasket only lasted a few days

 

 

 

 

 

Are you guys having issues with OEM SUbaru gaskets - they work fairly well so far for me. It is crazy how much exhaust gaskets deterioriate.

what is the deal with the exhaust manifold gaskets?  I can't seem to get them to last more than a day before they start leaking...

 

the only think I can figure is that the size of  the exhaust port and the size of the flange on the pipe are not matched very well.  It seems the ports are smaller that the pipe flange...they have a little over lap but not much so I'm not getting a solid seal....

 

is it possible the Y pipe is not correct and is off another model Subie? 

Do you put them on "dry"?

@DaveT

I like the 'sandwich' idea. You were able to use easily available household supplies and it sounds like it will probably work.

 

@Frep420

I like your copper gasket work! If you can get them to seal initially, then they will probably last for years. Way to go What are you using for copper sheet? You must have a bit of it available already as it ain't cheap.

Edited April 16, 201510 yr by Crazyeights

Do you put them on "dry"?

+ 1 on this ??

 

 

Are you guys having issues with OEM SUbaru gaskets - they work fairly well so far for me. It is crazy how much exhaust gaskets deterioriate.

I guess I better be checking mine again, I finally got them done with the studs giving me HELL and then the gaskets were a PITA also, got  them to seal though I think.

My landloard owns a sheetmetel shop and he dose alot of copper work he lets me play with his scraps i use alot of it in art pieces mostly custom order stuff when i sell a piece i kick down for the copper it ends up being more than what he gets from recycling it so he is happy there is no way i couldent aford to buy it new the best part is there reusable they dont where out reaniel them then recoat with copper gasket spray no more buying gaskets im using them for both my intake and exhaust the ttick is to aniel them so there nice and soft i coat them with the copper spray for alittle extra seal

"is it possible the Y pipe is not correct and is off another model Subie? "

 

I actually went through a bunch of bs with these once due to a missing asv spacer i didnt know it right away until doing several gasket replacements. Since ive seen them with none, one or both spacers i didnt think anything of it. In the end it was totally solved by extending a pipe and using gaskets purchaced from car quest for another vehicle. Iirc it was something wacky like a ford 223 or amc 232. They were a thin metal outer with an asbestosy oreo filling. Im following this thread with interest davet always has a solution.

What started it for me - the flanges on my custom real stainless system are 2".  Even the nice gaskets I got from the tuner parts place to go with the stainless flanges, are made with regular steel.  Stupid.  The one on the system I had to remove to swap transmissions crumbled when I took it apart.  Copper might work for that one, if everything is dead flat.  I thought about it for a few days, and came up with the fibreglass reenforced RTV gasket idea.  I actually made some for my Dynahoe a couple years back, because it is not something you just walk into a store and get parts for. 

 

I think I'll try making a pair for the Y pipe to engine next.  I've got at least one leaking a little again.  I've never had consistent luck with those no matter where I got them.   Then, when I have a set not leaking, something comes up, I have to remove the Y pipe, and back to zero.

 

I also don't like the idea of using steel in any part of the gasket, since when it rusts up, it expands.  Probably contributes to the exhaust studs getting stripped out.

How well my fibreglass + RTV gaskets survive pretty much hinges on if the RTV can withstand the temperature.  With the aluminum face surfaces, the should be reuseable.