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infinitenexus
infinitenexus HalfDork
6/3/20 3:36 p.m.

I have a slight exhaust leak where my two part header bolts together on my challenge civic. The cheapo Chinese gaskets were garbage so I picked up a sheet of mr gasket exhaust gasket material to cut a better one. So it just got here in the mail and uhhh...  apparently it’s a sheet of cardboard?  Feels like cardboard, bends like it, tears like it. Am I missing something here or is this a great way to start a car fire?  Or is there some cardboard - like gasket material that’s legit?

 

infinitenexus
infinitenexus HalfDork
6/3/20 3:38 p.m.

Yeah I’m holding it right now and both my wife and I agree that this is a sheet of heavy duty cardboard. That seems extremely unsafe. 

Streetwiseguy
Streetwiseguy MegaDork
6/3/20 3:39 p.m.

I seldom use gaskets in exhaust, if the flanges are remotely flat.  Red high temp silicone.  Well, that's a bit of a lie.  If it comes out of a box with the automobile manufacturers logo, I use them.  Aftermarket?  Not unless it's some sort of high priced copper magic thing.

infinitenexus
infinitenexus HalfDork
6/3/20 3:45 p.m.
Streetwiseguy said:

I seldom use gaskets in exhaust, if the flanges are remotely flat.  Red high temp silicone.  Well, that's a bit of a lie.  If it comes out of a box with the automobile manufacturers logo, I use them.  Aftermarket?  Not unless it's some sort of high priced copper magic thing.

Thanks. I’m gonna go pick up some of that. Flanges are pretty flat, just a slight curve in one. I guess just enough that cranking the bolts down won’t squish a cheap metal gasket into shape. Red silicone it is. 

wvumtnbkr
wvumtnbkr UberDork
6/3/20 3:45 p.m.

I always use full soft aluminum and cut out the shape I need.  Works awesome.

(Jesse) Ransom
(Jesse) Ransom UltimaDork
6/3/20 3:47 p.m.

The exhaust gaskets I always got for the M10 in my BMW 2002 were bound with some sheet steel folded over the edge, but the bulk of the thickness was made up of a grey material which was apart from the unusual (for cardboard) color very cardboardy. The cardboardy stuff even made up the heat shield flange to protect the spark plug boots on the nicer versions.

I wouldn't hesitate. There are a lot of fibers that don't come from trees but which could be bound/compressed into something very much like cardboard, and I doubt Mr Gasket's lawyers would let them sell kindling as a gasket for long.

No Time
No Time Dork
6/3/20 3:52 p.m.

Does it burn?

ShawnG
ShawnG UltimaDork
6/3/20 3:54 p.m.

What streetwise guy said.

We quit using exhaust manifold gaskets years ago and have had way less problems.

codrus (Forum Supporter)
codrus (Forum Supporter) UberDork
6/3/20 4:06 p.m.
No Time said:

Does it burn?

It's probably asbestos. :)

 

Dave M (Forum Supporter)
Dave M (Forum Supporter) HalfDork
6/3/20 4:07 p.m.

Thats must be special asbestos cardboard. Good for the lungs - builds character.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
6/3/20 4:20 p.m.

They work for manifold gaskets because the cylinder head is a heat sink.  Kind of like how you can hold a metal bar in a paper sling and put a lighter under it without the paper igniting.

 

They do not work so well for flange gaskets downstream.  They do work, on cars that just putt around.  Nothing where you lean on it for any length of time.

SkinnyG (Forum Supporter)
SkinnyG (Forum Supporter) UberDork
6/3/20 7:11 p.m.

I've often felt "Mr.Gasket" is a misnomer.  I have not had good luck with any of their gaskets. Could just be me.....

infinitenexus
infinitenexus HalfDork
6/3/20 7:43 p.m.

Thank you for all the replies, everyone. I picked up some high temperature silicone gasket material and applied a hefty dose on there and lightly closed up the gaps. Per the instructions, tomorrow after 24 hours I’ll tighten up the bolts. Fingers crossed 

Patrick (Forum Supporter)
Patrick (Forum Supporter) MegaDork
6/3/20 8:06 p.m.

Cheap headers used to ship with gaskets made of that and they would blow out a few hundred miles later.  

jfryjfry (Forum Supporter)
jfryjfry (Forum Supporter) Dork
6/4/20 1:06 a.m.

I got a set of percys header gaskets for a 351w and so far they are fantastic.  I have no experience with no gaskets but sounds like that's a good way to go if everything is flat enough. 

A 401 CJ
A 401 CJ Dork
6/4/20 6:20 a.m.

A few years ago I replaced a rusty cheapo header with a not rusty cheapo header.  The new one wouldn’t seal.  I boned up on the internet.  Learned a few things: some of the higher quality manufacturers actually say to use sealant and to skip gaskets all together.  Also, it’s much easier to make it seal if you cut the flange.  Having that one continuous piece across all four pipes can sometimes be a challenge.  Consider sawing it in two.  Or four if you have to.

jimbbski
jimbbski SuperDork
6/4/20 8:38 a.m.

Years ago I needed some exhaust gasket material since the need was on a engine that no one offered any for.  I purchased some material that had a wallfle like layer of steel embedded in some "cardboard" like material.  It was a bitch to cut but the stuff held up fine. The metal in the gasket is the key.  it keeps the gasket together and from blowing out as the cardboard only material would most likely would do.

SkinnyG (Forum Supporter)
SkinnyG (Forum Supporter) UberDork
6/4/20 9:34 a.m.

I did not have success with Percy's header gasket, but it might have been the header's fault, not Percy's.

I have had grand success with Remflex gaskets - even collector gaskets.

I have not tried exhaust silicone yet, but everyone who has, raves about it.

ShinnyGroove (Forum Supporter)
ShinnyGroove (Forum Supporter) Reader
6/4/20 9:42 a.m.

The best thing I've found is the Permatex high-temp copper spray gasket.  Easy to use, withstands heat, will fill small gaps.

https://www.amazon.com/Permatex-80697-Gasket-Hi-Temp-Adhesive/dp/B000HBNUDQ/ref=sr_1_3?dchild=1&keywords=CRC+copper+gasket+spray&qid=1591281684&sr=8-3

mw
mw Dork
6/4/20 9:44 a.m.

I used to work at a place that sold specialty paper products (often for use in electric motors). There were many materials that looked a lot like regular cardboard that contained thing like nomex etc. I have no idea why that stuff in your picture  is, but just because something looks like cardboard, doesn't mean it's regular cardboard 

infinitenexus
infinitenexus HalfDork
6/4/20 9:52 a.m.
SkinnyG (Forum Supporter) said:

I did not have success with Percy's header gasket, but it might have been the header's fault, not Percy's.

I have had grand success with Remflex gaskets - even collector gaskets.

I have not tried exhaust silicone yet, but everyone who has, raves about it.

Yeah after reading everyone praising it, I picked up a tube of the exhaust silicone.  In about 5 more hours I'm going to go outside and tighten the header bolts all the way, jump start it, and check for leaks.

iceracer
iceracer MegaDork
6/4/20 12:21 p.m.

When I installed the cat-back on my ZX2SR it came with a "flexible" gasket.  It was the wrong size so I got one from Advance  Auto .

Worked fine.Never leaked.

May have been cooler temps than nearer the engine.

SVreX (Forum Supporter)
SVreX (Forum Supporter) MegaDork
6/4/20 12:51 p.m.

How come no flamethrower field testing? You know... for science!

mtn (Forum Supporter)
mtn (Forum Supporter) MegaDork
6/4/20 12:56 p.m.
SVreX (Forum Supporter) said:

How come no flamethrower field testing? You know... for science!

Yes!

 

Not helpful to the gasket conversation, but a lot of cardboard is not the flammable risk you think it is. A friend of mine worked for the largest "corrugated paper" company in the country... Apparently they get mad if you call it cardboard - but he went into how there are about 100 different kinds of cardboard for different purposes. (It could have been 5 different kinds of cardboard... The conversation was very boring, because it was about cardboard). 

wspohn
wspohn Dork
6/4/20 1:19 p.m.

Problem with no gasket is that flanges can deform under heat and start leaking, if not immediately, then after hundreds or thousands of heating/cooling cycles.  High heat gasket goo is fine, but can blow out and really needs some sort of substrate to hold it in place.  The old style sheets of exhaust gasket material used to be some sort of asbestos with a perforated metal carrier.  It has been non-asbestos for a long time, but none I have seen look like cardboard.

Agree with the stick it in a flame test.

Back in the old days, real men didn't need gaskets.  Some of the prewar MG race cars did without head gaskets. All it took was someone to spend hours with a surface plate with valve grinding paste lapping both block and head surfaces. And they got to do it all over again if you overheated the engine and had enough deformation to start leaking.

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