Copper Gaskets

[Lextreme II]

I am trying to make some gaskets for the header/cat interface. Since I have a turbo the flange design is little different and the oem gasket would not work. I made a gasket from the typical paper type and it got burned. I need to do two things to make it work. Get a high temp paper and make a gasket out of it or I was thinking using copper sheet. There are a lot of copper sheet used by artist and they are pretty cheap from ebay. I just got two sheets. They are 6" x 8". Plenty for the one or two cat flange gasket. What do u think?

 

[steveo]

Typically a copper gasket is only faced with copper. The material inside is soft enough to be crushed to shape and is heat tolerant. Something like fiberglass matt used for motorcycle exhaust could be cut to shape and sandwiched between the sheets of copper. Make sure that the outer sheets of copper are folded over the edges or riveted together (as done on the multi-layer steel gaskets). The only draw back to this type of gasket is that when it takes a shape it won't be easy to tre-use it since it is intended to crush to seal. The materials are cheap enough and the construction should be easy enough to do a few one offs so that you have spares.

 

[200sx-v8]

Use graphite. I have used that for ages on turbo\exhaust gaskets. Works very well.

 

[Lextreme II]

Where would i find graphite material.... and how hard it is to make a gasket out of it. For copper, i can cut and grind. Graphite works the same too?

 

[200sx-v8]

Graphite is very soft to cut in. I just cut out the gasket with a sharp knife.

I'm getting the material from a local machine workshop that works with laser and water cutting. The are specialized in making flanges.

Found this after a quick google search on the subject. http://www.china-gasketmaterial.com/

 

[TundraEddie]

Copper should work,I've seen exhaust manifold and 3-bolt header flange gaskets made of copper. I'd start with copper sheet that's a little thicker than the original gaskets.

 

[stevechumo]

Paper type gasket will be burned and become ash. I had that problem before with turbo flanges. The paper might be used with regular exhaust flanges only. You can go to Pepboys. They have many different grilled steel flange gasket sizes to choose from. Copper gasket should work fine. Or you can try galvanized sheet. I'm not sure what it's actually called, but it's at Home Depot near the hardware section. It looks like stainless steel sheet. I used it as turbo heat shield and it worked great. It doesn't absorb the heat much. I had a hard time to cut it as a gasket without wrinkling it so I couldn't make it as gasket.

 

[Lextreme II]

Or you can try galvanized sheet. I'm not sure what it's actually called, but it's at Home Depot near the hardware section. It looks like stainless steel sheet. I used it as turbo heat shield and it worked great. It doesn't absorb the heat much. I had a hard time to cut it as a gasket without wrinkling it so I couldn't make it as gasket.

I have seen those in Home Depot. Galvanized sheet are located in the roofing department. They are cheap but i was afraid they might not give or contour to the flanges.

 

[Brad Bedell]

If you have two flanges, I would clamp them together to form a copper sheet sandwich, drill holes, bolt them together and then work around your copper as to not distort/wrinkle the soft material.

Also, a belt sander or grinder disc works well at making sure your flange is perfectly flat after you weld on it. If you're really into over-engineering this, I would also look for a steel o-ring to burry into the copper. (similar to cylinder head o-rings)

-B

 

[Toysrme]

I'm always late to the party...
I don't like the idea of galvanized sheet at lowes/home depot. Having both cut a lot of it myself. (New home construction) & used it to make a few things on my car. I don't see how someone would cut it to make a gasket. You could trace cut it with a knife, but OMG the work involved on galvanized steel to do that!?
Cutting your own copper gaskets is easier (I do it on several R/C plane engines I run), and has been done for cylinder head gaskets on motorcycles for a *long* time.
When you O-ring a cylinder head, you cut out where the O-ring sits on the head to give the ring a place to embed. That is a lot of work to be building exhaust gaskets!!!



As long as it's not an actual crimp in a gasket (I.E. a little bending is NOT a problem, but an actual bend is). Don't worry about it not being perfectly flat. You're fine. At worst, supply a can of copper-kote for someone to seal it with. That's boarder line over-doing it in all honesty.
(A life-long mechanic friend keeps swearing to use this GM head gasket sealing spray/goop/whatever. If I could remember the name of it, I'd tell you to have people buy that)

 

[stevechumo]

I agree that galvanized sheet is hard to get cut. That's why I failed in cutting it into gaskets. But if you got the right tool to do it, then I'm positive it'll be really great for sealing under high temperature and soft just enough to be pressed in between 2 steel flanges. I used it as a turbo heat shield and placed it right above the turbo (double layer) and guess what, it didn't get too hot and didn't change shape or anything. If you can make it for gasket, I don't think it's necessary to have the ring at the edge like the turbo stainless steel gasket.

 

[jibby]

In plumbing you cannot attach copper to galvanized directly. We use diaelectric unions to connect the two materials. Copper has adverse effect when connected to different metal surfaces... Lime buildup, and other problems can occure.. Just something to think about....

 

[Brad Bedell]

In this case, the galvanized paint wouldn't last. It'd burn off the metal in a matter of hours. I think the debate was between the cheap (and available) galvanized steel vs the use of copper.

Lextreme: is your problem a common one? I have debated having turbo gaskets made from copper or stainless. Knocking out a program for this flange would only take a few minutes and would be a nice product on the laser cutter. The problem is that I generally need to make 75-100 of them to get the cost 'reasonable'.

I had a problem with copper gaskets melting years ago from a turbo application on a 3sgte. (turbo to downpipe) I built the gasket with the above mentioned technique.

 

[Lextreme II]

There are companies making copper head gaskets already. This is not a common one. This is only once case. OEM use a paper like material for sealing. However, I modified the flanges therefore need some custom gaskets.

 

[stevechumo]

In this case, the galvanized paint wouldn't last. It'd burn off the metal in a matter of hours. I think the debate was between the cheap (and available) galvanized steel vs the use of copper.

Lextreme: is your problem a common one? I have debated having turbo gaskets made from copper or stainless. Knocking out a program for this flange would only take a few minutes and would be a nice product on the laser cutter. The problem is that I generally need to make 75-100 of them to get the cost 'reasonable'.

I had a problem with copper gaskets melting years ago from a turbo application on a 3sgte. (turbo to downpipe) I built the gasket with the above mentioned technique.

If you read through my threads above, I mentioned the sheet that looks like galvanize, but I'm not sure if it's called galvanize. Here it is. Remember it worked just perfect for a turbo heat shield. Although its surface looks rough, but in fact, it's really smooth and can be pressed a little.

 

[Brad Bedell]

If you read through my threads above, .

I completely understood what you wrote. Those sheets are in fact galvanized. I was responding to Jibby's comment about the copper/galvanized and used of diaelectric unions. His concerns are really not applicable here as Lextreme wasn't looking to sandwich both galvanized steel and copper together, only either or. In any case, if you use the galvanized steel as a turbo gasket, the galvanized paint/coating would burn off rather quickly. While this sheet would work well for a gasket, I might also add that those fumes can be somewhat toxic.


Lextreme: I generally also try to do a fire ring into the flange. I'll see if I can describe it. Where you have the two flanges come together. One flange(#1) is sized so that your pipe fits into it perfectly. The 2nd flange is welded so that the pipe extends about 1/8" toward flange #1. This fits into the flange #1 about 1/8". I do this with 95% of my custom exhausts/turbo kits and never have a leak. (That doesn't read clear to me, hopefully it is to you) It's similar to the OEM setup you had.

Anyhow, I hate replacing gaskets on a regular basis. The extra 5mins it takes to engineer a connection to never leak is worth it in my opinion.

-B

 

[Pro]

a home jigsaw with an alum blade should cut it no problems.

 

[stevechumo]

a home jigsaw with an alum blade should cut it no problems.

Good idea! I'll try that if I have a chance.

 

[rydning]

Why not make the flanges conical or weld on V-band clam kit from ATP?