What makes better exhaust gasket material?
06-03-2010, 03:57 PM
#1
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What makes better exhaust gasket material? I'm about to order a sheet of gasket material to make gaskets for V Band clamps. What would be a better material to get, steel core/graphite or carbon composite? The steel core material is .063 in. thick and the carbon composite is .040 in. thick. Not sure which would be better. Thanks.
06-03-2010, 09:07 PM
#2
Not trying to steer around your question, but have you tried banging on the Vband clamp while tightening the clamp down? Someone recommended that for ensuring that your Vbands don't leak. I believe he claimed that he worked around airplanes a lot which commonly use this type of connector. He said that he beats on them pretty hard as he's wrenching down on them. Hope that helps.
06-04-2010, 07:03 AM
#4
Oh, then I wouldn't worry about any gaskets. I've never heard of anyone having any luck doing that anyway. There are people out there who have gotten their v band clamps to seal up leak free. I think the trick is beating the crap out of them with a hammer as you tighten down on them. Just make sure they're clamped down before you weld them into you exhaust.
06-04-2010, 08:45 AM
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I suggested the technique, use it every day at work. Installed about 20 of them last night while re-installing the pressurization system on an aircraft. Tap and turn = leak free and works every time!
Do NOT use a hammer lol (unless you are using a small one or going to be less brutal than the mallet) use a solid mallet, tap it hard, don't bash it to death.
The way V band connections work is by mating two flat surfaces together. I am sorry to say that can affect the adjustment of your exhaust system because you do not have any flexible connections in it to keep it straight.
The reason yours leak, its only because they are not seated right. If you just tighten them, one of ends might seat against the other with an offset and hence leak. Yet you carry on tightening hoping the clamp will bring them back in line. True that, and sometimes that does work. But when hitting the clamp you vibrate them loose and they do seat up perfectly because the clamp will then bring them to a correct inline position.
The V bands you guys use for cars are not to be used with any kinds of seals or gaskets. There are 2 piece V bans with a hinge that do use a steel O-ring seal but those are for high pressure systems. That us only used on valves and the ends will have a groove for the seal to it in.
These are the 2 piece on an aircraft engine, they are used for high pressure bleed air
Do NOT use a hammer lol (unless you are using a small one or going to be less brutal than the mallet) use a solid mallet, tap it hard, don't bash it to death.
The way V band connections work is by mating two flat surfaces together. I am sorry to say that can affect the adjustment of your exhaust system because you do not have any flexible connections in it to keep it straight.
The reason yours leak, its only because they are not seated right. If you just tighten them, one of ends might seat against the other with an offset and hence leak. Yet you carry on tightening hoping the clamp will bring them back in line. True that, and sometimes that does work. But when hitting the clamp you vibrate them loose and they do seat up perfectly because the clamp will then bring them to a correct inline position.
The V bands you guys use for cars are not to be used with any kinds of seals or gaskets. There are 2 piece V bans with a hinge that do use a steel O-ring seal but those are for high pressure systems. That us only used on valves and the ends will have a groove for the seal to it in.
These are the 2 piece on an aircraft engine, they are used for high pressure bleed air
06-04-2010, 10:16 AM
#6
Thanks for the information. If I can go out and get mine to seal up by that method then I might just reuse them for my true dual build.
Do you have to double nut them? When I had mine installed they were leak free but as the heating/cooling process went on they started to leak some. Now it's just obnoxious. I thought that maybe once they were sealed up I could put a second nut on them to keep it from backing out.
Do you have to double nut them? When I had mine installed they were leak free but as the heating/cooling process went on they started to leak some. Now it's just obnoxious. I thought that maybe once they were sealed up I could put a second nut on them to keep it from backing out.
06-04-2010, 11:25 AM
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No, the nuts that come on them are self locking, they should not back out. At least on the ones we use. If they are not, I suggest you get some self locking nuts to replace them or use some nylock nuts. Or you could just put a second nut if you want, shouldn't really matter. Its just the normal way is one nut should do the job.
If you feel that they started to leak after the exhaust got hot, then go ahead and re-tighten them with the engine running so you can confirm while your down there the leak has completely stopped. Although I have never seen a V band leak after a hot cycle (we do an engine run after installing new valves and they get pretty hot, but don't leak unless not fastened right or the seal was forgotten to be installed in the case of 2 piece clamps).
If you feel that they started to leak after the exhaust got hot, then go ahead and re-tighten them with the engine running so you can confirm while your down there the leak has completely stopped. Although I have never seen a V band leak after a hot cycle (we do an engine run after installing new valves and they get pretty hot, but don't leak unless not fastened right or the seal was forgotten to be installed in the case of 2 piece clamps).
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06-04-2010, 12:09 PM
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I had them put on with gaskets before I read this. It can't possibly be harmful or cause them to leak to have gaskets on them can it? I figured it was just an extra safety measure that couldn't hurt.
06-04-2010, 02:13 PM
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Of course it won't harm, you are just using an extra measure to seal the connection.
However, you did defeat the purpose these connections were invented for. It almost makes it seem a flange setup would have saved you all the trouble you went through, and cost you less too?
You learn something new every day bro
However, you did defeat the purpose these connections were invented for. It almost makes it seem a flange setup would have saved you all the trouble you went through, and cost you less too?
You learn something new every day bro
