TheSamba.com :: View topic - Ceramic Coated Exhaust-coat hardware too?

Fri Feb 13, 2009 4:04 pm

Having new HEs and Muffler ceramic coated. Should I have them coat the hardware( muffler to HE bolts etc.) in any way or will it matter?

Thanks!

Fri Feb 13, 2009 4:16 pm

Wonder if stainless steel would work instead. Seems to me that the coating would interfere with the threads. Doesnt sound like it would matter to me.

Fri Feb 13, 2009 5:31 pm

People say not to use stainless cause it won't hold torque with the heat. Or something. Of course I read this after I put a bunch of stainless bolts in my system. I don't have any problems with it yet though. The stainless bolts do still rust a bit what with all the heat.

The proper system is zinc-coated high grade bolts with copper nuts. Ceramic coating the bolt-heads seems pointless to me.

Fri Feb 13, 2009 6:59 pm

The ceramic coating will not discolor or rust. Stainless steel will not rust but it will oxidize. I would recommend stainless steel bolts as they will hole up better than the regular steel bolts. But, do not expect them to remain shiny. You will have less difficulty getting the nuts off after some time.

Since you can't coat bolt threads with the ceramic coating, this will not help with bolt life.

Fri Feb 13, 2009 7:03 pm

i tried stainless and it did loosen up. with non-nylon locknuts, it would work. fine thread with split lockwashers are likely to work as well. i used coarse thread 5/16

Fri Feb 13, 2009 8:40 pm

copper self-locking exhaust nuts are the only way to go. coated bolts too.

VW sells what they call 'Hot Bolt Paste'. Kind of a thick black black paste. Don't have the part number or price right now, but I use it at work. Might be useful with corrosive environments, but rust is not an issue out here.

Sat Feb 14, 2009 9:32 am

obieoberstar wrote: copper self-locking exhaust nuts are the only way to go. coated bolts too.

VW sells what they call 'Hot Bolt Paste'. Kind of a thick black black paste. Don't have the part number or price right now, but I use it at work. Might be useful with corrosive environments, but rust is not an issue out here.
What's the purpose of this paste?

For the OP, no, don't bother ceramic coating the hardware. You'll be wrenching on the bits and will damage the coating. I agree w/the self-locking copper nuts.

Sat Feb 14, 2009 7:09 pm

Stainless will loosen, but only once. What you need to do is go back in a day or two and tighten them again, and they will hold the torque. copper lock nuts aren't a bad idea either, but stainless nuts are fine too. dont forget washers.

iow, stainless is fine, just remember to retorque once, and it should hold after that, just takes a heat cycle or two for the metal to relax to its final state or some such science

Mon Jul 27, 2009 2:25 pm

Forgot to post the finished results

before install

after install

tail pipe

Mon Jul 27, 2009 3:26 pm

stainless is a weird duck. Not all stainless is created equal. Sometimes stainless is perfect for that type application and sometimes if it is a softer stainless it is an accident waiting to happen. I like grade 8 (10.9 I think in Metric) with copper nuts and some anti-freeze. Then use penetrating oil before you remove them next time.

Mon Jul 27, 2009 3:44 pm

I'm curious to see how it will hold up. I got my heater boxes a ceramic coating last year and I installed a ceramic coated thunderbird. Both look like crap now, the heater boxes are covered in surface rust and the thunderbird isn't doing much better.

I expected more from this... Anyway, I did get a 10 year warranty on the coating, so maybe I'll get it redone some day.

Mon Jul 27, 2009 4:02 pm

Wow, the exhaust looks magnificent!

SGK is correct. Grade 8 metric is not the same as Grade 8 SAE!
Go to this page:
http://www.geocities.com/dtmcbride/home_garden/bolts.html
The left-most column is "Metric Class ISO" and right next to it is "Inch Grade SAE". This is where you do your conversion. So a metric bolt with a Grade 10.9 is the same as an SAE Grade 8.

Mon Jul 27, 2009 8:31 pm

SGKent wrote: with copper nuts and some anti-freeze.

Hey Kent- gets pretty cold down there, eh. :lol:

Mon Jul 27, 2009 9:23 pm

now thats a purdy tail pipe. hopefully it lasts, nothing else ever does. and stainless is a beauty, I just removed some from a 3 year old exhaust system, once torque was removed I could back them off w/ my fingers. stainless nuts on stainless bolts, grade unknown just m8s. a VERY wise investment, esp if you follow up on that warrenty

Tue Feb 23, 2010 7:41 am

So, how well is the ceramic holding up? Especially on the heater boxes near the heads where it is the hottest. I'm considering having it done and am curious if it is worth it. Also, if ya don't mind me asking, how much did that set ya back? If I have it done it will be on the HX's and a T-bird header.

Thanks.

Also, I noticed the O.P. hasn't been on in a while so if anyone else has reviews/cost on the coating, post em up.

Tue Feb 23, 2010 11:59 am

Mine seems to be holding up just fine, but ask me in a year how it is. I did not ceramic coat the hardware, for the same reasons listed above.

Here, the exhaust tip is coated, the mounting bracket is not:

Tue Feb 23, 2010 12:50 pm

... when I first had my system coated it looked as if it were chrome, all shiney and reflective. It has been seven years now and it has dulled dramatically, but ceramic coating does not have to be shiney to work its magic.

Tue Feb 23, 2010 9:08 pm

Jeff Geisen wrote: ... when I first had my system coated it looked as if it were chrome, all shiney and reflective. It has been seven years now and it has dulled dramatically, but ceramic coating does not have to be shiney to work its magic.

Thanks for the replies. So seven years later and no rust or anything? I'm not as concerned about the look as I am the protective qualities but the look would be a bonus. 8)

Wed Feb 24, 2010 3:01 am

Check out Jet Hot.

Wed Feb 24, 2010 4:19 am

In both my buses I removed the stock exhaust studs in the heads and tapped the holes (no drilling required) for 3/8" stainless steel studs. I've never had a problem with them loosening up. I did the same on the muffler as well.

The biggest problem with stainless steel I found is sometimes the the threads gall and the nut and stud come out as one.