proper use of exhaust clamps

[TomFromStLouis]

I just installed the stainless steel exhaust system on my BJ8. It took a while since I am unusually challenged by most things mechanical. Victoria British did not offer mid and rear clamping systems and the PO had an improvised attachment method (including tack welds), so I improvised too. My knuckles look like I went ten rounds without gloves.

Anyhoo, all's well that ends well. So I am really looking forward to that happy ending, if it ever arrives. I had everything ready for the test drive but failed to get out of the driveway. Seems my clamping effort just in front of the first silencers both failed. I tightened them until I noticed the outer pipe closing down on the inner one. Wrong, I guess. So tell me: after jamming the pipes together as much as possible, where do I place these clamps? Center of the join? How much deformation should I get before I stop tightening? Any other thoughts on keeping forward pressure on the joint? Maybe adjust the last attachment just before the tailpipe?

 

[Randy Forbes]

Hard to beat welded joints!

All but the best clamps are pretty miserable, and the best ones (a band-type that can exert a lot of force without deformation) are pretty expensive.

Honestly, get them welded. If you can't weld them yourself, take it down to the local muffler shop.

 

[Keoke]

So tell me: after jamming the pipes together as much as possible, where do I place these clamps? Center of the joint.

Yes that is an acceptable location. However, I would like to suggest that you invest in a tube of Exhaust weld this is a filler sealer that bonds the two pipes together within the joint. Simply follow the instructions with the product. Subsequently, just a good snugging up on the clamp will be required.--Fwiw--Keoke

 

[TomFromStLouis]

I am going to have it welded. Thanks for the feedback.

 

[why]

tom: one thing you must realize is that the board has folks with different experience/knowledge levels as well as different sets of tools. Something tells me you do not have welding equipment. So as will inevitability happen for one of many reason you will have to remove muffler sooner rather than later. If you do not have welding stuff, off you go to a shop which carries its own set of problems. No reason a simple autoparts store cupla bucks muffler clamp won't work. I usually put it pretty near the end of the piece with the slit and tighten about as tight as you can get it. Worse that can happen is you break the bolt on the muffler clamp.
Jay, '65 3000

 

[Andy65]

The stainless is a slightly different diameter than the exhaust manifold clamps. There is a stainless steel sleeve Home Depot Plumbing dept, that gets the diameter right. See earlier posts.

 

[Johnny]

Hi Tom, not sure if your local Midas shop can weld stainless steel. I wish I can help but I'm having similar problems stopping exhaust leaks. I did purchase super heavy duty muffler clamps from O'Reilly's auto parts and they seem to work for awhile. The problem I have is the muffler is too large to seal properly and now that they've been squeezed and pinched so much I'm going to have to have them expanded to put back on. I think Keith may have a expander.

 

[fordtrucks4ever]

Stainless steel has been used in the mainstream on cars since 1975, so its a very safe bet that any muffler shop can weld it. Most shops now have mig welders anyway, so its a no brainer.

If you remove the parts in question, any real muffler shop can swedge the pipe large enough for a proper fit where a clamp will actually work.

I have my own lift and pipe bender. I see this problem all the time on prebent kits. Its an easy fix and looks better clamped with the correct parts than a weld that will end up rusting.

 

[GregW]

Stainless steel has been used in the mainstream on cars since 1975, so its a very safe bet that any muffler shop can weld it. Most shops now have mig welders anyway, so its a no brainer.

If you remove the parts in question, any real muffler shop can swedge the pipe large enough for a proper fit where a clamp will actually work.

I have my own lift a weld that will end up rusting.

Rust? Sounds like the wrong filler rod (or wire) is being used.

 

[Randy Forbes]

Rust? Sounds like the wrong filler rod (or wire) is being used.

FWIW, I've had an opportunity to see a few of the ///M Coupe/Rdstr s/s exhausts I've modified several years ago, and the welds are still shiny.

Using mild steel wire (AR70S?) must dilute with enough of the base metal in the weld pool to absorb chromium & nickel to prevent it from oxidizing.

This will be good to know if your Coupe ever needs what I'm *famous* for :wink:

 

[GregW]

The ///M exhausts may use stainless filler material. I've used both stainless wire for my MIG and rod with oxy/acetylene. The MIG gets a tri-mix gas bottle and the torch needs flux, but the process isn't that much harder than welding mild steel.

 

[why]

The problem seems to be not with the pipe or the clamp but that the instructions failed to tell you that if the clamp does not give a tight enough fit, just buy a roll of thin aluminum from local hardware store, cut a 2-3" wide length long enough to wrap at least 1 and a half times around the muffler pipe, that should make the piece with slit in it a tight hand fit and therefore any help from clamp will insure whole bit does not slide apart--if still loose cut a longer piece. Along with "Beware the ides of March" is "once welded never to be undone" at least for the hobbyist. Over 40 years of hobbyist fooling with this stuff I found keeping in mind getting it apart is an important aspect of getting it together. Oh, just remembered dissimilar metals corrosion between aluminum and stainless, in terms of exhaust system as opposed to fender and shroud another Shakespearian truism: "a difference that makes no difference is no difference."
Jay, '653000