Exhaust How Do I Seal An Exhaust Slip-Fit Connection?

[DuctTapedGoat]

Solder would melt under pressure with the heat from an exhaust.

It wouldn't take a full on welder, I have an Oxy-Mapp rig, cost me just a few bucks. It's just hoses with valves and a tip, but for the simple stuff I do, it's really enough.

 

[motorpsycho]

Just how i do it. I used to seal holes in gas tanks. I had a metal block/bar i would heat up, then use regular old solder touch the heated block near the hole, and melt it in to close the holes. Did it with radiators too.

Not sure about exhaust as i would just use a welder normally, but you could technically just use a soldering iron and some solder. But I am not sure about if the exhuast owuld get hot enough to remelt the solder.

the way you are describing your method doesn't sound like it would work very well to me.
you want to heat the actual area(hole) that you are trying to solder.
by heating the metal block that you are talking about, and not the area, the solder won't stick to the hole for very long. it may cool down, stick and become solid, but that's a cold solder joint. a cold solder joint will usually fall off after awhile. in order to solder correctly you have to heat the area that needs to be soldered, and the heat will draw the solder into the hole. the heat around the hole will assure that the solder and the metal will cool together and become more solid. (just watch a plumber "sweat" copper pipes.)
brazing is like soldering but with a higher heat. to get good strong solder joints you have to use a propane torch, silver solder and acid flux. resin core solder is not as strong and won't stick to some metals.
brazing rod has an outer shell made of flux, that melts when it gets hot enough and this makes the brazing rod (brass) stick to whatever you're brazing.

 

[motorpsycho]

Solder would melt under pressure with the heat from an exhaust.

It wouldn't take a full on welder, I have an Oxy-Mapp rig, cost me just a few bucks. It's just hoses with valves and a tip, but for the simple stuff I do, it's really enough.

on the other hand, correctly applied silver solder will not melt under the heat of exhaust. I silver soldered these 3 rings to my pipe to cover up a weld, and that was last summer and 150 miles ago. the 3 rings are right at the hottest point on the exhaust. I have no idea if silver solder would hold up on a slip loint tho because you would be trying to seal the pipes. IN this case, these rings are just cosmetic and the 2 peices of pipe are welded together, which is what's doing the actual sealing of the joint.

 

[DuctTapedGoat]

y heating the metal block that you are talking about, and not the area, the solder won't stick to the hole for very long. it may cool down, stick and become solid, but that's a cold solder joint. a cold solder joint will usually fall off after awhile. in order to solder correctly you have to heat the area that needs to be soldered, and the heat will draw the solder into the hole. the heat around the hole will assure that the solder and the metal will cool together and become more solid.

on the other hand, correctly applied silver solder will not melt under the heat of exhaust.

I should have clarified - standard electrical rosin core solder won't hold up - especially if you tried to do it with a standard soldering iron, no matter what you did, the joint would be cold. With the heat and vibration the exhaust receives, a cold joint wouldn't last a hundred miles.

 

[retromike3]

silver works

I used silver to replace the copper pipe I had in my SBP tuned pipe. I was melting the copper so I replaced the tube with a steel pipe of the same diameter. Put it on and have had it going for about 15 hours (according to my new tack) I still have one place that I did not weld(the other joints have brass) on my pipe in case I needed to "tune it" a bit more.

I went to the hardware store and got some heat resistant tubing that is good for four hundred degrees. Its been holing together for the same time. It was a bit of a pain to slip on and I do have two clamps on the tubing, just in case.


mike

 

[rustycase]

I like your setup, Motorpsycho... will look for other pics of your bike...
rc
sry, that's an off-topic!

 

[skrew37]

what diameter of the high temp silicone hose is needed for exhausts in general? and if using copper, what size are those couplings?

 

[DuctTapedGoat]

7/8" - 1" Id

 

[skrew37]

Thanks. Did anyone ever hear of GatorBITE couplings sold at lowes? They're compression fit (just push the copper pieces into them and they "bite" on also creating an airtight seal. I looked up the o-rings that are inside and they're rated to 250 degrees. I found the same type of o rings (red silicone) that are rated to over 450 degrees. I wonder if your could just pop out the stock ones and replace with the higher rated ones. Could these could work for sealing up an exhaust? The look would be very clean, especially with their copper-mirror finish...hmm...

 

[motorpsycho]

Thanks. Did anyone ever hear of GatorBITE couplings sold at lowes? They're compression fit (just push the copper pieces into them and they "bite" on also creating an airtight seal. I looked up the o-rings that are inside and they're rated to 250 degrees. I found the same type of o rings (red silicone) that are rated to over 450 degrees. I wonder if your could just pop out the stock ones and replace with the higher rated ones. Could these could work for sealing up an exhaust? The look would be very clean, especially with their copper-mirror finish...hmm...

I have never seen those (and i got to Lowes quite often).
i would guess that the original o-rings wouldn't hold up because the exhaust can get hotter than 250, especially right where it exits the engine.
if you could replace those with the 450 degree silicone ones, they might work.
this might be an easy wat to make a custom exhaust, but it may end up looking like a plumber made the exhaust for you.
on a certain style bike with a certain look, they might be right at home (think rat rod).