Exhaust wrap kit
 

We just added an exhaust wrap kit to our product line.

Each kit includes 15 feet of 2" wrap and two end clamps. The wrap is 1/16" thick and is usually sufficient to cover 4 to 5 feet of the 1-1/4" piping commonly used in constructing the hot section of an exhaust system. When the wrap is used so that there is approximately 1/4" of overlap, the temperature radiating from the pipe is reduced by 50 to 60 %. When a pipe comes within close proximity to a cockpit floor or other structure, the wrap can be used in two layers.

Don

so...
 

Hi Don, so is this for use in wrapping the flexible exhaust hose portion?

No, this is for wrapping the hot pipe section. By the time the flexible rubber exhaust hose starts, the water injection has lowered the exhaust temp.

It's used to wrap the HOT EXHAUST section.
See attached pic...

Jerry,

I like the design of this system, can you tell me how you hooked up the exhaust water hose

http://www.moyermarine.com/images/532.jpg

Moyer Product No. - EXHT_01.1_324 - can be found on this page.

I made my own little "injection port" when I cobbled up my hot section. A standard black iron "T" with an adapter bushing and a hose barb.

Exhaust Hot Section Temperature
 

Don's tape is rated for 1400 F so I'm wondering what is the actual temp of the hot section. It would be good to know this as there are lots and lots of posts here from folks wondering what thread sealant should be used. I find lots of recommendations about what has been used but no one answers the question: what is the top-end temperature off the exhaust manifold.

I've shot temperatures at the top of my hot exhaust rise at 500°

500
 

That would be 500 outside the tape right? Given the tape insulation, the temp on the actual pipe would be higher.

The temp of my exhaust flange was 550. The engine was warmed up and running at 1500 rpm, no load.

I used an infra red gun. Nothing covering the flange.

No thread sealant should be used on a pipe hot section. It will rust and carbon itself together nicely, and should be completely replaced when necessary.

Agree completely...pipe thread seals when tightened. There is a possibility of a drip if you do not (or cannot) bring those pipes tight in the orientation you want your hot exhaust to lay. Normally you can work it, with two good pipe wrenches, and seal the whole thing piece by piece in the orientation you want.

Thread Sealing
 

In my case the orientation just doesn't work. On one fitting, fully tightened is about 90 degrees past where the pipe is correctly aligned so more than a drip is involved. There are two other fittings that also leak but not as badly.

I need to consider a second best solution: a thread sealant. Most sealants available at retail are rated to about 400 degrees. I expect what will happen is that the sealant will hold back any leaking while corrosion takes its course and fills in the gaps. If I've got that right, then I should be good to go.

Alternatives are to shop around for piping that I can align or to use something like JB Weld.

Any comments or suggestions are appreciated.

Jb weld will smell for a long time, every time it gets hot.

You can weld the pipe. I considered solder, or silver solder.

Are we still talking about hot sections? If yes, why the drip? There shouldn't be ANY water or liquid of any kind in the hot section so nothing to drip.

Consider buying a pipe tap. Just a small increase in thread depth can change the "locked" orientation in a hurry.

+1 on this.
Be careful of leaking exhaust systems and carbon monoxide poisoning.
If you are desperate I think TFP paste is good to 700 degrees. Available at your local hardware store.

TRUE GRIT

Exhaust Hot Section Temperature
 

I'll wind this up so others can make what they will from this thread.

I ended up going with Permatex Copper. This is not a sealant but a gasket- making paste--comes in a tube. It is rated to 700 degrees (F) intermittent which is about 300 degrees higher than any of the permatex sealant products I found.

It did seal the gaps but as was suggested in several comments it smoked quite a bit. I've run the engine now for about an hour and a half so I could burn off the stuff before going out.

I think my approach is right for anyone who has a severe alignment problem. Others suggested that no sealant was necessary because any gaps would seal themselves in time. Probably true, I just wasn't sure how long that might be so I went with the permatex figuring that a sealant would handle the leak until the rust built up.

Jim...I've used Permatex #1 (dark brown stuff) for my hot section and it has performed well. Glad you found something that worked. You never know when someone may google search later on and following up always helps.

If you have a big enough leak, chances are no sealant can hold it back, because the exhaust pressure is greater than the ability for a sticky substance to stay put.

From Canada Eh!
 

When I rebuilt my hot section this week I used MASTERS® METALLIC COMPOUND by G. F. Thompson Co. Ltd., Newmarket, Ontario, Canada.

It's rated for 550 degrees F and 6000psi, unofficially its been used for steam way past 550.

I also used it as never-seize/lock-tite on my cradle bolts today, the nut won't free spin off and will undo next spring.

Last year the can cost ~$40cdn and should last ~50 years at my rate of use.

Bruce

how high is the riser does the discharge need to be lower than the engine side

My riser goes up 5 inches (I think...might be 4 or 6), does a 180 degree turn, and then goes back down the same distance. You want the riser as high as possible and the other end as low as possible * as long as it is still higher/even with the water lift*. You do NOT want it to have any upward slope between riser and water lift at all.

I remember reading somewhere that the water injection point should be at least 3-4 inches below the lowest part of the high loop. More is better. This is to prevent backward migration of moisture via splashing.