Yesterday I took the boat out for a day on the bay. As the wind decreased I turned on the engine and motored from he SF Bay down the Oakland/Alameda Estuary. I had been motoring awhile and noticed a slight burning smell coming from down below. I determined the burning smell was the exhaust riser heating up the wood box covering it. The box was almost too hot to touch. (note: the engine temp gauge was 160')
When I got back to the slip I removed the box and determined the heat was centralized in the area of the Exhaust Riser and nowhere else. Seeing I had wrapped the exhaust riser with two wraps of titanium heat tape I figured a couple more wraps of fiberglass heat tape couldn't hurt. I picked up two 20' lengths of 2" tape and gave the pipe two more wraps.
I did a test run with the boat in the slip and tested the heat coming from the exhaust riser. It still seemed to get pretty hot but not as hot as it was.
Question... I took a look at Catalina Directs exhaust risers. They seem to have a very thick insulation appearing to be numerous wraps. How many wraps do I need to take care of the problem. Any suggestions out there?
And, has anyone insulated the inside of the box covering the exhaust riser?
There seems to be some good insulation out there?
I plan on returning to the boat next week and put on maybe two more wraps. I figure it can only cut down on the heat... and hopefully solve my problem...
Chris
Chris Stewart
S/V "24~7"
1984 Catalina 36 Tall
Hull #251 M25
(SF Bay) Alameda, CA
Chris,
I am hesitant to open my mouth due to my last fopa im my comments about your system. Chris, you may want to look at some of the last posts in this section titled "Where to find proper sized hump hose". Some of last posts talk about using a wire mesh wrap to create and air gap between the pipe and the foil wrap to reduce temp. You fabricated your system, how close does it come to the wooden cover? It may be closer than the old system, you could consider making a metal heat sheild that screws underneath that cover, standing it off with washers or spacers to create an airgap between the heat shield and the wood.
Cepheus dream
C36 MK I # 825
MK I Tech Editor No Mas
Steve,
I think that's a great idea. I have been looking at some of the profession hi-tech shields. They are a little pricey. Your idea is definitely less tech, less $$$$ and will work just a well. I think another wrap and the heat shield might take care of the problem.
My new exhaust is not any closer than the last system except for the union. It's a big chunk of metal that can radiate a lot of heat.
And... keep up the suggestions. They are always appreciated...
Chris
Chris Stewart
S/V "24~7"
1984 Catalina 36 Tall
Hull #251 M25
(SF Bay) Alameda, CA
Steve - I do not have a 1984 C36 - so mine may be different. But to answer your question about a heat shield on the bottom side of the wood enclosure - mine does have such an aluminum shield. I will photograph that next time I am there and I will post it here.
Haro Bayandorian, 1999 C36 MKII, Sail La Vie #1787, M35B,
Coyote Point, San Mateo, CA.
My '97 has a corrugated aluminum shield on the underside of the engine cover in the aft cabin. Also has a metal 'mesh' wrap on the riser itself, under the heat wrap.
Gary and Cathy Price
1997 C36 Mk II Tall Rig/Wing Keel Imagine...
Hull # 1617
Worton Creek, Md.
Northern Chesapeake Bay