Exhaust Flex Coupling to Threaded Pipe

[Trés 30]

I'd like to put a flex coupling below the standpipe exhaust but want to be sure it is 100% leak free (to avoid becoming the S/V Asphyxiation). Most flex exhaust is w/o pipe thread so a complete seal seems to be the challenge.

I'm thinking sections of black iron threaded on one end & smooth on the other to clamp flex pipe over (something like the pic); maybe a sealant also (?)

If anyone has some experience w/ this please let me know.

Thanks much,
Leon

[Dave Neptune]

Leon, the flex will rust out in very little time unless it is stainless. Frankly you'd be better off using "hose" if the "water" is already in the exhaust at the spot you want the flex.

Dave Neptune

[Al Schober]

I've never seen the need for flex at that point. On my Tartan 30, that's where I put a 3 pc union fitting - more for assembly of the new exhaust than anything else.

[67c&ccorv]

In Dave Gerr's "Boat Mechanical Systems Handbook" he recommends flexible metal bellows made of Iconel or Hastelloy and lastly 316L stainless steel to connect from the exhaust manifold to the exhaust system. (P106-107)

This to avoid the inevitable cracking of the joint from engine vibration.

Such bellows joints are available with threaded ends to fit the A4 but be advised the cost is pretty stiff!

[Mo]

...all valid points above and very true...just go with what is tried and true.

[Trés 30]

Finally got the exhaust all together (pics to follow). The solution was not quite as clean as I'd have liked, but if it turns out to be a leaky mess I've got a buddy who offered to tig weld it.

If I had to do it again I might order this for $46 + shipping.

This one is nice too but it's $127 + shipping.

[Trés 30]

not real purdy but it's wrapped (and hidden), so what the hey? I used some unions, so maybe removal will be easier (but hopefully unnecessary). A CO alarm WILL be installed, especially since it's my first exhaust job.

67, thanks for the reference to Dave Gerr's book (and some exotic metals), sounds like a great read!
Minimize vibration & flexion stress on the system, yes! Of course I do have B(oat)OCD

[romantic comedy]

Looks good. I am jealous.

Is that paint high heat?

On my tartan 34, I wanted to do something similar, but just did not pursue it. It looks like you are using the same insulation as I used. I used 3 layers and it is still to hot for the cabinetry.

[ndutton]

Is there a vibration issue you're trying to address?

[67c&ccorv]

Well - I guess if it was a diesel!

[Trés 30]

No vibration issue to speak of, just a compulsive overbuilder.

Romcom, that is high heat paint a la MMI. Didn't use 3 layers of (1/8") wrap, so maybe it won't be enough, but will find out soon!!

[Al Schober]

Wow - ceramic tile countertop in the head! First I've seen that in a Tartan 30.
Helped build a 39' 'fast cruiser' about 12 years ago - owner had a granite countertop next to the stove for hot stuff. He got it from the Lear jet people - the granite was about 3/16" bonded to an aluminum honeycomb!

[ArtJ]

Originally Posted by romantic comedy

Looks good. I am jealous.

Is that paint high heat?

On my tartan 34, I wanted to do something similar, but just did not pursue it. It looks like you are using the same insulation as I used. I used 3 layers and it is still to hot for the cabinetry.

In another post 1 gave a source for solid calcium silicate pipe covering which
would totally solve these worries.

[romantic comedy]

Art, is that what you are using on yours? Do you have the link?

[ArtJ]

I have some of it, as I explained a while back, I only briefly installed it 10 years
ago. I got the information from Tom Stevens who used it for many years
on his Tartan 34 regardless of whether he used a water lift or a standpipe.
the stuff was good. It needed a tape applied over it to keep from shedding
powder. Both the tape and a version of the calcium silicate is in another
post. I located a source which was bigger than 1 1/2 id but I am sure
a little more searching will come up with the 1/ 1/2 inch it. I will find the
earlier post and provide the link again here. All it took was a saw to
easily cut the right angles, some stainless wire and some stainless clamps also
must cover with the tape to prevent shedding powder.
I will repost the links in a few minutes

art

[ArtJ]

http://www.industrialinsulation.com/...insulation.htm

Here is some calcium silicate A little more searching should be able to find
1 1/2 inch id.

Here are some links I found on McMaster car both for the calcium silcicate and the wrap tape. The links get you to the general area, I had trouble copying
the exact pages


http://www.mcmaster.com/#thermal-insulation/=sv7kw1

http://www.mcmaster.com/#thermal-insulation/=sv7lws
http://www.mcmaster.com/#thermal-ins...n/=sv7lwsRigid Calcium Silicate Insulation

The high-strength, durable sheets withstand the high heat conditions of ovens and furnaces.
High Temperature Sheets
Maximum Temperature: 1200° F
Heat Flow Rate (K-Factor): 0.73 @ 800° F
Density: 14.5 lbs./cu. ft.
Color: Gold
Meet ASTM E84 0/0 for flame and smoke.
6" × 36"
12" × 36"
18" × 36"
Thick. Pkg. of 2 Pkg. of 2 Pkg. of 2
1 1/2" 9391K51 $25.29 9391K52 $48.69 ______ __
2" 9391K61 33.53 9391K62 66.38 9391K63 $152.23
Extra High Temperature Sheets
Maximum Temperature: 1700° F
Heat Flow Rate (K-Factor): 0.80 @ 800° F
Density: 40 lbs./cu. ft.
Color: White
Can be machined. Meet ASTM E84 0/0 for flame and smoke.
12" × 12"
24" × 48"
48" × 48"
Thick. Each Each Each
1/2" 9353K31 $13.36 9353K41 $94.34 9353K61 $164.09
3/4" 9353K32 17.04 9353K42 120.70 9353K62 200.73
1" 9353K33 20.00 9353K43 134.55 9353K63 226.04
Extra High Temperature High-Strength Sheets
Maximum Temperature: 1700° F
Heat Flow Rate (K-Factor): 1.05 @ 800° F
Density: 55 lbs./cu. ft.
Color: White
These sheets have exceptional strength when compressed. Can be machined.
12" × 12"
24" × 48"
48" × 48"
Thick. Each Each Each
1/2" 93505K12 $32.20 93505K22 $216.90 93505K32 $365.36
1" 93505K14 43.07 93505K24 292.88 93505K34 516.36
1 1/2" 93505K16 70.28 93505K26 470.22 93505K36 832.64
By using this website, you agree to our Terms and ConditionsHome|Help|Returns|Careers|Settings

Rigid Calcium Silicate Insulation

The high-strength, durable sheets withstand the high heat conditions of ovens and furnaces.
High Temperature Sheets
Maximum Temperature: 1200° F
Heat Flow Rate (K-Factor): 0.73 @ 800° F
Density: 14.5 lbs./cu. ft.
Color: Gold
Meet ASTM E84 0/0 for flame and smoke.
6" × 36"
12" × 36"
18" × 36"
Thick. Pkg. of 2 Pkg. of 2 Pkg. of 2
1 1/2" 9391K51 $25.29 9391K52 $48.69 ______ __
2" 9391K61 33.53 9391K62 66.38 9391K63 $152.23
Extra High Temperature Sheets
Maximum Temperature: 1700° F
Heat Flow Rate (K-Factor): 0.80 @ 800° F
Density: 40 lbs./cu. ft.
Color: White
Can be machined. Meet ASTM E84 0/0 for flame and smoke.
12" × 12"
24" × 48"
48" × 48"
Thick. Each Each Each
1/2" 9353K31 $13.36 9353K41 $94.34 9353K61 $164.09
3/4" 9353K32 17.04 9353K42 120.70 9353K62 200.73
1" 9353K33 20.00 9353K43 134.55 9353K63 226.04
Extra High Temperature High-Strength Sheets
Maximum Temperature: 1700° F
Heat Flow Rate (K-Factor): 1.05 @ 800° F
Density: 55 lbs./cu. ft.
Color: White
These sheets have exceptional strength when compressed. Can be machined.
12" × 12"
24" × 48"
48" × 48"
Thick. Each Each Each
1/2" 93505K12 $32.20 93505K22 $216.90 93505K32 $365.36
1" 93505K14 43.07 93505K24 292.88 93505K34 516.36
1 1/2" 93505K16 70.28 93505K26 470.22 93505K36 832.

[romantic comedy]

Thanks Art. I dont remember that thread. I must be older then I think I am.

[ArtJ]

It was part of the fire extinquisher thread. Just search for Calcium Silicate
. l

The only reason I didn't stay with it was because of discovering
the wrap which has been working okay, but the Calcium Silicate would
certainly provide the ultimate insulation and protection.

Just be sure to put the correct sticky wrap on it to prevent powder
flaking off and you will be all set for 20 or more years

[joe_db]

Since this exhaust is in an insulated closed in space, I think even 99% effective insulation would still allow the area to heat up eventually. This seems like it might be a good spot for a blower to be sucking hot air out of.

[romantic comedy]

Joe, air flow would help also.

With insulation, in a steady state situation, the temperature on the cool side will not equal the temperature on the hot side. For most materials the temperature vs distance from the heat is a straight line relationship. Meaning, the further you get from the hot side, the lower the temperature.

[ArtJ]

When I had the calcium silicate hard insulation installed, the surface was
dramatically cooler than the current situation with 3 turns of wrap.
As explained, the only reason i left the calcium silicate was because
I was assured that the wrap was a better solution and the calcium
silicate left a powder - due to my neglecting to wrap it with sticky
high temp fiberglass tape. I have only stayed with the wrap because
it is there and has been somewhat okay ie no burnt wood.

The calcium silicate is by far a much better choice, and was researched
and used by Tom Stevens on his personal Tartan 34.

Art

[Trés 30]

Originally Posted by ArtJ

http://www.industrialinsulation.com/...insulation.htm

Here is some calcium silicate A little more searching should be able to find
1 1/2 inch id.

Here are some links I found on McMaster car both for the calcium silcicate and the wrap tape. The links get you to the general area, I had trouble copying
the exact pages


http://www.mcmaster.com/#thermal-insulation/=sv7kw1

http://www.mcmaster.com/#thermal-insulation/=sv7lws
http://www.mcmaster.com/#thermal-ins...n/=sv7lwsRigid Calcium Silicate Insulation

Wow! love learning about new materials, and that site has everything!

Does anyone have experience with that "rigid very high temp mineral wool pipe insulation"? Seems like it'd be a good product for hot sections.

http://www.mcmaster.com/#thermal-insulation/=t1g8j5

[ArtJ]

Originally Posted by ArtJ View Post
http://www.industrialinsulation.com/...insulation.htm

Here is some calcium silicate A little more searching should be able to find
1 1/2 inch id.


The above link is to a company which makes the proven insulation used by Tom
of Indigo Just call for 1 1/2 version . May have to buy a box size.

Art

[romantic comedy]

I would think about using the flat insulation.