Heat Resistant Bilge Vent Hose ?

[Jd1]

I am finally getting around to installing extra ventilation for my alternator. Looking at the available room, the vent hose will be strapped to the exhaust heat exchanger. I am assuming it runs at engine temperature or about 190F (high temp thermostat).

All the bilge blower hose I have found is wire reinforced PVC and I am concerned that it might not stand up to the temperature it would be exposed to.
Has anyone run across any heat resistant 3" bilge blower hose?
This blower will only be on when the alternator is running hot so it might not have cool air flowing through it when the engine is running. This has me concerned that even if I put some heat resistant material between the exhaust heat exchanger and the vent hose, things might still get a bit toasty for the hose.
Any experience with this kind of a situation? Sources for heat resistant hose ?
I am thinking that aluminum hose might corrode away ....

[model 10]

Aircraft duct hose. Both CAT and SCAT would work but S(silicone)CAT would be the better choice. It's not hard to find, Chief Aircraft , Aircraft Spruce and Specialty, etc

[Jd1]

Thanks Guy, I found it. Not cheap but good to 450 F.

[a64pilot]

Not cheap, but has a smooth interior so very little drag loss in airflow, and is pretty stiff, so it doesn't collapse easily.
I used it for my generator air hose as the supplied hose got hot, collapsed under the blowers vacuum.

[wingless]

My heat extraction system uses this semi rigid aluminum hose for the intake. It is available at Lowes.

It is rated for 435°F maximum temperature.

My custom system is thermostatically controlled, to maintain the setpoint temperature.

[wingless]

Actually my system has this UL-rated flexible hose.

In my application, it is very handy to form the shape that is retained by the hose.

[model 10]

Originally Posted by a64pilot

Not cheap, but has a smooth interior so very little drag loss in airflow, and is pretty stiff, so it doesn't collapse easily.
I used it for my generator air hose as the supplied hose got hot, collapsed under the blowers vacuum.

You are talking about SCEET, not SCAT wich is single wall.

[wingless]

Originally Posted by Guy

You are talking about SCEET, not SCAT wich is single wall.

The SCEET hose is "Not recommended for handling liquids or highly abrasive materials, or for negative pressure applications."

A heat extraction blower will be negative pressure on this hose, against the mfg recommendation.

[model 10]

Originally Posted by wingless

or for negative pressure applications."

I had a plane once that had SCEET for the engine air intake hose. One day the inner liner came loose and killed the engine. I set about looking for a place to crash land, in the mountains of course. There was this brightly colored Buddhist monastery on a hlltop and as I flew by I pulled on the alternate air, carb heat control as something to do and the engine came back to life!

[Jd1]

I don't think a 130 cfm blower has enough umph to do anything to the hose. As is, I am concerned that I will have enough additional air flow. There are two blowers - one to bring cold air in and one to expel hot air but the hose run is pretty substantial.
I think I will try the aluminum hose suggested - it is inexpensive and available locally ....Thanks !!!

[S/V Alchemy]

Originally Posted by Guy

I had a plane once that had SCEET for the engine air intake hose. One day the inner liner came loose and killed the engine. I set about looking for a place to crash land, in the mountains of course. There was this brightly colored Buddhist monastery on a hlltop and as I flew by I pulled on the alternate air, carb heat control as something to do and the engine came back to life!

Well, you owe them a sack of rice!

[wingless]

Originally Posted by Jd1

I don't think a 130 cfm blower has enough umph to do anything to the hose.

That is probably correct.

For my heat exhaust I added two 220 cfm blowers that draw from up high, in-addition to the two identical blowers that suck from the bottom that the manufacturer installed for gasoline fume removal before starting.

My restriction is to NOT run all blowers at the same time, or the hull will implode like an egg shell. It is handy when squeezing through tight spaces to pull in the sides of the hull.