Air Horn Question

[lawndoctor]

I bought a Kahlenberg air horn and am installing it before the season starts here. I plan to use a rocker switch for the air compressor, and use the original momentary horn switch on the helm to actuate a solenoid valve that will sound the horn.

In this configuration, the air compressor will come on from time to time to maintain pressure in the air tank, much like the water pump does to keep the fresh water system pressurized. I'm thinking of mounting the compressor and tank inside the helm console, where there is ample space and air circulation under the instruments.

My question is, how loud is the air compressor when it operates, that is, will the compressor be audible to people sitting in the cockpit, over the sound of the engine when I'm under way?

Thanks for your input and advice.

 

[sbw1]

We've got a different brand of air horn and the compressor is installed in our radar arch next to the helm seat. We can not hear the compressor run. Why not power yours up and listen to it?

 

[wingless]

Which horn did you purchase? Did you go plain or chrome?

Please post picks.

On my boat the ignition protected environment includes underneath the helm.

Does that also apply to your boat?

If so, the spark from a compressor cycling is not a good mix.

Can you place this at that location and plug it in w/ an extension cord to experience the noise?

There are rubber vibration isolators that would help w/ noise.

Remember to put the solenoid valve as close to the horn as possible.

It won't hurt to put an accumulator tank near the valve too.

 

[lawndoctor]

I bought the K-380 in chrome, a nice little unit they make for smaller recreational boats. Will post some pics when I get it installed.

Thanks for pointing out that the space under my helm console might be an ignition protected area. I hadn't considered that. It's not near the fuel tank or any fuel lines, and the fuse panel and all the glass fuses that can pop are right there, so I would not think it is an area where everything in it must be ignition protected, but I could be wrong. I didn't see anything about the issue in my owners manual.

Do you think Sea Ray would be the best place to find out?

 

[osd9]

......On my boat the ignition protected environment includes underneath the helm......

Are you sure about that? Otherwise, all the guages, lights, light switches, radar, VHF, etc would have to be ingnition protected....including the ignition switches themselves.

Under the helm is basically the same environment as the cockpit area itself....

 

[lawndoctor]

I didn't see anything about the issue in my owners manual.

Correction: My owners manual has a section entitled "Ignition Protection" which says "All electrical components in the engine compartment must be ignition-protected to avoid the possibility of creating sparks in a gasoline environment."

It doesn't say this for any other area of the boat. I think this means that the space under my helm console is an acceptable area to put the compressor.

 

[wingless]

On my boat the ignition protected environment includes underneath the helm.

Are you sure about that?

Under the helm is basically the same environment as the cockpit area itself....

The volume that includes the engine compartment, starboard side compartment and underneath the helm is open, contiguous and sealed from the rest of the vessel.

It is my assumption that everything within that volume needs to be ignition protected.

 

[osd9]

Using that logic, then your port side areas would also require ignition protected devices....like the cockpit fridge, icemaker, courtesy lighting, the shop vac you plug into the ac outlet and....... the cockpit itself...there is no sealing between the helm area and the cockpit.

 

[wingless]

The Kahlenberg K380 is a great horn. Good choice!

 

[wingless]

On my boat, as stated, that volume is sealed from the rest of the boat. It is also sealed from the cockpit.

 

[osd9]

Your helm area is not sealed from the cockpit. Open the little door under your wheel where the fuses are....you can see right up there. Also, do you think that the gauges on your dash are making an air tight seal...or the dash mounted VHF? Did you seal your custom E120 starboard to the dash?

I have some thoughts....

Gas fumes are heavier than air and don't raise above the highest supply of gasoline itself in the ER. On an express boat, the cabin is below the level of the engines in the ER and it needs to be sealed from the possiblity of gas fumes entering through any voids.

Think of an Aft Cabin boat....the engines are below the living space, right under the couch, seperated only by a few hatches....hathces which are not 'sealed', simply closed. There are definite voids between the two, but the voids are all 'above' the highest source of fuel/fumes.

I'm willing to accept that this logic may be flawed, but more importantly, I really would like the 'real' answer.....

 

[wingless]

Your helm area is not sealed from the cockpit. Open the little door under your wheel where the fuses are....you can see right up there.

That little door is sealed with a gasket.

All other openings to that volume are also sealed.

All hoses and cables exiting that volume are sealed w/ goop by the factory.

 

[osd9]

You're forgetting about what is behind that area....the stuff I talked about above.....the switches....are they sealed and ignition protected? Is the light dimmer ignition proteced? The factory installs the AP control computer back there...is it ignition protected? Take the stainless covers off of your shifters/throttles.....youl look right into the space...no gasketing! The cup holder in that storage area on your stbd wall...no gasket...it actually has drain holes in the bottom!

 

[osd9]

That little door is sealed with a gasket.
.....

I don't remember if the door is gasketed, but the latch isn't...

 

[boatmailster]

That little door is sealed with a gasket.

All other openings to that volume are also sealed.

All hoses and cables exiting that volume are sealed w/ goop by the factory.

area under dash is not sealed out and doesn't require ignition protected equipment.

all wiring and linkage is sealed to prevent carbon monoxide from entering to cockpit from bilge

and what about automotive style fuse block under dash? those fuses create a sparks when shorted.

 

[NorCal Boater]

The compressor and tank on my '89 340da is in a cabinet under the helm seat. It does cycle on and off and it is noisy But I love my air horns and in my mind the compressor noise is worth it. Alslo, my compressor is 20 years old so the older technolgy may be louder than the new stuff.

 

[osd9]

area under dash is not sealed out and doesn't require ignition protected equipment.

I agree

all wiring and linkage is sealed to prevent carbon monoxide from entering to cockpit from bilge

I don't agree. The areas are not sealed. I don't know what boat you have, but I can speak of 4 larger DAs from 1993 through 2006, 33' to 41'. There are numberous voids at many locations between the ER and cockpit area. Every winter season I would place my Boatsafe ER heater in the bilge and snake the cord outside the ER into the cockpit to plug it into the cockpit convenient outlet. I've run wires from the ER, to the helm without having to drill any new holes...(the Smartcraft gauge in my pic above for one). There are others....

and what about automotive style fuse block under dash? those fuses create a sparks when shorted.

good point.

 

[wingless]

There are numberous voids at many locations between the ER and cockpit area. Every winter season I would place my Boatsafe ER heater in the bilge and snake the cord outside the ER into the cockpit to plug it into the cockpit convenient outlet. I've run wires from the ER, to the helm without having to drill any new holes...(the Smartcraft gauge in my pic above for one). There are others....

What openings exist that don't require removal of components, panels or opening hatches w/ gaskets to access the engine room?

There aren't any on my boat.

Which imaginary border is the demarkation point between the engine room and the non-ignition protected environment?

Is it the large opening above the fuel tanks from the engine room to the side compartments?

Is it the large opening from the side compartment to behind the helm?

Those areas are all continguous to the engine room and all are sealed off from the rest of the boat, unless gasketed hatches are opened or sealed panels are removed.

Yes, there is a drip hole under the cup holder and yes the throttles are closed but not sealed. I think that is it for cockpit to bilge openings.

There aren't any cabin to bilge openings.

 

[osd9]

We need to move this discussion, and it's contents, (mods...!!!) to another thread. Some folks with good input may not be reading or responding to this thread because they have no interest in 'air horns'. Besides, this discussion concerns safety and should have it's own space.

We can continue discussing once a new thread, populated with relative post, is created.

I apoligize for going so far off topic....

Air horns are great!!!! I love mine!!!!!

 

[lawndoctor]

my compressor is 20 years old so the older technolgy may be louder than the new stuff.

Thanks. Is yours a Kahlenberg, AFI, or something else?