Air Horns

I will be installing a air horn setup on our 1987 Krogen Manatee as a Winter project. I plan on locating the horn under the pilothouse roof over hang and routing the air hose to the inside. Looking for some "been there done that " wisdom such as will the length of the air hose effect the operation of the horn ? The Manatee center console area is where I would like to locate the compresser as it is weather proof and houses the split system a/c heat pump unit so it is climate controlled. The trumpet on the horn is powder coated brass and I would like to install a screen so creepy crawlers don't nest in it, any ideas welcomed. thanks
Bill

I would expect the installation instructions to specify the maximum length and minimum diameter of the air hose.

As for the screen, see if the manufacturer offers it as an option.

I installed a pair of Buell air horns a few years ago on our Selene 47. I mounted the horns on top of the pilothouse (the overhang is not big enough to fit the horns under as you suggest). The compressor and reservoir tank (2 gallons) is installed in the lazarette with approx. 35ft of hose run between the tank and the horns. I chose the lazarette location for 2 reasons: adequate space to install the tank and compressor, and compressor noise is located away from pilothouse. One consideration is installing adequate tank size if you choose to install an automatic fog sounder as we did (long blast every 2 minutes). Never had any issue with the long hose run. I believe the hose is 3/8 ID but it is just inexpensive air hose as used for pneumatic tools (Home Depot, Harbor Freight).

Thanks Chris, I'm doing a modest installation compared to your Buell set up. I spotted an AFI Marinco system that seemed to fit the budget on EBay. Trumpet is metal not plastic brass powder coated white and small compresser/tank. Thought for the money I'd give it a try. The trumpet is about 9" long so using the roof overhang will work. Plan to angle the trumpet down so water dosen't collect inside and may install a better quality hose than the mfg supplies with the horn. I tried all s/s 12vdc horns , seem to not last very long and marine surveyors seem to dread them as they never work when tested for survey's. Top notch surveyor told me best backup is the horn's that screw on top of a small air bottle, they always work.

For a clean sound you'll want to mount the solenoid as close to the trumpet as possible. This gives a sharp cut-in/cut-out of the pressure, and so the sound.
This is how Kahelberg reccomends installation.
Mounting the solenoid near the compressor, depending on the distance and hose dia, will give a sluggish cut-in/out, wimpy sound.
I'm running 250 psi air tanks, thru a 125 psi regulator in the engine room, with 1" hi press hose up to the coach roof to triple trumpets.

I like a resevoir as close to the horn as possible. My trawler has a pair of Kahlenbergs that were originally plumbed with 1/4 id inch plastic from the engine room compressor ( a little 12 volt belt driven unit) that was adequate for most situations. On what I call a long blast it would kinda "peter out" at the end. The compressor worked its little piston off just trying to keep up with regular fog signals at anchor. I installed a 4 inch by 18 inch pvc tank close to the horn and replaced the tiny compressor with a pair of 12 volt dc continuous duty permanent magnet compressors designed for offroad jeepers. They are mounted to a dual tank unit with a real pressure switch, all on the forward bulkhead in the engine room. I have a control unit (forgot the maker) that does all of the required horn signals electronically. Fog on the BigMiss is a serious matter, its good to be heard. The bigger you sound the better, to a point.

The Coot's compressor and air tank are in the engine compartment, under the pilothouse floor. The solenoid is under the helm and the horns are on the pilothouse roof. Thus, the air lines have a short run. The set-up has lots of capacity. The only time I've run out of air was when I forgot to flip on the compressor circuit.

markpierce said:

The Coot's compressor and air tank are in the engine compartment, under the pilothouse floor. The solenoid is under the helm and the horns are on the pilothouse roof. Thus, the air lines have a short run. The set-up has lots of capacity. The only time I've run out of air was when I forgot to flip on the compressor circuit.

Click to expand...

What kind of fan is that in the top right of the second picture? We've been looking for some like that, for our ER.

I have a home depot style pancake compressor in the engine room. Horn is from a highway road tractor. Hose is 1/4" OD polyflow all the way from ER to helm and to horn. I use the road tractor valve with a pull string. Works great even if air tank is at 30psi (normally 100). Plenty loud. So no need to run larger dia hose. The pull string is nice as you can modulate it: A gentle pull gets a gentle tone. Pull hard and it blows loud.

I would like a two tone horn, though.

Pancake compressor comes in handy for other things like dive mask (it is oil-less), inflating the dink, running (little) air tools, etc.

Horn and compressor cost way less than alot of marine specific horn systems.

N4712 said:

What kind of fan is that in the top right of the second picture? We've been looking for some like that, for our ER.

Click to expand...

I don't know. I'll try to remember to check the next time on the boat.

Ski in NC said:

...

I would like a two tone horn, though. ...

Horn and compressor cost way less than alot of marine specific horn systems.

Click to expand...

Love the sound of my two-tone horn.

Yes, Kahlenberg components are quite expensive.
http://www.kahlenberg.com/products/marine-signaling/yacht-horns/model-d-2-chimetone-air-horn

Just to be clear, our Buell install does have the solenoid near to the horns, even though the compressor and reservoir are located in the lazarette. The horns run at about 110psi. Despite comments from others, we have had no problem with sound level, duration or fading in/out. I think fading is more likely related to inadequate tank sizing. Ours is a very manly horn!!! Highly recommend fitting an automatic sounder if boating in a fog area.

I would love to have one of those Kahlenberg horns on my boat, but I can't justify the cost. I have an Ongaro dual trumpet electric horn that sounds good but I have to work on it at least once a year to keep it working. My backup is a canned air horn and it always works. The best thing about the canned air horn is you can point it at whoever needs to be warned about some danger and that person can easily see that it's you blowing the horn.

The type of horn set the OP is talking about has no reservoir or solenoid. It uses a small compressor, about the size of a soup can, that turns on each time you press the button.

markpierce said:

I don't know. I'll try to remember to check the next time on the boat.

Click to expand...

That would be great, thanks!

N4712 said:

That would be great, thanks!

Click to expand...

It looks similar to a lot of the same fans used on the larger Sea Rays a few years back. They were nothing more than 12V automotive fans from smaller cars that use electric fans rather than one bolted to the water pump or aux fans for tranny coolers.

Usually $75 on up and can find them through Advance Auto, Autozone, NAPA....

Though Mark's could be a marine item...I know he has a 24V system too...but then again it still could just be an automotive fan from a bus/truck.

Mark...if you like, throw up a pic of your electrical panel ....and we know you have a good one of those....it may be on there to see what voltage it is (to start)....

psneeld said:

It looks similar to a lot of the same fans used on the larger Sea Rays a few years back. They were nothing more than 12V automotive fans from smaller cars that use electric fans rather than one bolted to the water pump or aux fans for tranny coolers. Usually $75 on up and can find them through Advance Auto, Autozone, NAPA.... Though Mark's could be a marine item...I know he has a 24V system too...but then again it still could just be an automotive fan from a bus/truck.

Click to expand...

Oh ok, thanks for the info.

N4712 said:

Oh ok, thanks for the info.

Click to expand...

Here's the original pic that I got the idea from.

psneeld said:

Mark...if you like, throw up a pic of your electrical panel ....and we know you have a good one of those....it may be on there to see what voltage it is (to start)....

Click to expand...

The E.R. blower runs on 24 volts.

Is it the engine room 24V blower? Where does the fan exhaust?

psneeld said:

Is it the engine room 24V blower? Where does the fan exhaust?

Click to expand...

Yes.

There are louvered engine-room vents, gunwale high, on either side of the pilot house. One is for air intake, the other for exhaust.

I'd recommend spraying a little WD-40 into the mouth of the trumpet annually....keeps the note sounding as new and displaces some of the salt build-up.

I wouldn't put an auto or home depot fan into the engine room unless sure it is ignition-protected, as quality marine fans should be. (Vetus make the highest-volume fans for 12 & 24v systems I've been able to find, short of going to the people who +ve-pressure their engine rooms. Model is VENT178; capacity 424CFM; 5.6A draw at 12v (2.8A @ 24v))

HopCar said:

The type of horn set the OP is talking about has no reservoir or solenoid. It uses a small compressor, about the size of a soup can, that turns on each time you press the button.

Click to expand...

Like the ones in the auto parts stores? If that's the case, the compressor should be as near to the horn as practical, not more than a few feet.

Aquabelle said:

I'd recommend spraying a little WD-40 into the mouth of the trumpet annually....keeps the note sounding as new and displaces some of the salt build-up.

I wouldn't put an auto or home depot fan into the engine room unless sure it is ignition-protected, as quality marine fans should be. (Vetus make the highest-volume fans for 12 & 24v systems I've been able to find, short of going to the people who +ve-pressure their engine rooms. Model is VENT178; capacity 424CFM; 5.6A draw at 12v (2.8A @ 24v))

Click to expand...

No real need to be ignition protected on the fan in a diesel boat

Also some of the "bilge blowers" are not designed to be run 24/7.. they have a short life span.
I had a 12" radiator fan setup on Volunteer and it worked really well to cool down the engine room which was about 1000 cubic feet.
HOLLYWOOD

I had a 12" radiator fan setup on Volunteer and it worked really well to cool down the engine room which was about 1000 cubic feet.

Folks at the higher latitudes have been known to use a small circ pump and a box heater for almost silent cabin warming after shutdown.

Our boat came with non-Kahelberg air horns. They worked well for about 3-4 years. Then they were crappy for another year. Then I ripped them out and put in an electronic horn. That's now worked perfectly for 6-7 years. The twin dual-trumpet cost under $200 and the installation was trivial.

It's a personal thing, I guess, but I never really understood the need to have a horn that knocks everyone's socks off. I think they should be very practical things - and because we live in Maine, we probably use our horns more than other boats (because of fog). I really prefer an effective horn and not one that's trying to make a statement.

ActiveCaptain said:

Our boat came with non-Kahelberg air horns. They worked well for about 3-4 years. Then they were crappy for another year. Then I ripped them out and put in an electronic horn. That's now worked perfectly for 6-7 years. The twin dual-trumpet cost under $200 and the installation was trivial.

It's a personal thing, I guess, but I never really understood the need to have a horn that knocks everyone's socks off. I think they should be very practical things - and because we live in Maine, we probably use our horns more than other boats (because of fog). I really prefer an effective horn and not one that's trying to make a statement.

Click to expand...

Stock boat horns are pretty ineffective.

With people running their boats near WOT (obviously not trawlers or sailboats) with the stereo blaring, or operating from a closed cabin, it takes a lot of noise to get their attention and sometimes you need to get their attention quickly. I would rather someone think my horn is too loud than for them to not hear it at all when they need to hear it.

The air horn with a valve control is nice as you can blow a gentle note, or in case of a knucklehead, a full blast.

ActiveCaptain said:

...
It's a personal thing, I guess, but I never really understood the need to have a horn that knocks everyone's socks off. I think they should be very practical things - and because we live in Maine, we probably use our horns more than other boats (because of fog). I really prefer an effective horn and not one that's trying to make a statement.

Click to expand...

Are your feelings toward horns similar to those of my liveaboard neighbor? A fellow berther told me the liveaboard thought I was "showing off" when making a prolonged signal while approaching the breakwater at the marina's exit/entrance. He said he told her it was a required signal.

My truth is: to be effective, the horn has to make a statement. I'm not about to make a half-second "mini" signal when a four-second prolonged one is called for.

If you want loud and distinct, consider a set of train horns.