CO2 horn conversion

In Michell's (sanity) thread I have a horn, we discussed the old air horns that used a disposable cartridge of Freon to drive them. Since these larger Freon cylinders are no longer available, (the Freon tank about the size of a propane torch tank) it got me going on investigating long overdue alternates. I haven't had a horn it at least 5 years!!

The air compressor and tank method always bothered me. Besides being expensive (about $400 plus) I never liked the idea of driving along and hearing a air compressor start up and run under the bow deck of the boat ether. They also draw around 18 amps - although the on time to build up the pressure after a couple of horn bows is only about a minute, that 18 is a lot for our older boats with small alternators.

Looking into both a small bottle of nitrogen and CO2 I decided on the CO2 because it's a liquid and when it converts to a gas it's about twice the volume (cu. ft.) as the nitrogen - I don't want to be changing that bottle very often!! The 5lb. cylinder of CO2 I calculated out to be about triple the volume as the old Freon depending on the temperature. Both CO2 and nitrogen however do require pressure regulation. the air horns run on a nominal 100PSI. This regulation requirement was the reason the Freon were used - R12 depending on the temp has a vapor pressure just over the 100psi.

5lb. CO2 tank under bow deck


Regulator, solenoid and mounting to bow lifting ring down rod


Tank base


The 5lb aluminum CO2 tank I found new on ebay for $48.00 If you find used, it will be cheaper but be careful with the expiration date for tank hydro testing. Buying used isn't bad because when you have it filled, typically you will get another tank and not yours anyway.

I went to my welding gas supplier and the 5lbs of CO2 was $15.00

I did some testing on shop compressed air and found the horn to be very happy at 100psi. Below about 80psi, the horn diaphragm (it makes the noise) has a problem even vibrating. The regulator needed is the higher pressure type used on soda gun systems. They will be adjustable for a low pressure max of about 160lbs. Beer CO2 regulators max out (blows the safety valve) at only 55psi and will not work.

I got my regulator from a friend but did shop on ebay and saw them going for as low as 28.00 used and 49.00 new (buy it now price)

Well, now it's off to get a new solenoid valve. I found out my old one leaks! Not surprising being 45 years old! Probably the reason that 30lb tank of reclaim freon leaked out 5 years ago!!

Yeah Pete, that's not going in your Dunphy is it?

Pete,
Did they use freon tanks in factory installations of horns,/ what "generations"?

I've seen a couple of types of power sources... My 68 cuda has an under-dash compressor, which I have no reason to believe wouldn't have been original to that horn. Have you seen these?

The other is the "bicycle-pump" type that is still in it's original box.


btw, you know Im just ribbing you on the tank... I am going to check that out myself...Looks like a great option!
   

8122pbrainard wrote: Steve and Bruce, Knowing I have that tank under there, I may be inclined to blow the horn more often?? I'll see what happens!

Everyone will say there goes Pete, he's blowing his own horn

It works!!! Fantastic!!!

The delay in getting it tested was replacing the original solenoid valve. When I hooked it up I found the 45 year old valve leaking. Probably where the 2 - 30lb tanks of reclaim Freon went to that I had hooked up to it!! I couldn't hear the leak with the hose to the horn hooked up.

I ended up getting a aluminum body valve from Buell (the air horn manufacturer) figuring it would be best suited for flow and shut off ability. I'll still shut off the tank valve when not using the boat.

Now, the true test will to see if my calculations are correct on the usage I'll get out of 15lbs of CO2. I'll make sure I go under plenty of bridges this summer so I have a reason to blow it. I'll keep track of the blows!!

BTW, the pressure regulator is set to 100psi.

bump for bill

8122pbrainard wrote: I thought I'd report that the 5 lb. CO@ still has plenty in it after 11 years. Deduct 7 for the X55 being laid up and that makes it 4 years of usage. So, I'm happy that I didn't go with the air compressor surge tank retrofit. I'll have to crawl under the deck and take a look at the gauge to see how much is actually in it. I had expected some leakage through the years but evidently that solenoid valve held tight and I didn't even shut the tank valve 7 years ago.

So if you haven't looked at the gauge, how do you know there's plenty left in it ?

Maybe you honked the horn twice and now the bottle's only got one more last dying gasp of a honk left in it

You should probably check the hydro date too while you're crawling under there

You should be good for maybe 20 more years of "honkin" according to this guy