Bilge blower hose replacement

Dec 21, 2020
82
Catalina 310 Lake Hefner
My bilge hoses are shot. Catalina installed the bilge blower at the far back of the boat. I got it loose and moved it to the forward bulkhead right under the port aft hatch. Have all the duct run to the blower but how in the world am I going to get it attached to the transom vent? Seems I could if I could remove the vent. I've got a 2004 with the plastic vents. Any thoughts?
 
Sep 25, 2008
6,353
Alden 50 Sarasota, Florida
I’m certainly no expert but I never considered myself ignorant so I have to ask - what is a “bilge blower” and what purpose does it serve? Corollary - is it an explosion proof pump to eliminate hydrogen off gas from overcharged and misplaced batteries?
 
Dec 21, 2020
82
Catalina 310 Lake Hefner
A bilge blower evacuates built up fumes from the engine compartment. The 310 has a 3” intake on starboard aft to feed fresh air. The exhaust is on the aft port and has a 3” blower inline with the hose. They were cheap plastic and just disintegrated. I can’t real the aft vent in the transom to connect the exhaust hose or replace the intake hose. Not real concerned about the intake but want the exhaust to be leak free.
 
Sep 25, 2008
6,353
Alden 50 Sarasota, Florida
A bilge blower evacuates built up fumes from the engine compartment. The 310 has a 3” intake on starboard aft to feed fresh air. The exhaust is on the aft port and has a 3” blower inline with the hose. They were cheap plastic and just disintegrated. I can’t real the aft vent in the transom to connect the exhaust hose or replace the intake hose. Not real concerned about the intake but want the exhaust to be leak free.
Hope this doesn’t sound too pedantic but I inferred you were talking about a bilge blower rather than ventilation of the engine room.
 
Dec 21, 2020
82
Catalina 310 Lake Hefner
No worries. I’m just trying to find someone who’s taken the back vent off so I can attach the hose to a place I can’t reach.
 

Tom J

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Sep 30, 2008
2,094
Catalina 310 Quincy, MA
No worries. I’m just trying to find someone who’s taken the back vent off so I can attach the hose to a place I can’t reach.
I replaced one of the vents years ago. I don't remember it as being too difficult, though. If you don't see any screws visible, there might be a cover that snaps off.
 

Tom J

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Sep 30, 2008
2,094
Catalina 310 Quincy, MA
I’m certainly no expert but I never considered myself ignorant so I have to ask - what is a “bilge blower” and what purpose does it serve? Corollary - is it an explosion proof pump to eliminate hydrogen off gas from overcharged and misplaced batteries?
It is an explosion proof blower that vents the bilge area. Most likely it is required because we have a propane system on our boats, and a propane leak would result in gas accumulation in the lowest part of the boat.
 
Aug 29, 2016
117
Catalina 2004 310 (Hull #250) BC
Hi - I did this exact job - I have a 2004 310 also, and did this job last year. Replaced the Detmar blower with same, as well as the cheap venting hose to the transom. I did not have to take the transom cover off - it attaches quite easily by just carefully threading onto the outlet. Luckily I'm just small enough to fit into the space and with a lot of boat yoga and swearing, got it done. Good luck.
 
Jan 4, 2006
3,983
Hunter 310 West Vancouver, B.C.
Hope this doesn’t sound too pedantic but I inferred you were talking about a bilge blower rather than ventilation of the engine room.
On the subject of pedanticry :facepalm: (is that even a word ?), although the fan does supply ventilation air to the engine room, I believe its for cooling and not removing diesel fuel fumes which are harmless. I believe the fan runs continuously when the engine starts making things a bit more comfortable for the alternator.
 
Dec 21, 2020
82
Catalina 310 Lake Hefner
Hi - I did this exact job - I have a 2004 310 also, and did this job last year. Replaced the Detmar blower with same, as well as the cheap venting hose to the transom. I did not have to take the transom cover off - it attaches quite easily by just carefully threading onto the outlet. Luckily I'm just small enough to fit into the space and with a lot of boat yoga and swearing, got it done. Good luck.
Well, I’m 6’ 2” and 225. I can’t reach it so I’ll hope the cover pops off. Thanks for the reply
 
Dec 21, 2020
82
Catalina 310 Lake Hefner
On the subject of pedanticry :facepalm: (is that even a word ?), although the fan does supply ventilation air to the engine room, I believe its for cooling and not removing diesel fuel fumes which are harmless. I believe the fan runs continuously when the engine starts making things a bit more comfortable for the alternator.
Blower blows out not in. Not really needed for Diesel engines but a good idea none the less. As for propane fumes in the bilge, that should never happen. That’s what the test gauge and solenoid on the tank are designed to avert. Good practice to run a leak test more than once in a blue moon.
 
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Tom J

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Sep 30, 2008
2,094
Catalina 310 Quincy, MA
I believe the fan runs continuously when the engine starts making things a bit more comfortable for the alternator.
The fan only runs when you turn the switch on at the pedestal. It is very loud, and I couldn't stand to have it running all the time. I usually run it for a little bit before engine start up.
 
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Jan 4, 2006
3,983
Hunter 310 West Vancouver, B.C.
The fan only runs when you turn the switch on at the pedestal.
Sounds a little cheap in that they didn't bother with any relays or voltage regulators to keep the fan from overspeeding when your batteries reach full charge.

I usually run it for a little bit before engine start up.
The fan really doesn't serve any purpose then.

It is very loud, and I couldn't stand to have it running all the time.
I know what you mean. I designed and built mine from scratch for the sole purpose of keeping my alternator cool. I had recently treated it to a smart alternator regulator (Balmar ARS-5) and it was cooking itself to death in the 160 deg. F environment. Had real problems with noise and had to change blowers and install fabric air hoses. See the attached material if you want to quiet yours down.
 

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Tom J

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Sep 30, 2008
2,094
Catalina 310 Quincy, MA
The fan really doesn't serve any purpose then.
As stated by the OP, this is a bilge blower. It's purpose is to remove explosive vapors from the bilge prior to engine start. All gasoline fueled inboards are required to have one, and we have all seen the pictures of boats blowing up at the dock when someone forgets to turn on the blower. Granted, the vapors from diesel aren't considered explosive, and maybe most diesel inboards don't have one, which leads me to think Catalina is exercising an abundance of caution, or the fact that propane vapors are explosive is their reason for including the bilge blower.
I have had the habit of turning on the bilge blower in gas powered boats that I have operated, and that habit has carried over to the operation of my C310.
 
Dec 21, 2020
82
Catalina 310 Lake Hefner
As stated by the OP, this is a bilge blower. It's purpose is to remove explosive vapors from the bilge prior to engine start. All gasoline fueled inboards are required to have one, and we have all seen the pictures of boats blowing up at the dock when someone forgets to turn on the blower. Granted, the vapors from diesel aren't considered explosive, and maybe most diesel inboards don't have one, which leads me to think Catalina is exercising an abundance of caution, or the fact that propane vapors are explosive is their reason for including the bilge blower.
I have had the habit of turning on the bilge blower in gas powered boats that I have operated, and that habit has carried over to the operation of my C310.
Thank you for clarifying what I am asking about. I am going to the boat today to see if I can get the cover for the aft vent off so I can get at the hose attachment from the outside as I can’t get at it from the inside. My six year old granddaughter will be here in a couple of weeks. If I can’t get it from the outside, I’ll send her in there.
 
Sep 25, 2008
6,353
Alden 50 Sarasota, Florida
As stated by the OP, this is a bilge blower. All gasoline fueled inboards are required to have one, and we have all seen the pictures of boats blowing up at the dock when someone forgets to turn on the blower. .
do any Catalina 310s have gasoline engines? If not, I’m unclear what purpose a bilge blower has In that model boat.
 
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Jan 4, 2006
3,983
Hunter 310 West Vancouver, B.C.
My six year old granddaughter will be here in a couple of weeks. If I can’t get it from the outside, I’ll send her in there.
I've found that using little kids in boats is absolutely vital in many cases. Why child labour was ever outlawed, I'll never know:cuss:.

Years ago, I had managed to drop a screw in the rear compartment of the boat and it managed to roll under the plastic fuel tank. Now that shouldn't cause any problems :eek: ! ! ! ! After many sleepless nights trying to figure out how to get the screw out of that little hole, I figured on hiring a sailing buddy's son to go in after it. While his father and I were finalizing the safety procedure and safety lines, we find the kid had wormed his way down into the compartment, located and removed the screw, got out, and had his hand out for the $10.00 I told him I'd pay him to find the screw.

That was about fifteen years ago. If that happened today, you'd see my face on the front of the Daily News with the cops hauling me off for child endangerment. Fifteen years ago, the kid earned more money than he's ever seen before in one place, was over the moon having earned the money, and was just starting to see potentially dangerous situations which would serve him well later in life rather than walking in front of a bus while looking at his iPhone.
 
Dec 21, 2020
82
Catalina 310 Lake Hefner
do any Catalina 310s have gasoline engines? If not, I’m unclear what purpose a bilge blower has In that model boat.
I checked the USCG regulations and you are correct: Diesel engine boats are not required to have an engine compartment ventilation system. I also checked the USCG propane system regulations: No required ventilation system inside the boat. Propane lockers must be sealed and vented to the outside. So you are correct: the blower is not required on a Catalina 310. However, I think it’s a good idea and I run it while I’m doing a pre start check on the engine. I shut it off after the engine is started. Still, my OP is how to remove the after cowling covering the vent. It’s glued on so it appears if I’m careful with a slim bladed knife, it can remove it without breaking it. See attached photos.
 

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Nov 16, 2012
1,002
Catalina 310, 2000, #31 31 Santa Cruz
I always thought the blower was to remove heat from the engine area? That said, I seldom use mine.

Totally different vents on our 2000 C310. They are metal.
 
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Dec 21, 2020
82
Catalina 310 Lake Hefner
do any Catalina 310s have gasoline engines? If not, I’m unclear what purpose a bilge blower has In that model boat.
I checked the USCG regulations and you are correct: Diesel engine boats are not required to have an engine compartment ventilation system. I also checked the USCG propane system regulations: No required ventilation system inside the boat. Propane lockers must be sealed and vented to the outside. So you are correct: the blower is not required on a Catalina 310. However, I think it’s a good idea and I run it while I’m doing a pre start check on the engine. I shut it off after the engine is started. Still, my OP is how to remove the after cowling covering the vent. It’s glued on so it appears if I’m careful with a slim bladed knife, it can remove it without breaking it. See attached photos.
I've found that using little kids in boats is absolutely vital in many cases. Why child labour was ever outlawed, I'll never know:cuss:.

Years ago, I had managed to drop a screw in the rear compartment of the boat and it managed to roll under the plastic fuel tank. Now that shouldn't cause any problems :eek: ! ! ! ! After many sleepless nights trying to figure out how to get the screw out of that little hole, I figured on hiring a sailing buddy's son to go in after it. While his father and I were finalizing the safety procedure and safety lines, we find the kid had wormed his way down into the compartment, located and removed the screw, got out, and had his hand out for the $10.00 I told him I'd pay him to find the screw.

That was about fifteen years ago. If that happened today, you'd see my face on the front of the Daily News with the cops hauling me off for child endangerment. Fifteen years ago, the kid earned more money than he's ever seen before in one place, was over the moon having earned the money, and was just starting to see potentially dangerous situations which would serve him well later in life rather than walking in front of a bus while looking at his iPhone.
Great story. As an alternative, Ji might be able to use rigid PVC with some glue on the end to engage the flange. Some peanut butter consistency liquid nails would probably hold it. I can prop up the other end until it sets up.
 
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