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jerryr10's picture
jerryr10
Last seen: 2 weeks 1 day ago
Joined: 4/20/08
Posts: 2
Propane conversion

I thought I was being smart to buy my 1987 Cat36 with CNG.  Not so good an idea now as CNG isn't available any longer so it's time to convert to propane. I'm sure others have done this.  Can you give me some idea as to the size and model of the locker and how you mounted it in the full length aft lazarette? I realize the stove and hose needs to be replaced. 
Jerry Raphael
Shadowfax #716
Everett, WA

LeslieTroyer's picture
LeslieTroyer
Last seen: 2 hours 6 min ago
Joined: 3/13/16
Posts: 381

Hi Jerry.  Conversion to LPG is mixed depending on the age of your stove.   At best your only replacing the orifices for ones with a 30% smaller hole.  Worst case is whole new stove.   Then LPG tank storage, which requires dedicated storage with bottom drains to outside the boat (ABYC has more info on requirements).  I carry 2 6lb aluminum tanks on the stern. Ugly but works on my Mk1.   

I can usually be found at Skuttlebuts most Wednesday from 3-5.  Their happy hour is not as good as it was but still ok.  Ask for Bob’s table.  

Suremarineservice.com is great vendor for this type of service.  
 

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Les & Trish Troyer
Mahalo 
Everett, WA
1983 C-36 Hull #0094
C-36 MK 1 Technical Editor. 
bakerha's picture
bakerha
Last seen: 2 days 10 hours ago
Joined: 7/23/10
Posts: 226

Jerry - I did this conversion several years ago and have not regretted it.  We replaced the stove as I could not find orifices for my old CNG unit and it had seen better days any way. I built a box in the center of the aft lazerette with solenoid, sensor and drains all accounted for. Some pics here: https://www.catalina36.org/forum/technical-discussion/mk-1-propane-conve...
There are other pictures on that thread of a production housing used by the OP.  You might be able to contact that member for more information too.
His installation seems to take up a lot less space than mine.

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_____________
Harold Baker
S/V Lucky Duck
Sandusky Ohio, Great Lakes
1989 C-36 mkI TR/WK M25XP

Chachere's picture
Chachere
Last seen: 1 day 9 hours ago
Joined: 10/27/10
Posts: 517

Jerry -
Are you sure CNG isn't available anymore in your area?  See www.corpbrothers.com/ma0502/marine/cng-dealers.php#washington
We're still able to get refills (albeit not cheap, around $80 for an exhange) from this company in the north-east US, via some marinas.  
We seem to get about 1 full sailing season (including about a month of cruising) out of a tank, and have a spare just in case.

I've also contemplated putting together one of those devices to refill at service stations that sell CNG
( www.c34.org/wiki/index.php?title=CNG_Refill_Adapter ), but I'm a little skittish about the idea.
Here's a video of someone using one: www.youtube.com/watch?v=OfChHyrV4PE

But long term, I think we want to do this conversion at some point, for sailing out of our region.  Largest impediment seems to be the tank locker location, however, particularly on older boats like ours...  Maybe lowering the lazarette floor on one side of the steering quadrant might work?  In any event looks like it will need to be a custom built locker.

 

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Matthew Chachère
s/v ¡Que Chévere! #466
1985 C36 MKI tall rig fin keel M25
Homeported in eastern Long Island, NY

fid04
Last seen: 1 week 20 hours ago
Joined: 2/25/15
Posts: 1

My MK1 had cng when I got it, with about 2000 psi in the tank. It didn't seem to last very long in comparison to the small propane tank on our previous C30, and my wife wanted a larger 3 burner stove with a larger oven. After reasearching, I learned it was possible to change the burner orifices to use propane, but the ofifice on the oven control is a fixed size and cannot be modified for propane. I collected all the stuff to make the cng adapter described in that other post. Kind of a pain since everything can't be sourced from the same place, and it does require a good machinist to modify the thread on one end of the T fitting from a pipe thread to a straight thread with a recess for a sealing o ring. Used it once. Kind of freaky with the amount of pressure involved and the fact that I was completly alone in the place.Just hook it up, put in the credit card and pull the lever. With all the picky regulations about filling a propane bottle to about 200 psi, there were no restrictions in place for a 2800 psi fill. It filled in what seemed about 3 seconds and only cost a few dollars. Apologies for going off topic some. I ended up getting a 3 burner propane stove, fabricating a back rail mount for a larger composite propane tank with external regulator and solenoid, and all nice new propane hose. The hose goes thgough a sealing bulkhead fitting on the stern in one continous run to the stove fitting.IMHO a propane locker is just an expensive PIA, limiting tank size and taking up valuable locker space.

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John Fiedler
ScottishDuncan
Last seen: 5 hours 6 min ago
Joined: 8/5/14
Posts: 56

After replacing my cng stove with a force 10 2 burner which fits perfectly, I mounted the slim line 6lb propane canister inside a fender (top of fender cut off) which is held on the port side of the pushpit with a single fender holder bolted to the pushpit. Works great! Leaves my lazarette free for various other stuff. I was pushed for time when I had to do this and did not have enough time to design and fabricate an enclosure inside the rear lazarette. I will post a photo when I get back to the boat in a weeks time.

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Duncan McNeill
1984 Catalina 36 #178
standard rig fin keel M25
Channel Islands
Chachere's picture
Chachere
Last seen: 1 day 9 hours ago
Joined: 10/27/10
Posts: 517

Yes, photo please!

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Matthew Chachère
s/v ¡Que Chévere! #466
1985 C36 MKI tall rig fin keel M25
Homeported in eastern Long Island, NY

LeslieTroyer's picture
LeslieTroyer
Last seen: 2 hours 6 min ago
Joined: 3/13/16
Posts: 381
Sure Marine Services caries a nice rail mount system for holding tanks, regulator and selonoid http://www.suremarineservice.com/Galley/Propane-Railmount-Bracket-Assembly/
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Les & Trish Troyer
Mahalo 
Everett, WA
1983 C-36 Hull #0094
C-36 MK 1 Technical Editor. 
ScottishDuncan
Last seen: 5 hours 6 min ago
Joined: 8/5/14
Posts: 56

I saw that rail mount but the $45 cost of the stainless fender holder seemed convincing to me. I had a new fender which i found floating about after a storm which is a perfect fit. Also the fender completely protects the gas cylinder from sunlight which causes the raw aluminium to look shabby after a while. I mounted a breaker to the left of the cooker in the cabin and I enshrouded the gas cable with spiral conduit for sun protection. I am in Scotland right now returning next Friday so will post a photo or two next Saturday.

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Duncan McNeill
1984 Catalina 36 #178
standard rig fin keel M25
Channel Islands
LeslieTroyer's picture
LeslieTroyer
Last seen: 2 hours 6 min ago
Joined: 3/13/16
Posts: 381
My boat came with the cylinders in a stainless fender holder bolted to the stern. One of my next projects is to make a Al holder and skin it in starboard. I reciently installed a propane detector under the galley floor. I have yet to connect to the selonoid ground. Les
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Les & Trish Troyer
Mahalo 
Everett, WA
1983 C-36 Hull #0094
C-36 MK 1 Technical Editor. 
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