A year ago when I bought the boat Hull 239 I had residual diesel in the bilge. Not a lot diesel but a scrim. I have replace all the fuel lines and components except the return line. I have placed absorbment mats under the engine, transmission, the fuel filter area. These all are dry. The bilge is dry except when it rains and come down the mast. When that happens the scrim show up again. This is not a lot of diesel but show huge win the pumpp get on and empty's out.
Any ideas where to look?
I bought my 1985 Mk1 last year like you. My first major project was to re-do all the wiring. What a messy job, as all the bilge run wiring was coated in thick tar. The 30 yr old fuel tank was corroded and leaking on the bottom. My theory is that years of leaking and evaporating diesel left behind the thick tar. What a mess to clean up.
If/ when you lift out your tank to check it, you can torque the hidden keel bolt under :-)
Paul
Paul & Ann -
"Freestyle" -
1985 C36 #454 -
North Puget Sound, WA
Maybe the old fuel got further up on the bilge up under the sole itself before you bought it & when it rains, the water runs down the sides and creates this problem. Try cleaning up under the sole with a solvent and long handled brush.
You don't mention it but I assume you have no problems starting the engine. I had a similar fuel/bilge problem to find that I had a pin hole from rubbing in the secondary filter (this was on my C30/U25). The pressure would drip fuel out of the pin hole after running and then I'd have to rebleed before it would start. This happened after a week of no use... it would start OK after a day of sailing.
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You also might want to list your boat type in your signature. Do you have a Mk I or Mk II?
Chuck Parker
HelenRita 2072 Mk II
2002 Tall Rig - Winged Keel
Atlantic Highlands, NJ
Thanks guys for the reply. I have a C36 Mkl. I replaced the fuel components and plumbing. I cut a hole in the top of the tank evacuated the fuel filtering it into jury jugs using coffee filters, then cleaned the tank.
I have no problem starting the engine.
I had to replace the cabin sole so I cleaned all the drain slots and under the sole. I took the framework under the sink out so I had good access under the sink. Could not find any diesel trails from under the tank. I topped the tank off and after 4 months no change in fuel level. If it is leaking it has to be avery very slow drip.
I'm not saying this is where your fuel is coming from. It was just my experience. Once I got my fuel out of the tank, I could see down inside and it was nice & shiny. I was so happy. Until I pulled the tank out and scraped the bilge goop off. Here's what it looked like. The holes were minuscule, really only showing the fuel leaks when left to sit on a paper towel.
The new tank from Catalina Direct, is rectangular, rather than tapered like the OEM to follow the hull down to the lowest point, (thus sitting in bilge water). I had the new tank Rhino coated, and it sets on a piece of pressure treated 4X4 cedar at the bilge lowest point, so the top of the tank is level and the bottom is out of the bilge water.
Paul & Ann -
"Freestyle" -
1985 C36 #454 -
North Puget Sound, WA
pelbel
Thanks for the reply. I fear this is the problem. I really dread pulling the tan. Tomorrow I am going to the boat and work some paper under the tank to either verify this is where the leak is at or put that issue to rest.
Removed the paper today and it had diesel on it. it was not wet but diesel was present. So the tank is leaking. My fix will be to remove the tank clean it the hit with a palm sander with 80 grit paper. Wipe it down with lacquer thinner then West marine Epoxy with a layer of mat more epoxy and a layer of roving to the bottom and sides.
Sounds like a good plan. When I posted about mine last year, several people seemed to have had good results either with epoxy or fiberglass. I just went with a new tank.
Here it is before install with the new Rhino coating.
Unlike me, you'll have more money left over for other things :-)
Paul
Paul & Ann -
"Freestyle" -
1985 C36 #454 -
North Puget Sound, WA
Ok, guys; I am in the same boat here - just different hull number #584. :-/
Question: Did you have to pull the hot-water heater out as well to replace the diesel tank?
I am faced with this exact problem I fear.
Mitch
1986 Catalina 36 MKI
S/V "Blessing"
Kema, TX
Hull: #584
M25 w/ Oberdorfer Conversion
My water heater had to be replaced anyway. So it came out. Tank does go in& out from the top. I'm sure it was easier for me to work w/out the W/H in the way.
Paul
Paul & Ann -
"Freestyle" -
1985 C36 #454 -
North Puget Sound, WA
You should not have to. As I recall it was only removing all the hoses and the wires, plus unscrewing the feet of the tank. In my boat there was a 2x4 also on the top of the tank by the aisle that was used as a spacer to keep the tank secure. I emptied the tank and it was pretty easy.
Gary Bain
S/V "Gone With The Wind"
Catalina 36', Hull #: 1056, Year: 1990, Engine: M-35
Standard Rig
Moored: Boothbay Harbor, Maine
Home: Auburn, Maine
It has been over a month now since repairs were made and the tank was re-installed. I am happy to report the leak is fixed. No diesel in the bilge.
Now for the process of removal and re-install. I did not have to remove the hot water heater. I removed the screws that fasten the water heater down and moved it all the way and to port as far as it was allowed. I had to disconnect the water lines going to the sink and move them all the way. At that point it was ready for removal. I lifted the port end of the tank up and stood it on its starboard end and lifted it out.
The damage to the tank was similar to what most of you have experienced. I then used my palm sander and 60 grit paper to sand the bottom and score it up so the epoxy had a good surface to bond to then I cleaned it with acetone. I then laid down a coat of epoxy then applied the mat using a fiberglass roller to roll it in to get it well saturated then more epoxy, then the roving and more epoxy. I went 8" up the side and end to make sure all welds and corners were covered.
I have uploaded some pictures for your review. Total cost about $30.00
Nice.
Thanks for the update here.
This is my next project.
I have two cups of diesel in my bilge right now...um...make that three...
Mitch
1986 Catalina 36 MKI
S/V "Blessing"
Kema, TX
Hull: #584
M25 w/ Oberdorfer Conversion
Good information here.
I pulled my aluminum diesel tank on Sunday, thinking there was no way to perform the work without removing it.
Instead of fixing the old one, I ordered a new tank for about $750.00 from Catalina Direct - right at Christmas time too! Ugh!
The previous owner had removed the tank before and made some really shady repairs.
No wonder it leaked.
I looked at the hull and saw the black, tar-like substance - this must be the left from the very slow diesel leak I would suspect that other see as well.
Anyways, there's a high spot on the hull that I am concerned with touching the tank.
I was thinking I would fiberglass the bottom of the new tank to prevent corrosion as well as add abrasion resistance.
Also, what about lifting the tank off the hull?
What would be a good material that wouldn't trap moisture and would prevent chaffing too?
A dense foam? Rubber feet?
Any comments are appreciated.
Mitch
1986 Catalina 36 MKI
S/V "Blessing"
Kema, TX
Hull: #584
M25 w/ Oberdorfer Conversion
Mitch
If you look at the pictures I posted the tank is sitting on a old bath towel on the floor. I used the towel to slide the tank over to the stair. I covered the stairs with bath towels and the companionway. I lifted the tank up to the top step and set it down. It just fits though the companionway. So I just tilted it out into the cockpit. I just reversed the process to return it to resting spot. I did do extensive cleaning while the tank was out.
Capt Bob
Actually that might not be a problem for you as the new tank is rectangular, not tapered to follow the bilge like the OEM. You will need to prop up the one end by the keel bolt so that the tank sits level. I used a piece of pressure treated 4X4 cedar that I had.
After spending $$ on a new tank (as I did), you might consider having the bottom 3rd Rhino coated. It's the stuff they coat pickup truck beds with. It's tough and looks nice on your new tank. See pic in my post above.
Paul & Ann -
"Freestyle" -
1985 C36 #454 -
North Puget Sound, WA
Looks like I am looking at replacing my tank as well, after transporting the boat down to seabrook I noticed it the appears to be more tar like substance every time I get down to my boat. I have two questions 1) did anyone replace the fuel hose, if so do you know the length? 2) in the older boats, mines a 84, was there a fiberglass encased plywood floor underneath?
Pas always any input would be appreciated
Mike Hogan
s/v Ciscocat #226
Mark I XP25, std rig