New TomCat 25
- Thread starter TyBoo
- Start date
Hi, Paul
Sorry you missed the Christening. Let me know when you're in the area and we'll hook up.
About the compressor situation, it's not the heat of the compressor anymore. The experts at Compressed Air Specialties checked it all out over several days and gave it the green light as it is. Recommended changing oil every 50 hours.
The problem is the heat generated by the exhaust from the 9.0 Honda engine that drives the compressor. I ran a stainless flex pipe from the muffler outlet to a fitting on the stb stern just below the rub rail and covered it with a fiberglass sock. After 15 minutes of running the engine with a load the heat had worked its way along the pipe to the hull fitting and was extremely hot, enough to damage the fiberglass if left longer.
I've checked with several knowledgeable folks and they seem to agree that a water jacket is the best solution. I may be able to supply it from the existing raw water washdown. The water would exit through holes drilled in the back of the hull fitting, sending water over the last 3" of the exhaust pipe and on the inside surface of the hull fitting. There's a ss pipe fab shop in Long Beach that can do it.
I'll take some pics today and it will become clearer.
Bob Cat
Sorry you missed the Christening. Let me know when you're in the area and we'll hook up.
About the compressor situation, it's not the heat of the compressor anymore. The experts at Compressed Air Specialties checked it all out over several days and gave it the green light as it is. Recommended changing oil every 50 hours.
The problem is the heat generated by the exhaust from the 9.0 Honda engine that drives the compressor. I ran a stainless flex pipe from the muffler outlet to a fitting on the stb stern just below the rub rail and covered it with a fiberglass sock. After 15 minutes of running the engine with a load the heat had worked its way along the pipe to the hull fitting and was extremely hot, enough to damage the fiberglass if left longer.
I've checked with several knowledgeable folks and they seem to agree that a water jacket is the best solution. I may be able to supply it from the existing raw water washdown. The water would exit through holes drilled in the back of the hull fitting, sending water over the last 3" of the exhaust pipe and on the inside surface of the hull fitting. There's a ss pipe fab shop in Long Beach that can do it.
I'll take some pics today and it will become clearer.
Bob Cat
Just posted some pics of the exhaust canundrum.
Possible solution: Get a slightly larger thru hull fitting and tig in a 22mm ss hard exhaust pipe back to a flex joint at the engine. Drill about 6 holes in the space between the outside of the 22mm pipe and the outer edge of the thru hull for water to shoot out and drench the inner exhaust tube in the external thru hull. Tig a jacket sleeve over the exhaust tube, connected inside the outside threaded thru hull and back as close as possible to the flex joint at the engine muffler. Suspend and hold firmly with brackets. Supply sea water from the raw water washdown system at 3.5 gpm (tested today).
Comments and suggestions welcome.
Bob Cat
Possible solution: Get a slightly larger thru hull fitting and tig in a 22mm ss hard exhaust pipe back to a flex joint at the engine. Drill about 6 holes in the space between the outside of the 22mm pipe and the outer edge of the thru hull for water to shoot out and drench the inner exhaust tube in the external thru hull. Tig a jacket sleeve over the exhaust tube, connected inside the outside threaded thru hull and back as close as possible to the flex joint at the engine muffler. Suspend and hold firmly with brackets. Supply sea water from the raw water washdown system at 3.5 gpm (tested today).
Comments and suggestions welcome.
Bob Cat
C-Brats
Posted some pix of the latest work on Discovery. Dixie sewed, and I installed privacy window coverings. Will come in handy overnighting in marina's, also for sleeping if we get to Alaska this June and July. We finally got the name graphics on the boat. Also mounted a carrier for the Honda 2HP motor for the inflatable. I am working on a carrier mount for the inflatable. It will be above the swimstep and Armstrong Brackets. Not perfected yet. Working in mild steel on a prototype. Will make it out of stainless when a final version is workable.
Brent
Posted some pix of the latest work on Discovery. Dixie sewed, and I installed privacy window coverings. Will come in handy overnighting in marina's, also for sleeping if we get to Alaska this June and July. We finally got the name graphics on the boat. Also mounted a carrier for the Honda 2HP motor for the inflatable. I am working on a carrier mount for the inflatable. It will be above the swimstep and Armstrong Brackets. Not perfected yet. Working in mild steel on a prototype. Will make it out of stainless when a final version is workable.
Brent
Fishtales":1mlqmltv said:
Me too!
Bob, doesn't the engine which drives the compressor have oil in it? Couldn't you put a remote oil cooler on it so it doesn't run so hot? But I think what you are thinking is probably the better fix as it addresses the hot exhaust tube directly. I hope you get it figured out. Also .. I appreciate the offer, that's generous of you. Perhaps in the next month or two we can make it up there to meet you guys and go out for a dive or two
Bob Cat,
I have no experience with compressors, but have you investigated using some form of double-wall pipe? Something like those used on wood stoves which depend on an airspace instead of insulation. If something like that could be adapted to fit your muffler outlet it would be much simpler that plumbing a water cooled system?
I have no experience with compressors, but have you investigated using some form of double-wall pipe? Something like those used on wood stoves which depend on an airspace instead of insulation. If something like that could be adapted to fit your muffler outlet it would be much simpler that plumbing a water cooled system?
Brent, I don't see the pics in your album.
Ken, some more experts stopped by today for another opinion. Consensus is that air alone won't do it. It will have to be water cooled. Fortunately, I have water available from the raw water washdown pump at 3.5 gpm. Waiting for a call back from the fabricator to discuss options.
Bob Cat
Ken, some more experts stopped by today for another opinion. Consensus is that air alone won't do it. It will have to be water cooled. Fortunately, I have water available from the raw water washdown pump at 3.5 gpm. Waiting for a call back from the fabricator to discuss options.
Bob Cat
Sorry, Bob Cat, I can't offer much advice on your heat problem, but it sounds like you are on the right track. I will say that you probably don't want to run the washdown pump for 15 minutes at a whack. You need volume instead of pressure anyway, so a vane type pump like the Water Puppy dedicated to the job will probably last a whole bunch longer and do a better job for what you need. That compressor with the Honda wouldn't happen to be belt driven, would it? You have it made if it is.
You sure have a cool boat! I have been watching all your progress posts and am really impressed by the thought and planning that went into getting all those features on board, functional, and out of the way. You and Les are my latest idols!
You sure have a cool boat! I have been watching all your progress posts and am really impressed by the thought and planning that went into getting all those features on board, functional, and out of the way. You and Les are my latest idols!
Hi, Mike
Thanks for the supportive thoughts.
The compressor is belt driven off the Honda, but it is covered with a guard, impossible to see and get to if service is required without removal of the compressor from its bed.
The gpm rate for the washdown is 3.5. Isn't that enough volume? I'm hoping the fabricator, who specializes in marine exhaust systems, will be able to fill in the specs. More advice requested. I don't mind making another thru hull if it leads to a 120% resolution of the problem. Are washdown pumps short-lived?
Bob Cat
Thanks for the supportive thoughts.
The compressor is belt driven off the Honda, but it is covered with a guard, impossible to see and get to if service is required without removal of the compressor from its bed.
The gpm rate for the washdown is 3.5. Isn't that enough volume? I'm hoping the fabricator, who specializes in marine exhaust systems, will be able to fill in the specs. More advice requested. I don't mind making another thru hull if it leads to a 120% resolution of the problem. Are washdown pumps short-lived?
Bob Cat
Your washdown pump is probably a multi-chamber diaphragm pump with lots of moving stuff inside. They make a fair amount of pressure at low volume, and are really intended for intermittent duty. But they are advertised for use as bait tank pumps, so running them for long periods is OK, I suppose, even though they don't have a continuous duty rating. The vane type pump is a more simple design and will move much more water at lower pressure. Most of them (actually the motors that run them) are rated for continuous duty.
This is probably another one of those discussions I should have stayed out of. Your 3.5 gpm washdown pump should provide enough flow for what you want since there will be no real pressure build up. Besides, it is already there and only needs some easy plumbing to use. It's just one of those things that grabbed my attention when I read it. The small washdown pump is made for moving water and making the stream useful after the nozzel, but asking it to just do part of its job for a little longer period shouldn't hurt a thing. A vane pump is made simply to move water, which is what you are after because once the water goes out the end of your cooling tube you are done with it. By giving up the ability to make useful pressure, you get a lot more flow for the same amps. But now that you made me think about it, it does seem to make more sense to use the pump you already have.
See - look at all the time I wasted saying something and then taking it back. Sorry. I could have spent that time looking at your boat pictures again. Or thinking of what all you could do with the free hot water you can make.
This is probably another one of those discussions I should have stayed out of. Your 3.5 gpm washdown pump should provide enough flow for what you want since there will be no real pressure build up. Besides, it is already there and only needs some easy plumbing to use. It's just one of those things that grabbed my attention when I read it. The small washdown pump is made for moving water and making the stream useful after the nozzel, but asking it to just do part of its job for a little longer period shouldn't hurt a thing. A vane pump is made simply to move water, which is what you are after because once the water goes out the end of your cooling tube you are done with it. By giving up the ability to make useful pressure, you get a lot more flow for the same amps. But now that you made me think about it, it does seem to make more sense to use the pump you already have.
See - look at all the time I wasted saying something and then taking it back. Sorry. I could have spent that time looking at your boat pictures again. Or thinking of what all you could do with the free hot water you can make.
Brent and TyBoo,
Found your pics, Brent. Lookin' good! Did you put sunshade material under the solid covers, or solid only?
I'll be moving the trailer brake mechanism soon. Thanks for pioneering that solution!
Mike, my washdown pump is a Shurflo Blaster, not listed as continuous duty in the WM catalog. However, the Jabsco PAR-Max 4 is. I'll do some research on the Jabsco site and possibly change out the pumps.
The things I learn here prove the benefits of membership and participation.
Thanks!
Bob Cat
Found your pics, Brent. Lookin' good! Did you put sunshade material under the solid covers, or solid only?
I'll be moving the trailer brake mechanism soon. Thanks for pioneering that solution!
Mike, my washdown pump is a Shurflo Blaster, not listed as continuous duty in the WM catalog. However, the Jabsco PAR-Max 4 is. I'll do some research on the Jabsco site and possibly change out the pumps.
The things I learn here prove the benefits of membership and participation.
Thanks!
Bob Cat
Steve,
We still have the MaxAir portable compressor. Will carry it in the cockpit, and use it on the swimstep. Like we did on the TC24. Just don't dive much anymore. Seems diving in cold water has lost it's appeal. Maybe plan some time in warmer waters.
Bob,
We just used the Sunbrella fabric for privacy covers. don't know if all that glass will be a sunshine problem or not. Plan to be in the north in summer and south in winter. Maybe the heat will be appreciated.
Brent
We still have the MaxAir portable compressor. Will carry it in the cockpit, and use it on the swimstep. Like we did on the TC24. Just don't dive much anymore. Seems diving in cold water has lost it's appeal. Maybe plan some time in warmer waters.
Bob,
We just used the Sunbrella fabric for privacy covers. don't know if all that glass will be a sunshine problem or not. Plan to be in the north in summer and south in winter. Maybe the heat will be appreciated.
Brent
Happy to report EZLoader is working diligently to resolve the trailer issues. One of their factory people called today with an update and a promise to send improved replacement parts for my winch assy today.
Meanwhile, I'm going to try recovering the boat with the truck farther from the water. This will require more powering up, but will allow the bow to rock up and stern to settle closer to the bunks before pulling up the ramp.
The metal fabricator is making up a 7" water cooled riser connected to the Honda exhaust manifold and running downhill to the hull flange. I'll feed the water from the washdown and we'll all live happily ever after!
Pics when available.
Bob Cat
Meanwhile, I'm going to try recovering the boat with the truck farther from the water. This will require more powering up, but will allow the bow to rock up and stern to settle closer to the bunks before pulling up the ramp.
The metal fabricator is making up a 7" water cooled riser connected to the Honda exhaust manifold and running downhill to the hull flange. I'll feed the water from the washdown and we'll all live happily ever after!
Pics when available.
Bob Cat
EZLoader is talking with CD about a sliprier (sp?) material for at least part of the bunks. They already provide a 2 speed winch that may pull it up. My original winch was beginning to bend and I noticed on Cygnet, the TC24 at the factory, the winch bracket was also bent.
Don't have experience with any power winches,but am willing to look at all options. The bottom line is that the transom must be even with/ or a little forward of the end of the bunks when you pull up the ramp.
Once we have all the front end stuff resolved, I'll take Dive Cat to the scales and see what the tongue weight is.
Bob Cat
Don't have experience with any power winches,but am willing to look at all options. The bottom line is that the transom must be even with/ or a little forward of the end of the bunks when you pull up the ramp.
Once we have all the front end stuff resolved, I'll take Dive Cat to the scales and see what the tongue weight is.
Bob Cat
Captains Cat
New member
Hey Bob, I've got the perfect solution.
1. Move to a Houseboat. :lol:
2. Buy a trailer for your truck to ride on in the water. :roll:
3. Tow it behind DiveCat. :thup
Eliminates lots of house maintenance, winch problems and other stuff.... :disgust :disgust
Seriously, great to hear about all the stuff going on out there, great to meet you at SBS, keep us posted on the boat!!
Charlie
1. Move to a Houseboat. :lol:
2. Buy a trailer for your truck to ride on in the water. :roll:
3. Tow it behind DiveCat. :thup
Eliminates lots of house maintenance, winch problems and other stuff.... :disgust :disgust
Seriously, great to hear about all the stuff going on out there, great to meet you at SBS, keep us posted on the boat!!
Charlie
Just posted pic of Phase I of the TomCat trailer fix. The wire winch cable has bee replaced with a 3" strap and the chain has been shortened considerably. The strap comes off the drum, straight up and over the bar above, then under the roller.
I've put the factory supplied larger backup plate inside the hull for the tow eye. I'll still tie it down from the eye to a couple more places on the trailer frame and tie a hogging line all the way around forward of the cabin.
The roller still needs to be replaced with a flatter polyurethane (clear) type that won't mark or damage the hull. EZLoader is still sourcing that.
I'll take Dive Cat out later this week and check the tongue weight. The ramp recovery strategy is to try it with the trailer higher and winch it into place, allowing the bow to rise and the stern to settle rather than driving up.
Bob Cat
I've put the factory supplied larger backup plate inside the hull for the tow eye. I'll still tie it down from the eye to a couple more places on the trailer frame and tie a hogging line all the way around forward of the cabin.
The roller still needs to be replaced with a flatter polyurethane (clear) type that won't mark or damage the hull. EZLoader is still sourcing that.
I'll take Dive Cat out later this week and check the tongue weight. The ramp recovery strategy is to try it with the trailer higher and winch it into place, allowing the bow to rise and the stern to settle rather than driving up.
Bob Cat
Bob,
We just returned from an 8 day trip to Lake Powell. Great trip, great weather, and a great boat. We did have a little problem getting launched. The ramp was so flat, due to low water, that we had to back way out to get the boat off the trailer. Water was almost to the tailgate before the boat floated. If I didn't relocate the brake actuator, we wouldn't have been able to get launched. The loading was a repeat, but I powered on OK, and only winched the last couple inches.
The only concerns on the trip were that the fish box's take on water and if you store dry items in them, it gets wet. Also I cannot trim the motors so that they don't throw water on each other. The starboard motor throws a stream of water on top of the port motor. If I trim both motors all the way down then it's better, but that's not where the most fuel efficent trim angle is. The sweet spot was at 3800 RPM, with 22 Knots, and just under 5 GPH/motor.
I will post some pix later. Bob, have you had any problems with the motors drowning each other? Not sure that the motors shouldn't be mounted higher.
Brent
We just returned from an 8 day trip to Lake Powell. Great trip, great weather, and a great boat. We did have a little problem getting launched. The ramp was so flat, due to low water, that we had to back way out to get the boat off the trailer. Water was almost to the tailgate before the boat floated. If I didn't relocate the brake actuator, we wouldn't have been able to get launched. The loading was a repeat, but I powered on OK, and only winched the last couple inches.
The only concerns on the trip were that the fish box's take on water and if you store dry items in them, it gets wet. Also I cannot trim the motors so that they don't throw water on each other. The starboard motor throws a stream of water on top of the port motor. If I trim both motors all the way down then it's better, but that's not where the most fuel efficent trim angle is. The sweet spot was at 3800 RPM, with 22 Knots, and just under 5 GPH/motor.
I will post some pix later. Bob, have you had any problems with the motors drowning each other? Not sure that the motors shouldn't be mounted higher.
Brent