Hendo's Randall 35 Cray Boat complete rebuild, Perth, Western Australia

[Insequent]

Matt
Here is a pic of the heat exchanger on my starboard engine for the hot water system. The PEX hoses go to the HWS. The black hose comes out of the front of engine block and returns to the rear of the engine block, a dedicated circuit that is not connected to anything else. No pump in it. Both black hose 3-4 ft. You can see an aquastat on the heat exchanger. That turns on the hydronic coolant circulation pump. The full heating system schematic is in the pdf.

As I mentioned earlier, I can get hot water from Raritan HWS heater element, the Webasto hydronic circuit, or the engine. The schematic shows that I have a 'summer loop'. What this means is that I can run the Webasto to get hot water without heating the whole boat.

Another item on the schematic that I should explain is the auxiliary heater tank. It has a 240V element also. This is used when at the dock on shore power, in winter. It provides about 5-7° of heating for the boat without running the Webasto diesel unit. It was installed to avoid running electric fan heaters when not on board, as they can be a serious fire hazard.

The guys at the PT Shipwright's Co-Op really know their stuff, and my boat's heating system design and installation is first class. Of course now I am Queensland I don't need to heat the boat very often.

 

[Peter B]

Hi peter.
Thanks for the post. I see your point and will reconsider as suggested. I have a 240vac power point in the engine room. I’ll put a plug on the end of the heating element cable and plug it in but leave it turned off. Can always run down and flick it on like you suggested. Thanks for that.

Do you have any pipework pics of how the engine coolant pipework comes off the engine and into the hot water system? All of my engine hoses are rather big in comparison to the inlet on the system.

Matt, I can't find any shot of my engine that shows the in and out of the coolant supply as it runs through the hot water heat exchanger. However, from memory there was a 12mm (approx) hose outlet set into the larger diameter water hoses roughly either side of the coolant header tank. Something like that would definitely work, just pressurised from the water pump.

 

[Hendo78]

My Webasto hydronic heating system has a circulation pump and that takes the coolant through the hot water heater. I think its the Stbd engine that has the water heating loop, and it would be about 9ft away from the hot water heater and have a longer hose (PEX) run. I'll check soon.

Ah ok cool thanks for the info mate.

 

[Hendo78]

Matt, here is a pic of my tie in for water heating, although your engine is unlikely to have the same fittings. It’s the blue and black 1/2” ID hoses on bottom right. The take off is from the upstream side of the thermostat housing.

Make sure you install an isolation / bypass manifold in case you develop a leak in your coolant lines.
If possible, run your coolant lines on a steady downhill slope to the heater to avoid any air locks in the system. Also an engine coolant top up reservoir is a good idea if you don’t already have one. View attachment 84061

Sweet thanks for the tips mate. I have to run uphill unfortunately. The tank will be about 4-4.5mtrs from the engine. Yep have one of those reservoirs fitted. Figured it was a good thing to have.

 

[Hendo78]

Matt
Here is a pic of the heat exchanger on my starboard engine for the hot water system. The PEX hoses go to the HWS. The black hose comes out of the front of engine block and returns to the rear of the engine block, a dedicated circuit that is not connected to anything else. No pump in it. Both black hose 3-4 ft. You can see an aquastat on the heat exchanger. That turns on the hydronic coolant circulation pump. The full heating system schematic is in the pdf.

As I mentioned earlier, I can get hot water from Raritan HWS heater element, the Webasto hydronic circuit, or the engine. The schematic shows that I have a 'summer loop'. What this means is that I can run the Webasto to get hot water without heating the whole boat.

Another item on the schematic that I should explain is the auxiliary heater tank. It has a 240V element also. This is used when at the dock on shore power, in winter. It provides about 5-7° of heating for the boat without running the Webasto diesel unit. It was installed to avoid running electric fan heaters when not on board, as they can be a serious fire hazard.

The guys at the PT Shipwright's Co-Op really know their stuff, and my boat's heating system design and installation is first class. Of course now I am Queensland I don't need to heat the boat very often.

Holy cow that’s a decent unit. Here I was panicking about a silly ol hws tank haha.

Hahaha yeah not now it’s summer for us mate. You’d be looking for the AC switch I suspect.

 

[Hendo78]

Matt, I can't find any shot of my engine that shows the in and out of the coolant supply as it runs through the hot water heat exchanger. However, from memory there was a 12mm (approx) hose outlet set into the larger diameter water hoses roughly either side of the coolant header tank. Something like that would definitely work, just pressurised from the water pump.

All good Pete. Thanks mate.

 

[Hendo78]

This afternoon I fitted the accumulator tank and ran the cold water lines through for the kitchen, en-suite and shower.

Then I cut the line coming from the back of the water pump and took a section so I can get some hose fittings matched up to it so tomorrow I can fit the Hot water tank and connect it all up.

Pretty good afternoon

 

[Lou_tribal]

I would suggest you to use some rubber washer/pad under your pump, this help a lot to absorb vibrations, well at least it did make a big difference for my jabsco pump.

L

 

[Hendo78]

I would suggest you to use some rubber washer/pad under your pump, this help a lot to absorb vibrations, well at least it did make a big difference for my jabsco pump.

L

Yeh the pump has rubber grommet feet that the screws go through thanks for the tip.

Speaking of vibrating, does your engine sit on rubber engine mounts or fixed straight to the engine beds ? Mine bolts straight to timber beds like it did when it was first made. I’m thinking I should check out the timber beds and insert engine mounts.

 

[Lou_tribal]

Mine is mounted on mounts bolted to the bed. Not sure if they have rubber pads or not, to be honest never checked the mounts in details beyond checking for corrosion and that everything was tight. I don't have any pic showing the mounts.

L

 

[Hendo78]

Mine is mounted on mounts bolted to the bed. Not sure if they have rubber pads or not, to be honest never checked the mounts in details beyond checking for corrosion and that everything was tight. I don't have any pic showing the mounts.

L

Cool thanks mate

 

[Hendo78]

The hot water tank is in the boat ... yeew.!! Just need to finish plumbing it into the engines coolant system, run a cable for the 240v 1200w heating element and run the cold water line to it and we’re good to go.

 

[Lou_tribal]

I am amazed to see how much space you have to work! I wish I had so much!

If I can risk another suggestion, I would double clamp fittings on soft hose so to reduce the risk of having one popping up under pressure as this is not an enjoyable experience ( don't ask how I know ).


L

 

[Art]

Another SPLASH step getting completed! YEA!!

 

[AusCan]

Sweet thanks for the tips mate. I have to run uphill unfortunately. The tank will be about 4-4.5mtrs from the engine. Yep have one of those reservoirs fitted. Figured it was a good thing to have.

My Kuumo water heater installation manual says that the heat exchanger port on the HW tank ( or temperature control valve if equipped) must be lower than the coolant outlet on the engine.

Do you have any other options for mounting the HW tank?
It might be worth checking with your tank manufacturer before you get too far into it.

Edit - I see that I’m too slow in my reply Matt. You’re unstoppable.

 

[Art]

My Kuumo water heater installation manual says that the heat exchanger port on the HW tank ( or temperature control valve if equipped) must be lower than the coolant outlet on the engine.

Do you have any other options for mounting the HW tank?
It might be worth checking with your tank manufacturer before you get too far into it.

Edit - I see that I’m too slow in my reply Matt. You’re unstoppable.

Look... Up in the Sky! It's a bird, it's a plane... NO!! It's Super Matt; disguised as a human boat rebuilder!!!!!!!!!!!! :lol:

 

[Hendo78]

My Kuumo water heater installation manual says that the heat exchanger port on the HW tank ( or temperature control valve if equipped) must be lower than the coolant outlet on the engine.

Do you have any other options for mounting the HW tank?
It might be worth checking with your tank manufacturer before you get too far into it.

Edit - I see that I’m too slow in my reply Matt. You’re unstoppable.

Lol ... I did check the installation and the uphill mounting is fine under 90° so I think I’m good.

 

[Hendo78]

Look... Up in the Sky! It's a bird, it's a plane... NO!! It's Super Matt; disguised as a human boat rebuilder!!!!!!!!!!!! :lol:

Lol

 

[Hendo78]

Well the hot water system is plumbed in. Just need to top up the Engine coolant and then hardwire the heating element and she’s done. One more task closer to the July launch ...

 

[OldDan1943]

Well the hot water system is plumbed in. Just need to top up the Engine coolant and then hardwire the heating element and she’s done. One more task closer to the July launch ...

Then paint the hull, put it in the water and clean up your yard mess. That will make the owner happy.
Wife excited about you being "almost" finished?

 

[Art]

Then paint the hull, put it in the water and clean up your yard mess. That will make the owner happy.
Wife excited about you being "almost" finished?

She get thaaaat excited when you're "almost" finished? :lol:

 

[Hendo78]

Then paint the hull, put it in the water and clean up your yard mess. That will make the owner happy.

Wife excited about you being "almost" finished?

Lol I’m painting through feb so starting in a few weeks. I’ve been given till July so I’ll use that time up.

Yeah flic is excited to see this wrapping up and that we can pet her to use and is proud of me for sticking to it and finishing it off what I started so long ago. I’m getting excited too. I’ll be relived when I she how she sits. Hopefully she won’t sink.

 

[Art]

Lol I’m painting through feb so starting in a few weeks. I’ve been given till July so I’ll use that time up.

Yeah flic is excited to see this wrapping up and that we can pet her to use and is proud of me for sticking to it and finishing it off what I started so long ago. I’m getting excited too. I’ll be relived when I she how she sits. Hopefully she won’t sink.

Excited for sure! She'll sit fine. Ballast may need adjustment... then again... knowing your smarts... it may not!!

 

[OldDan1943]

She get thaaaat excited when you're "almost" finished? :lol:

Of course, when you are hanging around the house all the time, wifey may get tired of you being there. SMILE
You can jump on the boat and disappear until she calls you and tells you, 'it is safe to come home.'

 

[Art]

Of course, when you are hanging around the house all the time, wifey may get tired of you being there. SMILE
You can jump on the boat and disappear until she calls you and tells you, 'it is safe to come home.'

Word "safe" can be a slippery slope!!!

 

[OldDan1943]

Word "safe" can be a slippery slope!!!

You mean, "Bait and switch" or "get him within gun range"?

 

[Crusty Chief]

Great progress Matt, u da man!

The hot water system I have is pretty complicated as we have shore AC power, Hydronic heat and Main engine. Aquastat’s, heat exchangers, manifolds, circ pump and so on. So dont think I can help on your system much.

Sorry to hear about your eviction notice and hope your able to get as much done prior to splash day. The big stuff is the most important as the trip down docks and such to the boat gets old real fast.

Keep up the enthusiasm and you’ll be enjoying her on the water all too soon!

Cheers Mate!

 

[Hendo78]

Great progress Matt, u da man!

The hot water system I have is pretty complicated as we have shore AC power, Hydronic heat and Main engine. Aquastat’s, heat exchangers, manifolds, circ pump and so on. So dont think I can help on your system much.

Sorry to hear about your eviction notice and hope your able to get as much done prior to splash day. The big stuff is the most important as the trip down docks and such to the boat gets old real fast.

Keep up the enthusiasm and you’ll be enjoying her on the water all too soon!

Cheers Mate!

Thanks crusty. I’ll keep going and do what I can

 

[Hendo78]

Okie dokie well I got a bit done today. Cut an access hole in the floor, fitted some pvc pipe for the water pipe work and the sink drain to pass through. Ive done it under where the kitchen will go not in the walls in case anything happens and I need to access it. I then plumbed in the kitchen pipe work and plumbed in the ensuite pipe work and stopped at the shower because I need a PEX socket to hose barb so I can join the pipe work together and finish the curcuit. I ran the engine and topped up the coolant. The hoses to the water heater from the engine got nice and hot so I’m glad the exchanger is working. I then wired a lead from the engine room power point to the heating element of the HWS incase I need to use it and can’t run the engine or if I’m in a marina and have access to 240v shore power. Once that was done I split the starter bank batteries to 3x100ah for starting then patched in the remaining 3 batteries in to the house battery bank giving me 9x100ah batteries for the house bank but housed in two separate boxes for boat trim

 

[Art]

Complicated - Well Done... Really Cool!!