Bav 36 attaching Marine Ply to GRP (Planar Diesel Heater Project)

[dcreedon]

Happy New Year. I need some help on a small project I'm working on.

I'm looking to fix a small piece of marine ply 20cm x 20cm to the inner hull floor of my boat (GRP) near the transom, directly under the existing reinforced rear step.  I need the ply to be waterproof and have zero risk of coming loose from the GRP. :-)

I'll be attaching a Planar marine diesel heater to a mounting bracket attached to the marine ply.

I think the approach (after research) would be to coat/soak the ply in polyester resin and once dry use Chopped Strand Matting and epoxy resin to attach it to the GRP.

or

just go with the polyester resin for soaking the ply and attaching the ply to the GRP using Chopped Strand Matting and polyester resin.

Thoughts on the above appreciated....

Thanks

Damian

[Stevie H]

Is there a reason you want to fit the heater in that location? On my B36 the Eber heater, which I understand was professionally fitted when the boat was new, is mounted on a bracket attached to the ply bulkhead between the starboard stern cabin and the lazarette void (but could have equally been fitted on the port side)

[dcreedon]

Thanks I’ll check it out. Don’t suppose you have any pictures of the install ?

[symphony2]

You would be in serious trouble if that area of the boat was so wet as to rot marine ply - you have ply bulkheads with exposed grain in that area already. A simple and effective way of attaching ply pads is to use one of the "grab" type of adhesives such as "Sticks like S**T " and paint the pad with a bilge paint such as Danboline. However, as suggested it is better to mount the heater on an existing bulkhead if you can.

[nightowle]

I'm not contradicting the others here recommending aft starboard or port side installation because our Espar is itself installed on the starboard side.  But when it was serviced a year ago and reported to be extremely coked up the mechanic said it's better to install a diesel heater more amidship if possible.  Of course, I have no idea if this holds true for a planar style.

[IslandAlchemy]

Forget using epoxy for a start.  Just use polyester resin for all of it.

Laminate the ply in place with chop-strand, and leave it at that.  It's only the bottom of the ply that might get wet, and your lamination will have sealed this.

[symphony2]

Not sure how it is going to get wet in that location - if there is a possibility of sufficient water to rot marine ply then you would not want to mount a heater there either! The only possible sources of water in any quantity are from the shower and its piping or the exhaust. If either of those are leaking you would know about it pretty quickly and fix it. If the idea of grab adhesives does not appeal, then a fast curing epoxy is an alternative - the pad only needs to be firmly attached to the GRP.

[dcreedon]

Thanks for the input guys, I’ll check out the bulkhead before committing to attaching to the hull. Agreed on the water, if water reaches the heater in any significant amount I’ve got bigger problems like sinking :-)

[ICENI]

As far as Attaching Items using plywood, having built my last boat from a bare hull, bonding the bulkheads engine mounts and cabin furniture to the hull the points to note are as follows:-

1  Abrade the glassfibre removing any Gellcoat and when that has been done dust the area well.

2 It is important to mix the polyester resin and the catalyst correctly.   Mix well and take note of the ambient temperature and do not mix too much.   Wear disposable gloves

3 Cut to size the glassfibre ( If you have not already purchased the glassfibre, I found that woven rovings easier to use and wetted out easier)

4  Using a pad or something to wet out on (a cheap brush can be used)  wet out the first sheet and apply to the ply and the hull.  Ensure any air bubbles are removed.   Allow to dry as this should take only a few minutes.

5 Build up until the thickness is suitable to hold the unit firmly.

6 Clean the brush etc with Acetone if required.

As far as mounting heaters in a damp marrine environment I would be very careful here.   I mounted my Ebaspacher heater in my last boat in the sail locker and sadly the saline environment  destroyed it after a few years.   I have in my Bavaria an original heater also aft in the sail locker but the Bavaria lazarette seems a lot drier, however I will be keeping an eye on things.

Regarding mounting a diesel heater:-   When I mounted mine I glassed a 25mm thick piece of marine ply to the inside of the hull and made up an aluminium right angle plate to mount the heater on this.   With timber scratch a criss cross pattern using a stanley knife or such like on the side that you are glassing on to, to improve the bond.

I hope the above helps.

[dcreedon]

Hey Chris, thanks for the info really useful. I’ve a mounting bracket coming with the heater so that’s sorted the reasoning behind the location is the ease of access (relatively) and keeping the exhaust run to a minimum.

[ICENI]

On my Bavaria, the original fitted heater is in the Lazarette, aft at the rear of the locker.   The exhaust outlet fitting is near the deck shower hose fitting on the transom so is, as you say, quite short.  On my last boat we had taken on seawater in bad conditions over the side and I suspect that was the reason for the demise of the heater!   On your Bavaria, the locker is much better protected by the locker lid than on my old boat.

One other point -  ensure your cables are heavy enough as the electronics of the heater will shut down when the input voltage drops to near 11.5 volts or thereabouts.  At start up, when the glow plug is on on the heater, I try to run the engine.   That is, until the heater has started up and is running normally.
Feed cable diameter and short length is important here both positive and negative.   

[Lyra]

Forget using epoxy for a start.  Just use polyester resin for all of it.

Have to disagree with that. Apart for the cost, which is about double, I find it much easier and friendly to use, and it is the only material I use for wood and fiberglass work.
(I did several boat building projects using epoxy, so maybe I am biased)
Unused epoxy will keep for many years when stored properly, so buying a 1kg kit can serve several projects.
It has no almost fumes - I do not want to think what I would have gone through if I used polyester for mounting my under the deck autopilot
It is true that once you use epoxy you cannot apply polyester on it if required, but epoxy over polyester works fine.

[Holger]

You do not have to glass the piece of ply in place - but certainly you can. Usually, it is more than sufficient to glue the piece of ply in place using thickened expoxy. You can buy thickened epoxy in cartridges which is easy to apply as you do not have to care about the correct ratio of resin and hardener. If you want to seal / waterproof the piece of ply you should use unthickened epoxy rather than thickened epoxy. This seems to be what Bavaria applied to the bulk head in the compartment at the bow where the anchor chain is stored.

On a separate note, I was also wondering whether the location you identified is good. On our 37 (2006) the (Webasto) heater is mounted at the top of the aft bulkhead on the starboard stide. 

[dcreedon]

Thanks , due to lockdown I haven’t been able to check out the bulkhead location yet but it would be the preference if it fits

[Salty]

I sold my B36(2002) a few months ago, so cant provide any photos of the installation. The boat had been one which in addition to the main saloon, it also had three sleeping cabins, one forward and two aft. The Eberspacher heater had been fitted inside the lazarette on the aft side of the port cabin aft bulkhead, and just above the removeable door from the port cabin into that space.
The heater was set up so that the discharges of warm air duct and the exhaust hose, were both at the starboard end of the heater. The exhaust gas hose curved upwards and passed close over the top of the heater, passing along the bulkhead to the port end of the heater where it then curved across to the inside of the boats port side hull where it continued curving downwards and aft before arrival at its overboard stainless steel outlet.
The warm air duct from the heater curved down along that bulkhead, past the starboard side of the removable access door to a point where it was below the level of the board forming the base of the port cabin bunk. There the warm air duct curved forward passing under the bunk where it travelled to the forward end of the bilge space below the bunk. At the forward end of the bunk a “Y” branch was fitted to an outlet allowing some heat into the port aft cabin. From the other leg of the “Y” branch the heating duct curved across just aft of the engine space to the starboard side where another “Y” branch was fitted with an outlet to warm the aft starboard cabin. Again, from the remaining leg of the “Y” branch the heater duct curved forward, passing through the bilge areas under the starboard cabin bunk and then forward under the aft starboard cabin seat area and under the hanging locker where it then passed through the transverse bulkhead and into the main cabin. An outlet was provided under the seat at the chart desk, and that was as far as the heater duct went.
It had been my intention to extend the heating duct to go further forward through the bilge areas of the battery locker and on into the forward cabin, but despite ten years of owning the boat, and being a hardy type, I just never got around to it.

[catlotion]

not sure if relevant as I'm not familiar with Bav 36 locker/void configuration but here's my install on my 30 Cruiser.   I spent some time deliberating on location and initially intended bonding some wood to the hull but then decided to mount a piece of oak floorboard to the aft cabin bulkhead and bolted heater to that (the photo is taken looking aft).   I have yet to fit air input duct from cockpit but will do when I can get back to boat...   

There's always a compromise on these installs but I was trying to a) minimise bends to output duct and b) ensure that the exhaust was kept clear of anything.  I did consider getting the boat yard to install but they would have just plonked it in the locker rather than the void and having had to do that on a previous Beneteau I knew that is far from ideal as you have to be careful not to store things near the exhaust.

The compromises I have accepted are that the fresh air input duct bends quite a bit and the exhaust skin fitting is above the heater (with big swan neck though) but I thought these were preferable to bending output duct too much.

[dcreedon]

Ok so got it attached to the port side lazarette bulk head on the transom side. Two bits of marine ply on either side of the bulkhead to give a bit of support.  Port side was easiest as there was cabling on the starboard side. Also the run for the hot air was much easier on the port side due to the water heater being on the starboard side.

I’ve got all the hot air piping done with one hot air outlet in each of the port and starboard aft cabins. One outlet at the chart table , one further down the starboard side seat and one in the forward cabin.

[DaveNZ]

I am about to embark on doing the same install on a B34 2002 and would love to see some more photo's of how your project has progressed! Appreciate if you could post them.

[dcreedon]

Hi Dave
 I’ll do you one better and can arrange a zoom call with you to discuss the install.

I’m nearly finished , just the fuel line to connect , and connection to the battery.


Damian

[dcreedon]

Right everyone, install finished, and up and running. Boat did not end up like a viking funeral.

In summary it required:

1) New hole in fuel tank for stand pipe.
2) Mounting heater on port side transom lazarette bulkhead.
3) Drilling a hole in the transom for the exhaust
4) Running all the 90 and 60 mm heat ducting, installing the vents (more drilling)
5) Running the wiring, extending the power harness by half a meter, some yoga/gymnastics.
6) A new pair of underpants on standby when I switched it on.

What I learned/advice:

1) I got my ducting measurements correct. Ran the ducting down the port side and then through the engine bay to starboard cabin and onwards to saloon and forward cabin.
2) Needed to extend the controller harness and power harness.
3) Got a silenced exhaust that required only two connections. One to the exhaust through hull and one to the heater. Instead of the one that came with it that would required four connections.
4) Used exhaust cement to join the exhaust to the through hull and heater.
5) Tried to prime the fuel line first with a syringe, then with sucking, then  with a 12v pump from lidl. After checking that fuel was not getting beyond the pump I just switched it on a couple of times after the error 13 (all attempts to start failes, check fuel supply) came up. I could hear the pump going and after a while could see the diesel on its way to the heater.
6) I started the heater without the fuel line attached, thinking that the pump may need to be "active" to allow my sucking/pumping attempts to prime the fuel line to work (it didn't) see #5.  The exciting thing about doing this was I could see smoke coming out of the heater "mild f**king" panic ensued until I could see it was coming out of the fuel pipe inlet. Figured out that it was some crap burning off in the chamber and making its way out. Phew, I did flap for a few seconds trying to figure out how to turn off the heater as it is directly connected to the battery. Pulling the fuses solved that.
7) I will be installing an on/off switch.
8) I had a fire extinguisher handy and had installed two CO detectors, one in the transom above below the heater and just above the hatch and one outside the port side cabin.
9) I installed a fuel filter in the fuel line, nothing fancy https://www.tigerexped.de/Fuel-pre-filter-for-diesel-and-petrol-heaters but I did require extra fuel line hose and hose clips as the heater only comes with the required amount. I bought about 1.9M more than I needed if anyone in southern Ireland wants some (the fuel line that comes with the heater is fine)
10) I bought insulating material for the hot air ducting, works well
11) Used this on fuel tank/stand pipe gasket - Blue Hylomar Gasket Size: 100g
12) Used Permatex Gasket Maker Ultra Copper Max Temp on both sides of the gasket for the exhaust through hull.
13) I used a laser thermometer (Lidl) and my finger to check surface temperatures of pipes etc..
14) I secured the exhaust to the hull using Tec-7 adhesive, two pieces of wood and the exhaust brackets that came with the heater.

I ran it first for 30 minutes at full temp to burn it it.
I then stopped it and restarted it and ran it for two hours checking surface temperatures etc...

I have photos and video and will upload in a bit.  Any questions or specific info needed please let me know.


And .. measure twice, think about it, measure again, and then cut.



Useful Sites
1) https://planarheaters.co.uk/ For those outside of the EU
2) https://www.svb24.com/       Ultra efficient :-)
3) https://www.tigerexped.de/   sometimes cheaper than SVB