[meuritt]

I have an on demand water heater on board, propane. It's been there for 36 years. Yesterday, I had a propane technician check it out and pronounced it a safe working appliance, so now, to make the insurance company happy, I need to construct a hood and install a vent overhead.

First thought is stainless construction, but except for the galley sink, nothing on the interior is stainless, either bronze, teak or white paint. As an alternate possibility, what if I had the device built of sheet metal and powder coated.

I know powder coating stand up to heat well and the powder coat on my bicycle has likewise done well in rain, does anyone have any idea how it does in the marine environment?

a side note, I find it very curious that the stove/oven has three unvented propane burners that pose no problem from the insurance companies point of view, the only problem burner is the midships mounted, less than 4' away water heater. it is their insistence that the vent be installed.

Mike
San Rafael, CA
Banjer 37

 

[timebandit]

Powder coating is a plastic powder that is melted. I dont know at what temp it will remelt.

If resurch proves powder coating not able to hold up the heat there is a place that ceramic coats auto headers inside and out that will handle the heat no problem.

 

[merc2dogs]

I could never grasp that myself. A water heater's burner is not much larger than a stove burner, and much smaller than most oven burners, yet that water heater, and furnaces need to be vented

It was explained to me a while ago that stoves are manually operated, water heaters kick on automatically at random times.

Different powder coats do melt at various temps, think the most heat resistant (after initial set) is the thermoset type as it actually changes it's composition during the original bake. The other type (thermoplastic?) essentialy just melts together with no chemical changes in it's makeup, so the melt temp remains the same at all times.

There are a LOT of easily applied ceramic coatings available for home application, satisfaction depends a great deal on prep.

I experimented with lots of different high temp paints over the years (motorcycles primarily) and have been satisfied with a couple.

But the best thing I've found to make any of them last (and it looks good alone) for cycle headers is not intended as a 'paint', it's simply phosphoric acid that's sold in auto stores as a rust stop treatment. Simply clean the metal, lightly scuff it and spray with the rust-stop. Rust will turn to a very hard black oxide that simply will not burn off. Headers here have just over four years on the rust-stop, and still look good.

Picasa Web Albums - ken - bike

Don't mind the seat, it was a quick slap together so I could ride while I built a new one.

If you use a ceramic paint and the part is small enough, bake it in the oven before use, most ceramic paints are VERY soft before they cure, relying on the heat from use to cure it will often result in uncured areas because of uneven heating
I built an oven out of drywall and old stove elements to cure larger parts

Ken

 

[AjariBonten]

I find it very curious that the stove/ oven has three unvented propane burners that pose no problem from the insurance companies point of view, the only problem burner is the midships mounted, less than 4' away water heater. it is their insistence that the vent be installed.

Same thing in homes. As said above, I'm pretty sure it's the fact that a stove is (should be) used in a deliberate manner, under observation, and is used while awake.

A water heater is automatic ( I know, an on-demand heater is a little bit different) may operate while the crew is sleeping, and is not generally in an observable location.

 

[travler37]

I have played with p-coating.
Bought this.

Harbor Freight Tools - Quality Tools at the Lowest Prices

A small oven that i use for gee..small parts.
That said there always seams to be a line of people that want me to cook parts...

This process makes some amazingly flexible coatings...and some opsys that will not be talked about.I have never had anything i have coated in salt water but a experament we did boaring out a prop and coating it.Then sleaving to take up the slack of coat.This is freshwater on a dink that stays in the water for season.After 2 years in freshwater without a cleaning and generally being abused the p-coat is still on prop except for aprox1\2 in around blades.No marine growth after running prop for a minute.Thing about p-coat is it sheds or does not attract in the water life.No slime comparing prop hub to lower untit of motor.
Sorry,is to darn cold to go take a pic.4f...brrrr.
Prep work is the key.If you want a good looking job do some reaserch if your going to do it yourself.Your oven at home probably wont be able to substain the heat eavenly to do a good job...Life Hint

That said making a sheetmetal hood and paying someone else will work.Making smaller pices and popriviting them would work if you want to play and do the learning curve and do it yourself.

Am currantly thinking on making my own long thin oven and doing grab rails.Hate to pay someone else whan i can screw it up myself.

My Thoughts
Mark

 

[travler37]

Ps on home coating,
I use a 50amp 12v charger between my gun and surface.Makes a good smoooth coat.
Mark

 

[sailingdog]

As Ajari pointed out, it has to do with the fact that stoves/ovens are generally used with a person attending them. The flame is not automatic and does not come on by itself. A water heater is a greater fire/explosion/carbon monoxide hazard for those reasons—since it often runs unattended and can come on by itself. If you have a propane powered water heater aboard, please make sure you have a propane fume detector that can kill the solenoid if it detects propane.

 

[travler37]

As Ajari pointed out, it has to do with the fact that stoves/ovens are generally used with a person attending them. The flame is not automatic and does not come on by itself. A water heater is a greater fire/explosion/carbon monoxide hazard for those reasons-since it often runs unattended and can come on by itself. If you have a propane powered water heater aboard, please make sure you have a propane fume detector that can kill the solenoid if it detects propane.

I do not agree,
Sadly the insurance companys dn a boat if you are going to use PROPANE you turn the bottle on.If not you turn it off.Same for stove/lights/heat/hotwater........

Is basically another out for them............

My Thoughts
Mark

 

[meuritt]

Even though the boat is old, we have sniffers on board and the bilge the propane might leak into is isolated from the bilge with the engine. The sniffer is part of the electric valve attached near the regulator in the properly vented propane locker

Basic safety is routine with the propane appliances on board, the stove, water heater and wall heater, if we are on the boat and might want to use gas, the bottle is turned on. If we actually use the gas, two switches must come on. I do need to test the sniffer unit itself, I know they have a life span.

I was at the boat last night and actually got to wash dishes with hot water. While the water heater is old, it is a European home style common back then. Our operation will be to light the pilot when we want to use the heater, first position of the valve is pilot, then turn to second, operating position, turn on water and the main burner comes to life. Turn off water, flame goes out immediately, leaving the pilot on. All done with hot water, turn off pilot.

In fact, when we are in motion, bottle is turned off. Is this a common practice?

Thanks for the suggestions

mike
San Rafael, CA
Banjer 37

 

[sailingdog]

...In fact, when we are in motion, bottle is turned off. Is this a common practice?

If it isn't, it should be. The gas should be shut off whenever you're not actually using it IMHO.

 

[donhaller]

I'm not sure if the OP's question was answered or not about Powder Coating for the hood. I am sure that it will be more than fine for your hood. I often have engine parts for my car powedercoated without any probems so far, including intake manifolds which are directly attached to the cylinder heads.

I'm not sure how well it will do in a humid salt air environment, but I would assume as good or better than a painted surface. Of course S/S would be a better alternative if you like the finish and the cost is in the range you want to spend.