more work on the thermostat housing

[supermanotorious]

been a while since I posted about my 94' Four Winns with OMC 3 liter but here I am again. I ordered a new cast housing from ebay which showed less damage than mine. Problem is the housing gets so rusted out it allows water around the t-stat and the engine never gets up to temperature.

So I soaked this new housing in evapo-rust over night and it seemed to work well. My question is how can I coat the inside of this housing to mitigate rust? There is a small bypass tube which would be too hard to powdercoat. I'm almost thinking of getting some tool enamel and dipping the whole unit in there to ensure coverage. What are your thoughts?

 

[supermanotorious]

Considering the Hammerite, inspired by my mechanics

by the way I can watch this guy work for hours

https://www.youtube.com/watch?v=U2jNeObHnZY

 

[itsid]

really? I'm more of a hand tool rescue guy

how about cooking it in linseed oil
for an hour and then hit it with a torch (old school blackening kind of)
that should reduce rust by a fair bit

but then again, maybe that's not the problem at all..
maybe we deal with the side effect here and you could easily ...
IDK replace the broken rubber seal some other place to prevent it
from getting into contact with water *shrugs*

So allow me to ask (I'm not a boat person at all)
Where exactly does it sit on the engine,
if it's the water thermostat (cooling) then
is this a closed or open cooling system?

And if it's the air thermostat then where does the water come from in the first place..
The oil thermostat should also see no water at all if your engine isn't submerged...

I'm a bit baffled
(mainly because I know a shirt from a boat but other than that it just sounds almost alike )

'sid

 

[Flyinhillbilly]

I'm a bit baffled

'sid

Clearly.

I think dipping it sounds like the best option. Given the environment that it lives in I think it should be considered a consumable.

 

[Denny]

Paint it with Glyptol.

Denny

 

[supermanotorious]

this is an open cooling system, water is drawn in motor from the outboard and pumped by an impeller, there is the small bypass circuit that allows a little water to constantly flow through engine block, then when motor gets to temp the t-stat opens and allows full blast water to circulate engine

too difficult to call this part a consumable because it is obsolete

water runs through all channels of this part even though it sits at the front top of the engine

 

[supermanotorious]

I just soda blasted what I could inside the housing in preparation for some coating, I may rinse with paint thinner and let air dry or brake cleaner, then dunk in the solution

 

[supermanotorious]

here is where it mounts to the engine, with the upper housing removed, I took a wire cup to the gasket surfaces, you'll see how mine has so much more wear than the ebay replacement

 

[itsid]

I'm still baffled I'm afraid..
a water containing part designed to rust that easily
is about as good of an idea as filling the fire extinguisher with petroleum.

And while I'm still not a fan of paint (or any non base material fused coat)
inside the cooling system;
I certainly do not have any expertise on boat engines
how their cooling passages are designed, what kind of debris they can tolerate etc...

I'd go with a fused coat (CVD, PVD) ideally but that is expensive to get done;
That's why I'm still for some blueing or blackening solution first, just to see how long it'll last..

Wait?! You said you got a new'ish replacement part, right?
How about you clean the old as good as you can,
then put some spots of paint somewhere,
some powder coat on some other spot,
blacken a bit (linseedoil &heat) and blue (chemical gun blue) some other bit

and drop it in a container with warm salt water for a few days...
see what holds up and what doesn't...
then base your decision on the results?

'sid

 

[supermanotorious]

thats awful sciencey sid LOL

 

[itsid]

yeah I know, sorry Ryan

If I knew what would work for sure, I'd told you right away..
but I simply don't..

My local micro river has a speed limit of 6km/h (4mph)
and the next bigger one that could induce at least some fun
is just too far away (assuming walking speeds to get there with my toy boat)
The lack of noteworthy lakes and such did the rest for me to never have cared enough about boats...
I've seen one I'd liked (think a two seater kart with a huuuge[as in loud and quick] outboard) small enough to put on a bike trailer almost.. can't even recall the name of it
(had 'kart' in it waterkart, seakart, marinekart or something... but that also might have been a decal the owner put on because of it's small size *shrugs*)
Was too quick to get a second chance to read
That was the first to spark my interest really.

Anyways..
No experience with wetware enginery to give you any solid advise I'm afraid.
So sciencing the shirt off Rusty's chest is all I have in my "what would 'sid do" - drawer

'sid