What type of coolant to use?

[DollarBoat]

I am trying to figure out what type of coolant I have in order to top up the overflow container which is empty now. The boat is a ‘98 Sea Ray with a 5.0 Merc and an aftermarket closed cooling system added. The colour of the coolant is neon yellow with slight green tint.

 

[jbcurt00]

Marine or RV, both are environmentally safe.
Never automotive which isn't environmentally safe.

I've never seen typical green AF that's marine or RV. They are a different color to positively ID them as RV/Marine.

If you don't know it's Marine or RV, drain & refill

I suspect someone used the wrong stuff if it's green

 

[nola mike]

Marine or RV, both are environmentally safe.
Never automotive which isn't environmentally safe.

?
I haven't heard of RV coolant being used in a closed cooling system. That stuff is for winterizing, not heat exchange AFAIK.

 

[dubs283]

?
I haven't heard of RV coolant being used in a closed cooling system. That stuff is for winterizing..... AFAIK.

You'd be surprised what engine manufacturers are using for anti freeze today. I know for a fact Ilmore uses poly for running af these days. Is strange but I figure routine maintenance with a close eye gives excellent results, ymmv

 

[Scott Danforth]

If it's green, use green if it's orange, use orange

Never mix them