Wet Liner - Best Paint???

[Wotname]

What is best practice regarding painting a wet liner before fitting to the block / crankcase?

The engine in question is a raw water cooled single cylinder Yanmar (YSE-8). One service manual requires the liner to be painted before installation with an "anticorrosive" paint. Another manual requires the sealing lip (at the head end) to be painted with "white" paint during insertion of the liner. Neither are more specific regrading detailed paint type.

It would seem to me that any paint suitable for underwater use on a steel hull should be suitable for the liner and perhaps the paint is not that important except for use on the top sealing lip. The rest of the cast iron crankcase has minimal paint protection in the water galleries and relies on the anode for corrosion protection. FWIW, water temperature is around 50C (~120F).

Thoughts???

[Captsteve53]

My Yanmar rebuild book for the engine says to "apply sealing paint or grease" to the outside lower part of the sleeve where the packing (o-rings) seal the sleeve against the block.,

This is always about the interference fit and or damage to the O Rings or landing area's metal to metal and sealing, Any engine where I have replaced wet liners I use Silicon O Ring lube for the O ring area's and other lower or general metal area's coat with DURALAC (mixed with a little Silicon grease) as it will seal and provide long term corrosion protection,

https://www.fisheriessupply.com/sadd...nting-compound

Another tip is place the liner in your freezer the night before, then add the O Rings/Silicon grease/Duralac and insert ASAP

Once you have Duralac there's thousands of vessel applications/every boat owner should own a tube on there boat

Cheers Steve

[Wotname]

Originally Posted by Captsteve53

My Yanmar rebuild book for the engine says to "apply sealing paint or grease" to the outside lower part of the sleeve where the packing (o-rings) seal the sleeve against the block.,

This is always about the interference fit and or damage to the O Rings or landing area's metal to metal and sealing, Any engine where I have replaced wet liners I use Silicon O Ring lube for the O ring area's and other lower or general metal area's coat with DURALAC (mixed with a little Silicon grease) as it will seal and provide long term corrosion protection,

https://www.fisheriessupply.com/sadd...nting-compound

Another tip is place the liner in your freezer the night before, then add the O Rings/Silicon grease/Duralac and insert ASAP

Once you have Duralac there's thousands of vessel applications/every boat owner should own a tube on there boat

Cheers Steve

Thanks Steve.

I have the Duralac. I plan to use the freezer and also to have the block comfortably warm (say 40+C).

What of the top lip fit, paint or more Duralac?

[Captsteve53]

I would go with the Duralac as it far out weighs " the ambiguous paint" in benefits such as sealing and corrosive actions, again i usually dilute a little if the Duralac is getting old and a bit stiff, again with a very small addition of silicon grease or oil , if the tube is new no worries

Cheers Steve

[Wotname]

^^ makes sense

[model 10]

Red Rust-Oleum primer is considered suitable for the interior of an engine.