I'm working on a friend of a friend's boat , who self winterized last year .
well he didn't do so well and blew out the 2 front plugs on a volvo 350. Ive got the engine supported and removed the mount on one side, so my question is do I just tap in the new plug after cleaning the rust , or do you use a sealer of some sort.

i use leak lock,without some type of sealer it could leak.

Also make sure you use brass plugs. Hopefully noting cracked.

everything seems ok , and yes brass plugs for sure. I'm no engine guy so I just wanted to be sure as these were a pia to get to.
​​​​​​​mike , is leak lock readily available otc. Thanks

Just about every kind of sealer has been used and successful just make sure you clean the core extremely well. Wire wheel and emery cloth or both. No visible rust or pitting before install. I've used permatex super 300, Indian head, and regular rtv sealant. Some use nothing however I'm not one of them.

He he got lucky cause blocks with popped plugs can and likely still crack elsewhere.

Pull the intake and check the valley under the pushrods. If water level dropped before freezing, may be ok. If it was full, it'll be cracked there.

if you have a high oil level possible already crack. I would drain motor oil if all possible from the oil pan. Water ends up in the bottom of the oil pan as it will fall out from the motor oil over time

For marine service and repairs of seals, oil seals, plugs, bushings and so forth we use over many years the retaining compounds from Loctite.

Retaining Compound | LOCTITEŽ - Henkel Adhesives North America

for anyone that can use this - I have it in book form as well.

http://na.henkel-adhesives.com/us/co...Brochure_F.pdf

Also a bit of seepage around a freeze plug in a raw water boat won't be the end of the world. You have the world's largest cooling system.

My .02$ worth, long and short. "Before" I bought my boat the STB motor froze at some point; I was making water the first 3 times out this year and couldnt find the leak. Luckly I ended up pulling the motor to do a coupler repair and discovered the cracks on the outboard side of the block in very close proximity of the large 1-5/8 freeze plug. When I removed the plug it was a colossal *****; once out I could smell and see the unmistakeable remnents of Loctite Red.. I'd say whatever you use, dont use that lol...