I finally got that old pressure valve on the boiler at the old mill to seal right

It took three tries with different gasket materials before the brass one from the shop in Norfolk held at 150 psi. What's your go-to method for sealing up those old, pitted surfaces underwater?

3 comments

3 Comments

the_sandra1mo ago

Read an old marine engineering manual that swore by a two-part epoxy putty for temporary underwater seals on pitted metal. You mold it around the valve like clay before it sets. It's messy but can get you through until a real fix. The trick is to rough up the surface with coarse sandpaper first, even underwater, so it grabs better. I'd still replace the whole valve at the next dry dock, but it beats a total failure on site.

matthewgonzalez1mo ago

Heard a story from a guy who used to work on tugboats about packing the worst pits with grease and then wrapping the whole flange with that self-fusing silicone tape. It's not a forever fix, but he said it could hold for a few months if you stretch it tight enough. The grease keeps the water out of the deep spots while the tape does the squeezing. Always seemed like a clever field repair to me for when you're really in a bind.

the_daniel1d ago

You ever try that tape yourself? I had a buddy who worked on a dredge boat years back and he swore by that same grease and tape trick. He told me one time they had a flange on a cooling line that was pitting so bad you could see daylight through it. They packed it with bearing grease, wrapped it with that self-fusing tape, and he said that fix actually held for a good six months until they could haul out. Matthewgonzalez, your buddy's story is spot on, that stuff is like duct tape for the ocean. Always amazed me what guys will come up with when the boss says "just get it running til Friday.