Sealant for Espresso Machine Fitting?

Would something here work? It sounds like a bolt going into an engine block.

It is kind of like a fine thread bolt, except it's a nipple with water/steam going through it and there is no head, just a lock nut.

I have some permatex non-hardening in the garage and was even thinking of using it, but it's not food safe. I don't see that they have anything food safe either. I don't think it's really that big a deal, any contact between whatever is there and the water would be very minimal. But food safe would be better. I think I have it solved, thanks to good old Ebay.

That listing doesn't say it's food safe, but you can see it on the label and other sellers have it listed as food safe. Food safe and high temp, hope it works. They must have used something other than silicone when it was made 25 years ago because you usually have remnants of silicone left and you know it was there. Seems like there was something on there, but more solid, like threadlocker kind of stuff maybe. For $6, this is worth a try. Next problem, I broke a part in the portafilter, have to get that from Bulgaria, $20. Sigh.....

Why not treat it like any other straight thread fitting and put a gasket under the lock nut. That is what Yamaha does on their outboards. An O ring that is tight on the threads should work.

Suggest you contact Saeco customer service for their assistance. If you can't find contact information for them, I'd contact the retailer where you purchased the machine. If that doesn't help, look for a factory authorized repair facility for Saeco espresso machines (even if your machine is out of warranty they may still be able to help).

I don't see how a gasket or o-ring under a lock nut keeps water from following the threads, right on through the nut. I've never seen a fitting that worked that way. Gaskets work where you just have two flat surfaces meeting. It would work with a *bolt*, because it's a bolt, not a nut and the bolt doesn't have threads coming out the head to leak. The washer will seal the perimeter, but do not the path through the threads.

Hydraulic fittings on farm equipment sometimes use washers with O rings or flat rubber washers at least on the low pressure return lines. The washers are made with the O rings/rubber washers attached. I think the washers are convex and collapse as one tightens them so the O/washer collapses against the fitting as things are tightened. This might be a good illustration.

If the O ring is tight on the threaded part it should stop the flow.

Has it always leaked? If not, what changed? If so, why didn't you get it fixed or take it back when it was new?

Assuming you are not adjusting this, you could always epoxy the nut to the threaded part and use a gasket/O ring once you find the right spot.

That shows exactly what I'm talking about and why an o-ring won't work with a nut instead of a bolt. In your photo the o-ring seals between the two flat surfaces and there is no path through the *threads*.

I can't be tight, can't work, because the threads are not a flat, smooth surface, they are a spiral with peaks and valleys. The o-ring will be on the peaks, the fluid will follow the spiral valleys. It works on Dean's example because it's a bolt and there is no path through the threads beyond the o-ring.

Like I first posted, I had to replace the steam valve because that was leaking, not the nipple connection.

Appears to me the 6500 sealant I found, that's food safe is the best option.

On Sun, 21 Mar 2021 23:12:31 -0400, snipped-for-privacy@aol.com posted for all of us to digest...

That is what I would suggest.

Trader: Megalock might work for the temp but not the pressure. That product you linked to looks like high temp silicone but I don't know about the pressure.

Is there any of the espresso maker USA contact or maybe something on their website?

How was the nipple sealed before?

Like I said, IDK. When I went to take the nut off the old nipple, it would not come off easy. There was a little bit of something on the threads. Not sure if it was some mineral deposits, corrosion, or sealant. But given that something had to be there to keep it from leaking, I'm betting it was sealant. I wired brushed it a bit and put some PB Blaster on it and it came right off. The parts diagram does not show any part going between the nipple nut and boiler fitting.

Whatever was there, I don't think it was RTV though, because that leaves traces that are silicone like material, bits that are rubbery, etc. Whatever was there must have been more like threadlocker, but I have confidence that RTV will work. We'll see.

Update. I got the silicone sealant and it worked, no more leak at the fitting and with the new steam valve, no more dripping from the steam wand. If anyone needs similar, it's Silco RTV 6500. Good to 500F and food safe. It cost ~$6 on Ebay.

On Sat, 10 Apr 2021 06:30:15 -0700 (PDT), trader_4 posted for all of us to digest...

Thanks, good to hear of a resolution.

Yeah, that's all nice.

Me? I'd pop for a $15 Mr. Coffee at Walmart ;-)

On Sat, 10 Apr 2021 19:16:34 -0400, Wade Garrett posted for all of us to digest...

Ya like what ya like so both of you can have your Covfefe the way YOU like it ;-)