Stainless fillet question

[Applesauce]

This is kinda OT… The boiler on my Breville DB is basically cracked - it has grown just slightly “porous” near a roll in the metal, and it leaks. Possibly the stupidest failure I’ve ever seen in an espresso machine, compounded by the fact that a) I love this machine and b) Breville doesn’t sell spare parts.

I’ve concluded the thing to do is to lay a fat fillet right over the affected section. It’s too thin and weirdly shaped to weld effectively (and I can’t weld). But it’s thicker than a bike tube, so I think laying a fillet on it shouldn’t be too hard.

Can anyone recommend a product to use? (Or alternative approach?) I need something that doesn’t require more heat than propane (or MAPP) can provide, and which doesn’t contain lead, nickel, cadmium, etc. And the machine is such a nightmare to dissemble and reassemble that I need it to work the first time, even with my minimal skills… 😜

[Andrew R Stewart]

I wonder if an epoxy patch would work and avoid the need to braze. I don't do coffee and don't know how hot or how much pressure is at play here.

I next think of the silver fillers available, including some that the food industry use for their SS devices. IIRC BAg-5 at 45% silver is an example. Unsure as to its liking being filleted, I do know that 56% silver can get internal cracks in attempted fillets due to cooling contraction stresses that other fillers don't have.

I assume that the boiler's insides are able to be flushed with hot water before using for human consumption, you'd really want to dissolve away any flux.

I strongly suggest practicing on the same alloy if at all possible with the filler(s) of choice. SS reacts differently to torch heat then steel does and you say you have one shot... Andy

[Mark Kelly]

BDBs are notoriously unreliable with no available spare parts so dead ones are very easy to find: check the "Pay it Forward" section of any coffee forum.

The common faults are things like O rings leaking and triacs failing so it shouldn't be hard to find one with an intact boiler.

No, epoxy won't work. If you want to destroy an epoxy bond you expose it to cyclical high temperature and moisture.

[steve garro]

This is kinda OT… The boiler on my Breville DB is basically cracked - it has grown just slightly “porous” near a roll in the metal, and it leaks. Possibly the stupidest failure I’ve ever seen in an espresso machine, compounded by the fact that a) I love this machine and b) Breville doesn’t sell spare parts.

I’ve concluded the thing to do is to lay a fat fillet right over the affected section. It’s too thin and weirdly shaped to weld effectively (and I can’t weld). But it’s thicker than a bike tube, so I think laying a fillet on it shouldn’t be too hard.

Can anyone recommend a product to use? (Or alternative approach?) I need something that doesn’t require more heat than propane (or MAPP) can provide, and which doesn’t contain lead, nickel, cadmium, etc. And the machine is such a nightmare to dissemble and reassemble that I need it to work the first time, even with my minimal skills… ��

Yeah, I know what you need to do.
Use 50N, it's both excellent for stainless and it's used for food grade items - I fixed my slightly different coffee maker last week in a few minutes - it builds a fillet just fine, I use it for stainless dropouts with a lot of fill for a large plug in the stay so it's a little more stick around and less flow away if that makes sense.

This alloy:

https://www.gasflux.com/wp-content/u...VER-BAg-24.pdf

I'd be glad to help but you are a little far away and over a border

- Garro.

IMG_4004.jpg

[Moke]

Leave it to the Garro to figure out all things fillet and fix the coffee machine. Tip o da hat to you Steevo, I am impressed.

[Applesauce]

Yeah, I know what you need to do.
Use 50N, it's both excellent for stainless and it's used for food grade items

Thanks Steve! That is exactly the kind of advice I was looking for. Can I use a Harris “50N” product? Are alloys standardized? It doesn’t look like I can get the Gasflux in Canada. (Although I’ll be in Denver this week…maybe I’ll look there.)

What would you use for flux? I can’t reliably clean the inside of the boiler, as the ports are too small. I can fill and soak it obviously.

[Andrew R Stewart]

Where in Canada are you? I'm about an hour+ from the boarder at Buffalo/Peace Bridge. I've helped out others by meeting them there and handing off the stuff.

https://www.bikefabsupply.com/flux sells the Gasflux brand and they claim to ship to Canada. Andy

[steve garro]

Thanks Steve! That is exactly the kind of advice I was looking for. Can I use a Harris “50N” product? Are alloys standardized? It doesn’t look like I can get the Gasflux in Canada. (Although I’ll be in Denver this week…maybe I’ll look there.)

What would you use for flux? I can’t reliably clean the inside of the boiler, as the ports are too small. I can fill and soak it obviously.

Here's the makeup:


Chemical Composition of Ag-50 (BAg-24) Cu Ag Zinc Nickel Other
20% 50% 28% 2% .15%


But I bet it's right in line as the same alloy, one troy ounce should be sufficient, you can show me the issue I may have a better idea but one TO is a bunch - you also need flux, type "U" is what you want, a pound is a ton but with your one TO of alloy you will be prepared for future issues, maybe get it shipped to you destination in CO?

https://www.gasflux.com/catalog/past...-u-paste-flux/

Yeah, I'd take some boiling water and soak it overnight, it knocks of the flux in <10min but just to be sure, then maybe run a dummy run to flush it out.
Glad to help !

"Soy Manoso"

- Garro.

[Applesauce]

Yeah, I’ll just have it shipped to my destination in Denver. Should arrive pretty quick from Phoenix!

I started a plumbing apprenticeship a couple months ago, and today I have a whole day of soldering shower valves. Good chance to brush up on my torch work!

[steve garro]

Yeah, I’ll just have it shipped to my destination in Denver. Should arrive pretty quick from Phoenix!

I started a plumbing apprenticeship a couple months ago, and today I have a whole day of soldering shower valves. Good chance to brush up on my torch work!

Totally !

Heat the thick part !

Let us know how it goes

- Garro.

[j44ke]

My experience with espresso machine boilers is that the corrosion outside comes from inside, so any repair you do outside is usually building on a shaky foundation. I've replaced boilers in Saeco and Delonghi super-automatics, and it isn't hard but it is more successful - especially when the boiler is some sort of bi-metal contraption of stainless and aluminum. I can't imagine the Breville line to be that much more complex than a super-automatic.

https://www.ereplacementparts.com/br...52_116055.html

[shand]

I'll echo j44ke here. I've done a lot of that sort of thing and I'll also wager the corrosion is way worse on the inside. I'm not saying don't try it but be prepared for it to fail. They're good machines generally but not really user serviceable for the average person so they do appear on ebay etc fairly often over here as 'broken'. I'd attempt to track down a replacement boiler before doing a repair if I were you.

[Applesauce]

I understand the impulse to say, “those machines suck, just replace the boiler”, etc. The reality is, this machine is eight years old and has had fewer issues than any La Marzocco, Rocket, Gaggia, or La Pavoni I’ve ever owned or serviced. The pumps and solenoids are common items. The o-rings and hoses are all standard. I don’t bother with the stock descale cycle because it’s a pain in the arse, but so far I haven’t seen any issues with the electronics. So to the haters, maybe get some hands-on time before you write off my machine. I’ve worked on a $30k La Marzocco, an $10k Rocket, and lord knows I’ve worked on this Breville…I’ve seen lotsa sides.

I would’ve ordered a new boiler and replaced it last time I had it apart if that were an option. It’s not. I don’t know why this boiler has failed like this, but it’s not because of corrosion. This machine is spotless, well cared for, and our tap water is second-to-none. It failed because of shoddy manufacturing, and I think attempting to repair the boiler I have is a better option than replacing it with someone else’s unknown quantity. Worst case scenario, I have a boiler that leaks same as it does now! Plus I kinda appreciate the challenge…

I’m not Steve Garro or Eric Baar with a torch, but I also wasn’t born yesterday. It has been twenty years since I soldered a bike frame, and I’ve never built a fillet on stainless. But I’m about to learn!

[bigbill]

Coming in from left field here. If the repair is out of sight, have you considered JB WaterWeld epoxy? It can handle high pressure and up to 250F. I carry it in the travel trailer in case I need to fix something with the fresh water system. I got it to stick on a small crack in my water tank while it was still actively leaking and a year later, it's all good. You can fill the crack and sand it down as well.
https://www.jbweld.com/product/waterweld-epoxy-putty

[Matthias]

Interesting discussion! Interesting because I used to believe you can not braze on stainless using regular flux and you needed 'black' flux with an addition of metallic boron to get brass to wet. Recently I was in a pinch and didn't have the parts I wanted to braze made out of low alloy steel on hand.
I used my trusty choice of flux (FH21, it's an industry standard, AFAIK a mixture of borax and boric acid) and some brazing rod (40/60). The brass behaved differently but it worked, made a strong bond and the flux' action is well evident on the finished parts.
I want to add that 'stainless steel' is a really poor way to classify steel for any other purpose than it's general corrosive properties. This means my stainless steel used in this example is completely different from the stainless steel in a coffee machine and may or may not behave radically different when brazed with standard flux and brass.
Either way I believe the method could work and meet all the requirements outlined in the original post: Only copper and zinc, no lead, cadmium etc. The flux dissolves easily in water and can be removed through repeated flushing. The temperature needed for brass can be reached with propane in ambient air and I even believe it to be realistic, considering the thickness of the material in question and the size of rod one would want to use. Lastly it builds fillets perfectly well. You can bridge anything with it.

Matthias