Getting to the bottom of things or clean until there is nothing left to clean

So with a new (old) espresso machine comes a lot of responsibility cleaning.  Unfortunately one finds that just because someone says they cleaned a machine or that they say it has a problem with a pump does NOT mean that is true.  I’ve found that just because I take everything apart and soak it in cleaners and sanitizers and sometimes even hit it with a steam cleaner or some other method does not mean that someone else did.

After finding that something was shorting out I googled for things that cause this and the most likely scenario was that the heater was shorting out.  If you google “repair espresso heater element” or something similar you are likely to find one of two articles posted at Orphan Espresso about how to repair a heater element that has been damaged by water leaks.  In those articles they tell you to disconnect the power leads and get in between the metal of the boiler and the various parts of the heater element.  You will find a center metal element wrapped in various materials such as ceramic, other metal bits, and some sorts of resin/epoxy like material or other insulating things.  What happens is over the years the material cracks and breaks down and absorbs water like a sponge into all the nooks and other broken bits.

To repair this you have to test the metal boiler to element to prove there is a short with a resistance check using a multi-meter.  If a reading between the metal body and the heater element connection shows continuity then you have a short.  If you look around the wire and probe it with a fine metal pick you will probably see the material start to crumble and flake out.  You will need to dig out all of the material that will come free scraping and digging until it seems solid.  You will STILL have a short after this.  Depending on how adventurous you want to be you have two possible options.  If you have a heat gun you can start off there and possibly get lucky.

Previously I had been remodeling a house and used a heat gun to help speed up drying certain paint touch ups and for removing paint from woodwork.  I had picked up a heat gun from Home Depot to do this and had used this one linked from Amazon below:


Wagner Digital Heat Gun HT3500

You don’t really want to set it more than about 500 degrees and only want to hold it a few inches away waving it around somewhat quickly not lingering directly on it for more than a couple seconds. After a few minutes check it again with the meter. After about 10 minutes of warming it up repeatedly it should dry out and show no connectivity.  If it continues to show connectivity keep heating it up some more but if it never gets any better you might need to replace the heater.  The article on Orphan suggests removing the heater from the boiler and baking it,.  Depending on the age and “standardness” of your boiler you might not want to take it apart due to possibly having problems finding new gaskets.

In my case this is a non-standard machine.  If the gasket was damaged when taking it apart I’d have more difficulty finding a replacement.  I may still need to do this but for now the boiler wasn’t leaking around that area so I didn’t want to risk it.  Obviously you will need to try to drain the boiler and any water tanks before tipping your machine over to get to the heater parts if they are not available on the top or sides.

When I flipped the machine over I had a plate.

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After removing the bolts and taking off the plate I saw evidence of rust on the contacts.  Obviously water had come from somewhere at some point and got into the heater parts and clearly rusted the connectors.

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I went to an automotive parts store and purchased a clear liquid that removes rust.  You want something that eats the rust off and converts it.  Not something that converts the rust where it is and builds new layers.  Usually the kind that removes it and converts is somewhat clear or yellowish.  The one I used was “pH neutral” and thus not an acid.  You should probably try to find something like that.  The ones that are milky white or bluish are binders that convert the rust into a crusty black later bonded to the surface should not be used because it might cause issues with the electricity and the connector.

To rebuild the insulator around the heater I had to use a non-conductive high temperature epoxy.  I also used an insulator paint to cover the replaced epoxy.  When it was done it looked like this (I just painted over the end  more than was probably necessary but it’s not exactly easy to paint the insulator in sometimes).

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To seal it I used a tube of epoxy putty from Amazon:

Rectorseal EP-200

They have a larger tube that is the same material in case you use epoxy more regularly than I do. The 200 number on the end has to do with the size. an EP-400 is the bigger version of the EP-200 (2 ounce vs 4 ounce). This epoxy is NSF certified for food/drinking water contact and is safe for 500 degree Fahrenheit contact. You have to let the epoxy cure for at least an hour before painting it. I tested the multimeter readings after installing the epoxy. It shows a short until the epoxy is cured. The epoxy hardens in just under 15 minutes. I used some tools for working with moulding clay for making decorative beads and figures to push the epoxy down into the gap and smooth it off.

I picked up the tools from Michael’s (a craft supply chain) and paid way more (4-6 times) for it than the Amazon price:

11 piece Clay Tool Set

After it curing for an hour I then used an insulator varnish that I also picked up from Amazon:

MG Chemicals 4228 Red GLPT Insulating Varnish, 55 ml Bottle

The more commonly recommended insulator paint is something called Glyptal. Finding that might be possibly for you but I was not able to find it or anything like it nearby. I’m pretty sure the GLPT in the description is in reference to Glpytal. It is a strong insulator once dried and seals out moisture and is able to withstand a bit over 300 degrees Fahrenheit worth of heat. Glyptal has the same basic properties.

After letting it dry I found the same test results with the multimeter showing the short repaired. I used the heat gun to hurry up the drying so I could test the multimeter reading. I let the entire thing sit 24 hours before turning the heater on for testing.

Prior to working on the heater I tried cleaning the machine.  I had to remove the dispersion screen/bolt but the first screw driver I used was too small.  I found that the only screwdriver that worked well was a HUGE 5/8 inch wide flat screw driver.

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Once I did that with the correct screwdriver I found that the item did not seem like it had ever been cleaned because it never looked like it had been removed before my attempt.  It looked like this inside where the water comes in against the back side of the screen.

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Looking at the underside I saw evidence that the 8 outlets for the dispersion bolt were blocked.  Only 3 clearly had a strong water path etched in the gunk left in the machine due to it not being cleaned.

 

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After a good cleaning the dispersion screen/bolt looked like this:

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The area behind the dispersion screen looked like this:

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The following day I started up the machine and the heater did stay on and the whole system cycled through heating, steaming, and dispensing.  Pressure looked a little low until I ran some TSP through the system diluted in water.  After a few minutes of flushing the cleaner into the tank suddenly huge blobs of espresso grinds started squirting out of the machine and all of the water was dark dark brown.  Several gallons of water through the system later it came out clear-ish and I moved on to other cleaning solutions.  Following the brown water and espresso grind mixtures I found the pressure in the machine drastically improved.  I would say it was the difference of a trickle vs it gushing out once the brown had gone away.

As a result of the above I spent $362 for the machine on eBay.  I bought a $3.81 tube of epoxy putty and $10.33 for the insulator paint.  The rest of the items were pretty much optional and technically I only used about $0.10 worth of any of them.  So skipping the tools since I will likely still use them for other things or already had them – I spent $376.14 for this espresso machine.  Add to that about $15 worth of gas to drive to and from where I picked up the machine.

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