Vibiemme Domobar Super Black
Rust Investigation Findings and Comments
I was cleaning my black Vibiemme Domobar Super in December of 2009. It had been in service for just under 2½ years at the time. I had removed the drip tray cover and drip tray and was using a towel to wipe out the area of the base under the drip tray and along the stainless face of the machine that rests behind the drip tray. As I wiped I heard a metallic rattle. I lifted to towel out of the way to find this:
Moisture had gotten under the support bracket and over time this level of rust took place. It took place without my knowledge because the rest of the machine appears virtually rust-free, and the rusted areas are totally hidden from view by the bracket.
At that point I posted an article on two of my favorite coffee forums as well as detailed information here on my site asking for folks with VBM Black machines to check this area and report back to me as to whether they found rust or not. I had three other users report that they had found rust (photos of one machine would seem to indicate that it was not well cared for). This certainly does not indicate any pattern of such a problem, and with the sales of all Black VBM machines, four data points are not enough to cause alarm at this time.
But the cause of the problem remains; it is twofold: The first is that it is easy for moisture to get under the drip tray if the user is not very careful and diligent. Many users will clear the steam wand into the drip tray. This is a common procedure for the home user, but the design of the drip tray on the VBM Domobar machines can allow water to get pushed back, over the back wall of the drip tray. From here it dribbles down the face of the machine, between the face and the tray, and onto the frame under the tray. The amount of water that ends up under the tray is proportionate to the amount of water in the tray, the force of the steam, where the steam is aimed, and for how long the wand is cleared. I experimented and found that even if the tray is completely dry and empty, water can still end up under the drip tray. The steam can condense on the stainless steel face and water droplets still form and dribble down. Normally, the amount of water is negligible, but depending on some of the factors mentioned above, and the amount of care and cleaning the machine receives, it has the potential to cause rust to form.
The newest models of the VBM Domobar machines feature a lip on the face of the machine, just above the drip tray, designed to redirect water from backflushing and splashing on the face of the machine into the drip tray instead of behind it. This solves part of the problem, but does not address the problem of water that is already in the drip tray from splashing over the back side (as in the case of pulling out a very full tray or clearing the steam wand as mentioned above. A simple solution in design could go a long way towards solving this:
Artist's rendition of a lip at the rear of the tray would keep water or steam for being pushed over the back wall of the drip tray. The depth of the lip would be slightly less than that of the solid area of the cup rest.
The second problem which contributes to the rust problem is caused during the manufacturing process. Whether you call it a defect, design flaw, or a manufacturing oversight, the problem remains that the area concealed by the support brackets and between each bracket and the main framework is not properly powder coated. The underside of the bracket where it sits on the frame cannot be powder coated because the coating goes on after the bracket is welded to the frame. Even if it was first coated, the spot welding would burn it off. The void formed under the raised portion of the bracket (the "tunnel" area) cannot (or at least has not in my case) easily receive powder coating.
The user needs to address this situation. Prevention is a start. Never allow water to enter or gather under the drip tray- easier said than done. The most difficult (actually, nearly impossible) area to keep dry is inside that "tunnel", between the support bracket and the side wall of the frame. The edge of the bracket where it meets the floor of the frame is not properly sealed, and so water can get underneath the bracket, and once that happens there is no effective way of removing it. This is exacerbated if descaling solution or backflush detergent gets in there. Whatever the liquid, it will seep under the bracket and begin to oxidize the exposed steel. Even if you have no rust, I suggest an application of a quality rust preventative product. Even spraying some WD-40 or similar product and tipping the machine back and forth to get it to flow under the bracket once every month or two will go a long way towards preventing rust in that area.
But what if rust has already begun to form? If you do not want to rip the brackets out and fabricate a solution as I did, I suggest getting a rust converting product. I have used them on heavily rusted metal on an old car, and it really works! CRC Rust Converter #18418 is one. After treatment you will need to also pour some paint in there to protect the converted metal. This will be a messy job that should be done outdoors on a disposable drop cloth. As mentioned above, prevention is the best course of action.
The design in this area could certainly be improved. Two solid rails, spaced away from the sides of the frame, brazed or welded in a way that seals them completely so water could not enter and still allowing user access might be one factory solution. Two plastic rails that are attached with screws after powder coating would also work just fine. Another could be like the one I actually created:
This plastic support drops in over the nuts that hold the front feet.
If you would like a printable, full-size pattern of the support I made, RIGHT click on the appropriate link below and choose to save it to your computer :
Be sure to print the file with the print option of NO SCALING, then compare the printed scale to an actual ruler to be sure that the size is correct.