Results 1 to 7 of 7
Like Tree4Likes
  • 1 Post By Jackster
  • 1 Post By Jackster
  • 1 Post By Lyrebird
  • 1 Post By Lyrebird

Thread: VBM Domobar Boiler - worth attempting restore?

  1. #1
    Senior Member solace's Avatar
    Join Date
    Oct 2016
    Location
    Adelaide, SA
    Posts
    178

    VBM Domobar Boiler - worth attempting restore?

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    Hi all,

    So I picked up a VBM Domobar Super HX today for a possible restoration project. The boiler is intact however has signs of leaks plus one of the valve connections has been ripped off.

    Is the boiler worth attempting a restoration? I assume I can get a boiler maker or similar to weld the valve connection back on?

    Previous owner said they took it for a service as was leaking steam, apparently the person performing the service ripped off the connection from the boiler then promptly told the previous owner the boiler needs replacing.

    Pics for reference:

    12FB03E6-A49A-4DC6-9F5E-55C6065A89D2.jpg50092900-3093-4BED-9A0E-886589BE49E8.jpgF728627A-066A-4F8A-945D-C89D3AECE02D.jpg1649F886-0A48-4336-BA01-74706B561E25.jpg

  2. #2
    Senior Member Jackster's Avatar
    Join Date
    Nov 2017
    Location
    Maddington, Perth. Wa
    Posts
    844
    It looks like it was a screw in fitting that has snapped. It needs drilling out and the threads restoring.

    How much is a new boiler? You will burn up a heap of hours cleaning, repairing and pressure testing the old boiler. There is a couple of hours work just in removing and replacing the boiler.
    Happy travels!
    solace likes this.

  3. #3
    Senior Member solace's Avatar
    Join Date
    Oct 2016
    Location
    Adelaide, SA
    Posts
    178
    Ah, yes, screw in fitting is the term I was searching for there - thanks!

    From what I can tell a new boiler is $600ish. I’m not too fussed about time and effort to restore the boiler (if it can be restored), I have a perfectly functional Gaggia Classic to keep me caffeinated whilst I do the dirty work with this VBM.

    If a new boiler is the only way then so be it, I’ve spent $20 on buying this machine.

    Will read up about steps involved with pressure testing boilers, this is my first E61 restoration project and my second project altogether (first was rebuilding my Gaggia Classic).

  4. #4
    Senior Member Jackster's Avatar
    Join Date
    Nov 2017
    Location
    Maddington, Perth. Wa
    Posts
    844
    Well pull the boiler out, descaling it, get that fitting out and the threads cleaned. Then get some fittings to block the holes, fill it with water and pressurise to 30psi. (I brazed a car Schrader valve into a fitting, and pump air into boiler with a gauged bike pump).

    Then see if it holds the water inside.
    solace likes this.

  5. #5
    Senior Member Lyrebird's Avatar
    Join Date
    Jun 2018
    Posts
    424
    There are two possible routes to fix that fitting.

    #1 is to simply remove the boiler, clean off the teflon tape that shouldn't have been used in the first place and run a BSP* tap though the fitting. If you see brass all the way into the fitting after this process you are good to go. If you were in Melbourne I'd lend you the tap but since you're in SA you'll have to source one yourself, they're not terribly expensive but you need to make sure you order exactly the tap you need.

    If this fails go to #2 which is to drill / ream out the fitting and braze in a new one, they are available from your local Reece plumbing outlet (just go to the trade side not the consumer bunny side). Brazing copper and brass fittings is a doddle, it can be learnt by the average mechanically competent human in an hour or so. Ideally the hole should be reamed to 0.2mm larger than the OD of the fitting, this will result in optimal strength of the brazed joint due to plastic restraint.

    You can pressure test the boiler by attaching it to your garden hose. If it doesn't burst you are good to go.

    It is usually deprecated to pressure test a vessel with a compressible medium like air. An incompressible medium like water is much safer due to the difference in energy strorage in the media.






    * European fittings use the ISO standard but don't be fooled, this is just BSP in disguise.
    Last edited by Lyrebird; 28th January 2019 at 09:31 PM.
    solace likes this.

  6. #6
    Senior Member solace's Avatar
    Join Date
    Oct 2016
    Location
    Adelaide, SA
    Posts
    178
    Thanks Lyrebird. I have never brazed anything before (okay, maybe some beef) but have soldered many an electrical join, I assume I need an oxy or propane torch?

    With regards to pressure testing the boiler, should there be any pin-hole leaks could I seek to repair these (probably via a steam boiler maker or radiator repairer) or is that enough potential instability to cause concern for the boiler long term? I ask as there is one spot on the boiler that has (what I think are) copper deposits (blue), the spot is small and not close to any other fitting that I could think would be leaking.

  7. #7
    Senior Member Lyrebird's Avatar
    Join Date
    Jun 2018
    Posts
    424
    An oxy / propane setup from the big green shed should do fine. I have an oxy / acetylene rig which I use for stainless steel and bigger copper jobs but I use a plain propane torch (an old primus) for small copper jobs and it works fine.

    I can't answer your questions regarding the flaws without seeing them in person.

    If it doesn't pass the pressure test first up, get it looked at by someone who knows what they are doing. Not worth hurting yourself to save $600.
    Last edited by Lyrebird; 29th January 2019 at 10:07 AM.
    solace likes this.



Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •