1. Time for some upgrades in server hardware and software to enhance security and take AK to the next level. Please contribute what you can to sales@audiokarma.org at PayPal.com - Thanks from the AK Team
    Dismiss Notice

Black on glass experiments?

Discussion in 'McIntosh Audio' started by janikphoto, Dec 19, 2013.

  1. janikphoto

    janikphoto Lunatic Member

    Messages:
    10,539
    Has anyone ever experimented with ways to patch the flaking black on the McIntosh glass? It seems like there'd be a way to paint the holes to look close for those of us who want to salvage the original.
     

     

    Please register to disable this ad.

  2. damacman

    damacman Blown and Injected Subscriber

    Messages:
    8,818
    Location:
    Gilbert, AZ
    It can certainly be painted. I used to mix Testors Gloss Black and some other brand Jet Black to get the right black. Depending on how much sun the face of your unit saw depends on just how "black" the paint needs to be to blend perfectly. Use a NEW razor blade to cut out the affected area and then dab the paint onto the glass with a small brush allowing it to wick under the perimeter of the now paint free area. This can be done for small (less than 1/4") areas with excellent results. I actually built a face plate light box so that I can lay the glass letter side down on the box and turn on two 40 Watt bulbs. This exposes all problem areas. You can NOT fix areas of bubbling that are near the lettering - don't even try or you will destroy the face plate. I have on several occasions repaired the offending area around the headphone jack, but first the old (shrunk) epoxy must be chipped off and that takes a bit of patience.

    As always, try your hand at a SMALL area first and then move on to other areas as your skills improve.
     
    Cadillac Kid likes this.
  3. jlovda

    jlovda Things I loved from the 60's and 70's Subscriber

    Messages:
    3,479
    Location:
    NE Ohio
    What do you do if the bubble is underneath the clear plastic light diffuser? You can't remove it without destroying the black paint.
     
  4. damacman

    damacman Blown and Injected Subscriber

    Messages:
    8,818
    Location:
    Gilbert, AZ
    That depends on the model. In some cases you actually can remove the diffuser. In other cases you can't as it is held on with double sided tape - pull that and the paint comes along with it.

    I've restored the glass on some units that you just wouldn't of thought could be restored, including a few MC2505s with bubbling around the headphone jack. The trick is to take your time and hone your skills. I always looked at it like this - if I screw it up I can STILL buy a new face plate from McIntosh.
     
  5. janikphoto

    janikphoto Lunatic Member

    Messages:
    10,539
    Good point!
     
  6. CountD

    CountD Super Member

    Messages:
    1,239
    Terry has always said to use black gloss Rustoleum in a can (not spray) and build up layers (glob it on) once the old bubbles and paint are removed with an exacto knife. Works great for me.
     
    Don Bocadill likes this.

     

    Please register to disable this ad.

  7. dewickt

    dewickt Will fix about Anything

    Messages:
    3,399
    Location:
    Knoxville, TN
    With some patience and a heat gun the diffuser can be removed, just don't heat it too much causing it to warp or melt. This will get about 50% of them off with no damage to the paint, the rest probably will be beyond repair so be prepared to buy new glass. This method can also be used to remove the blue filters in front of the meters, just don't over heat and warp them.

    Merry Christmas - Ho Ho Ho
     
    Don Bocadill likes this.
  8. william13

    william13 That's not me

    Messages:
    983
    Location:
    Florida
    Reviving this old thread
    Regarding a MR78 faceplate: What layers are applied by the manufacturer to the inside of the faceplate? For lack of better word if an area of grey discoloration occurs does one remove the local area or does one cut out a larger window to be painted?
    How does one use xacto knife? Does one cut a square out around the bubble? How does one protect the edges that occur as a result of the cut out? Is a scrapping motion used to clean glass or does one try to enter from edge of glass and lift layers?
     
  9. c_dk

    c_dk Addicted Member

    Messages:
    6,314
    Location:
    West Michigan
    I flick it off, removing all loose black.....ragged edges seem to work out OK.
    According to our rep years ago the green and then gold screened layers are a fish oil based paint.

    A grey discoloration I think indicates lifting paint.
     
  10. william13

    william13 That's not me

    Messages:
    983
    Location:
    Florida
    Thanks: So lets say I have a perfect MR78 glass except the bottom edge of glass where there is no printing almost has a scrimshaw type design that is about 1/3 of an inch high and covers about 70% of the bottom. In this case I would simply scrape the grey off and not worry about creating a straight edge across (ie I would not cut out a large thin rectangle). The I would dab with paint (of which there does not seem to be an agreement on) ie glossy model paint or rustoleum. Is that it?
     
  11. 62caddy

    62caddy Trust but verify Subscriber

    Messages:
    9,592
    Location:
    NEPA
    It is not critical how straight the edges are created by the removal of bubbled paint since you will be painting over it anyway. It will not be seen from the front.

    The important part is to ensure all loose paint is removed first. Secondly, be very careful not to disturb areas containing lettering because that cannot be duplicated. On that note, bubbling underneath any lettering cannot be repaired. Replacement glass is the only remedy in those cases.
     

     

    Please register to disable this ad.

  12. c_dk

    c_dk Addicted Member

    Messages:
    6,314
    Location:
    West Michigan
    The anti rattle foam reacts with he paint causing the lifting you are describing. Once you get the glass out of the frame flick off the loose paint and then apply the rustoleum with a trowel.....flat blade screwdiver works well. Apply liberally or you will be chasing holes and light spots forever.

    All these 40++ year old units will do this eventually.
     
  13. 62caddy

    62caddy Trust but verify Subscriber

    Messages:
    9,592
    Location:
    NEPA
    I don't know if it is so much the foam itself causing the bubbling as the bubbling tends to occur along the bottom rail rather than the top. I think it's due to glass cleaner sprayed directly to the front panel which runs down into the bottom rail which the foam absorbs and wicks into black paint causing it to lift.

    Glass cleaner should be sprayed on the cloth, not on the unit itself.
     
  14. c_dk

    c_dk Addicted Member

    Messages:
    6,314
    Location:
    West Michigan
    It does it at the top rail also......

    I also clean the now clear glass with a qtip and alcohol, it is amazing the surface tension a little speck left behind creates.
     
  15. william13

    william13 That's not me

    Messages:
    983
    Location:
    Florida
    C_dk: in the forums, so many types of paint are mentioned, some say rustoleum gives a visible difference compared to the original McIntosh black. Is it the thickness that matters or is the rustoleum "off-color"
     
  16. c_dk

    c_dk Addicted Member

    Messages:
    6,314
    Location:
    West Michigan
    I buy small cans of rustoleum gloss black as Terry suggested and trowel it on with a flat bladed screw driver. I put it on thick to minimize tiny bubbles. It has worked for me but your results may differ.
     

     

    Please register to disable this ad.

  17. slowpat

    slowpat Slowly but surely.... Subscriber

    Messages:
    4,000
    Location:
    SF Bay Area, CA
    I have used Rustoleum as Terry suggested as well, and mine came out fine. I did scrape off all loose flakes before applying, but seems like the more I scraped , the more flaked off, and got me worried a bit on one glass pane where the a big patch of bare glass was....
     
  18. 62caddy

    62caddy Trust but verify Subscriber

    Messages:
    9,592
    Location:
    NEPA
    An artist's paintbrush with some Testors black model paint worked perfectly for me.
     
  19. william13

    william13 That's not me

    Messages:
    983
    Location:
    Florida
    I guess I will get both Testor an Rustoleum and compare.
    Thanks

    EDIT!!!!

    Now question on screening. Most describe a screening off technique with tape to square off the area to be painted but there are posts indicating putting tape on the inside b;ack paint will cause that paint to come off when the tape is pulled off. How is this technique accomplished?
     
    Last edited: Oct 22, 2015
  20. william13

    william13 That's not me

    Messages:
    983
    Location:
    Florida
    Sorry I edited my last reply not realizing it would not be put in proper cue for a response.
    One remaining question: Now question on screening or squaring off the area to be painted from the area with good paint. Most describe a screening off technique with tape to square off the area to be painted but there are posts indicating putting tape on the inside black paint will cause that paint to come off when the tape is pulled off. How is this technique accomplished?
     

Share This Page