Reattaching light diffuser to back of glass

[jlovda]

I'm replacing a broken glass panel on a C33. I have several thicknesses of double sided foam tape I can use. Is there an optimum air space between the diffuser and the glass or should it be as close as possible? Anyone have some good or bad personal experiences doing a project like this in the past?

Thanks

 

[VintageMac]

Why don't you check with McIntosh and see what they recommend? If the diffuser ends up the wrong distance from the glass, it won't act properly as a light transmitter to the knob nomenclature.

Larry

 

[c_dk]

Ideally the filiments would be centered across the depth of the plastic but with the variance in the bulb constuction that would be impossible to replicate......

Since most often the two sided tape stays stuck to the difuser I use some clear Allenes water based glue to hold the old tape, usually with old paint stuck to it, to the new paint. With no petroleum solvent in it it should not react with the new painted/ inked glass.

I am sure even though their new finish is now environmentally correct it still uses a water based crosslinked polymer ink so it should be water tolerant.

 

[jlovda]

I call Mcintosh and spoke with someone in their Service Dept. I got a very vague answer of "double sided tape." I tried digging deeper but he did not say they use foam tape. Quite frankly, I am more unsure than before. These 3M tapes are like steel once applied and there is no second chance. It cost me almost $180. I may try to contact Terry Dewick in a week or so and see if he has a more definitive answer. You want the filament centered between the thickness of the plastic yet the farther the plastic is from the back of the green printing on the glass the weaker the light intensity. I will have to see how much play I have moving the bulb in its rubber grommet.

 

[c_dk]

Jon would you like someone to mike a old piece of their double sided tape to get you the thickness?

The MA6900 glass i have here to match black paints to repair bubbles has no tape attached but a old MR80 glass I have does.....

Glass is 3.17 mm thick, glass and tape is 3.81 so 3.81-3.17 =.64mm is the tape thickness.

 

[jlovda]

Jon would you like someone to mike a old piece of their double sided tape to get you the thickness?

The MA6900 glass i have here to match black paints to repair bubbles has no tape attached but a old MR80 glass I have does.....

Glass is 3.17 mm thick, glass and tape is 3.81 so 3.81-3.17 =.64mm is the tape thickness.

Chris:
Thanks so much. The 0.64mm matches one of my varieties almost perfectly. Time to dive in.
John