Is there supposed to be some kind of foil backing on the inside of the headlamp, behind the mirror? I think I've read on the forum before about putting this in, but can't seem to find the product in the catalogs. Any suggestions on what to use, or can I use the lamps (gas, not electrified) without the backing?
There should be a thin pad between the back of the Mangin mirror and the headlight bucket. That protects the silvering surface from rubbing against the bucket. The mirrors do not get very hot so that is not the issue. It is more to protect the silver surface.
Several of my lamps had asbestos pads behind the mirrors and I reused them. They are not very thick but when you tighten up the mirror mounts, it provides a "cushion" against the bucket.
I have used exhaust wrap cut to fit the concave space behind the mirror. It is about the same thickness as the asbestos I found in the lamps and seems to work well. Also, the vendors sell a pad for this purpose.
I would not mount Mangins in a bucket without the pad. For the metal repops, it doesn't matter.
Ken in Texas
Thanks for the info, Ken. I will order some exhaust wrap and see what happens. I presume you don't need to adhere it in any way.
I got some 2" wide at my auto parts house, cut to fit with scissors and didn't glue it down. It has stayed put with just the three mounts and mirror.
I insulated the bonnets with that stuff but that probably wasn't necessary. I did glue that to the inside of the bonnet and the top of the bucket. However, the bonnets don't get hot if you drive the car.
Ken in Texas
FYI welding supply shops also sell insulating pads that are very flexible and easily cut with scissors.