Ilford Multigrade 500 - Light Mixing Box

Any thoughts/experience on replacing aged cardboard liner in Ilford 500 light mixing box ? As I examined mine, it seems that the liner yellowed due to age/heat which I’m assuming not only alters the color projected but also cuts down on intensity.

Also, is there advantage/disadvantage replacing it with more reflective material such as silver liner vs. pure white ?

I clearly see you coloring problem but intensity was never my problem with Ilford multigrade 500, actually quite
opposite. It's hot in that chamber at 2-3" distance from 2x300W bulbs. Would stay away from flat silver. What kind of material is there right now? Never opened mine.

It is a cardboard liner but it showing it’s age. The reverse side (partially glued to the metal housing) is lighter but still somewhat yellow. I’m assuming any pure white cardboard cut to size will do but looking for suggestions as it gets hot in the box so don’t want to cause a fire.
As of light intensity, it seems little dim when using Program #1, 4.5 setting which seems to be closest to neutral white. I’ve checked the light bulbs and they both work and are 300W but different brand. Perhaps with age they degrade as well with time and need replacing. Any thoughts will be greatly appreciated. Thanks

Yesterday, after maybe 10 years I switched from Multigrade head on Durst M800 to colour head on Durst M605. I must admit that it was pleasurable experience not to have to deal with all that light, even some nice features of MGH were missing. In general MG head is one huge stove in the darkroom producing huge amount of light and heat.
As for replacement, I'm not sure?? I doubt it that it's just ordinary cardboard?? But again, Durst had their mixing chambers made of styrofoam but with weaker bulbs. Meopta color heads too used styrofoam. Just pure white heat resistant paint? One used to paint Space shuttle?
What ever you use PLEASE keep fire extinguisher (proper for dealing with electricity) around you enlarger
PS Keep us posted?

Thanks for your feedback. I’ll attempt to replace the lining with pure white acid free matte board and will keep you updated on my findings. Probably will stay away from any foam or pvc material due to heat generated by the head.

I replaced mine with a lining of the dull side of aluminium foil sheet.

Mike