Fair point, UC isn't really a cavity wax, more of a underseal type product. Dynax cavity wax is called S50 and it isn't clear/ colourless more yellowish. UC itself is clear.
If put on thin it is somewhat clear (yellowy?). I planned to do our wheel arches in it but had Dynax UB left in the nozzle so it came out browny. Just did it all in UB in the end.
As @Ermintrude says S50 cavity wax is brownish (could be sort of a yellow, but you get the idea). UB is a black brown colour, it looks black over black paint, but has a brown tinge. UC is pretty colourless, but will make shiny paintwork into matt.
Another vote for UC - the areas below the fuel tank and the engine seal are done with it. A little too brown for you?
Exactly the bits I want to do ..... I’m not putting the firewall insulation on so cut the tabs off ... Did you just rattle can yours ? Colour ? I will probably use S50 in some like the swing arms and the UC on the bits you see
Can’t beat Dinatrol cavity wax. Fairly clear. Expensive in aerosol form. Better to buy it in 5ltr & use a spray gun.
I decided to clean up the firewall insulation and coat the backing material with PVA to stop it falling apart - good luck with getting that glue off the firewall! In the top photo, all I’ve gone is use an airbrush with cellulose paint (Ivory White from Jawell Paint) to blow in over the scratches. Vast majority is original as per how some German bloke daubed his spray gun around in 1974, leaving it pretty thin in many places. On the opposite firewall which was much more battery acid corroded (see http://thelatebay.com/index.php?threads/two-seater-targa-topped-bus-restoration-914.75583/page-10) I used rattle can (not celly but however they get two-pack into a can) made up by the local paint shop, LE Went in Nee Malden. Really pleased with it for a can.
