[Bob Carnie]

chemist say add a pinch under a gram of Sodium Sulfate before adding in Metol... true chemists can tell you why
You are following the mixture... I hope you are not adding hydroquinone.

I use a grade 4 paper setting my paper is Ilford Warmtone or ILford Mg4
It sounds like your paper flasher needs to be built as I cannot see how you did not get maki lines.
are you doing film.... my film is FP4

anywhere near normal exposure , bracketing up and down should work for film
all you need to do if its print is a multiple density test step on paper and try different powers of lights on paper and you should
be able to find your sweet spot.

I solarize from camera... are you using sheet film??
I do not know what sandwich method means.

Thanks for the detailed information.

I'm not a native English speaker so I don't understand what 'pinch sodium sulfite' means.

I tried the process yesterday but either my sodium sulfite (6 years old) was oxidized or my flashing was too week, got no Macki lines.
I used a paper flasher from RHD and I increased flashing up to 20 sec. May be the lamp is too week. I'm going to build a device similar to yours where I can change both time and intensity.

I've to add that I took the negatives with a camera. Is it better to use the sandwich method in the darkroom?

What kind of film is best?