Rewhitening Yellowed Gelcoat

[Beenjammin]

Ive been reading about Oxalic acid & wallpaper paste to whiten uv-yellowed gelcoat, but despite the apparent enthusiasm for this method there is not much detail on how strong the solution should be, how long to leave it on, etc.

So, I'm hoping some of the kind folk in this forum can provide some tips from people who have used this method before - or at least a pointer to a good set of instructions.

Ive got a 2.5kg tub of Oxalic acid crystals (99.6%), and the fixings for some good old fasioned flour & sugar paste. Does anyone know please:

1. How many grams (ounces) oxalic acid crystals should be diluted per litre (gallon) of water for deyellowing uv-yellowed fibreglass?

2. How long should I leave it on before washing off?

3. Will it damage aluminium toerails/portlight surrounds? Other deck hardware?

4. Will it damage/polish polycarbonate or perspex windows?

5. Will it deglaze shiny fibreglass?

6. Do I have to polish or wax immediately to protect or can it wait a few days?

Any other sage words on this topic?

Thanx in advance!