Do not use polyester resin. It is a dangerous material to have around the house. It will stink the house out for weeks after it is used.

Always use epoxy resin. I am not famailair with the product you mention. It seems as if it will be suitable. Can you tell how thick it is? If it is too thick it is difficult to spead over the surface and will drag the cloth up with it. I assume you are using a 3/4oz max weight cloth. 68 minute cure time is not very slow. you will be surprised how fast that time goes when the resin is curing. I use a much slower cure epoxy when glassing. It gives me some time if I need to make some adjustment. The larger batch mixed will speed up the cure time. With the cure time you mention I would not mix up much more than 70 grams at any one time. I say grams because I mix mine by weight. Never thin epoxy resin. I will not argue about this. Thinning reduces the strength of the resin, in this case probably not an issue. Thinning can also affect the curing of the resin. In some cases the resin will not cure "Hard" it stays knd of "Gummy". This is usually discovered when it is too late.

When glassing have everything ready before the resin is mixed. Lay the cloth out on the DRY surface to be glassed and smooth it out. Pour some resin in the centre of the glass covered surface and with a spatula work the resin towards the edges. When the cloth is saturated scrape off as much resin as you can. If the resin is left too thick the cloth will "Float" in the resin and not be down on the wood. Too much resin will result in a very heavy airplane.

Your second post is correct. I do not apply a second coat of resin. When the first coat has cured I lightly sand the surface and trim off any excess cloth around the edges. Do not sand through the weave. The first coat of primer shold go on fairly thick to ensure the weave is filled. Sand the primer until the weave just starts to show through.

Ed S