Sarah, I followed advice offered on this board (sorry, can't remember who!) and started using Johnny Wax (toilet bowl wax ring, available at any hardware store cheap) at ambient temperatures. It's sticky and clingy and tenacious and reasonably easy to apply I suppose that if it were slightly warmer it would go on a little easier. But even at its stickiest it's not bad.

But to take a stab at your question I think "not too hot" means "not warm enough to drive out liquid from the plant tissue". Certainly you wouldn't want anything to sizzle, nor would you want to see bubbles on the pieces. I'm guessing that a baby's bath water would be a good guide, but duration is important too- a quick dip would be safer than a long soak.

The use of grafting wax is optional, and if you're using parafilm or some other tape that seals well you may well choose to dispense with it.

Good luck,

Mark

Thanks Mark for that answer I want to try grafting this spring for the first time, and I will be using parafilm. I was not sure if I still needed wax, guess not! Good idea about the toilet ring though. I just installed a toilet 4 days ago.
I'm buying wax for sealing mushroom spores in logs, you do heat that up, They did not mention a specific temp though. It's a non-petroleum wax. As they suggest. Parafilm must use paraffin, which is a petroleum wax, maybe why you use it? Appears to be anti-fungal.

When using Doc Farwell's...you don't want to go back to wax.

Here is a link that might be useful: Konrad's modified bark grafting

I don't use grafting wax either. Parafilm is much easier.

I seal all my bench grafts with wax. I use canning wax plus some toilet bowl wax mixed in. I melt my wax in a large glass jar that is in a pot with water in it. Double boiler type method. I use an electric hot plate to provide the heat. Remember wax is flammable! I keep the heat just high enough to keep the wax melted. I have done 100s of grafts and it works very well. I just make a quick dunk with the scion end into the melted wax.

Sarah80; you may be confusing the dipping wax you see in commercial grafting videos with our traditional Trowbridge's grafting wax. The melted dipping paraffin wax is from the grapevine industry, and is used on grape grafts. It is melted in a crock pot and is liquid state when the grafts are dipped; some grafters just dip the tip of the scion, others dip the whole scion.

What is much more common in the USA is Trowbridge's wax, which is warmed by your hands into a putty-like consistency and smeared on the graft. The other is a yellow paint-like emulsion called Doc Farwell's Grafting Seal, which is applied with a brush.

I have found both of these to make a huge mess and be difficult to work with, and now use parafilm tape exclusively to wrap the entire scion. The only time I'll use the goo is when I do larger topworking bark grafts and I have to seal a big area.

Sara I am old school I still use wax. I use a real small elect. crock pot. It is real small only holds about 2 cups I turn it on low as soon as the wax melts I use it have never had any problem. When I first started grafting had lots of failures. When I started covering complete graft and sicon started getting almost 100%. Might not be the wax I don't know it just works for me. Hope this helped

I dip both scion cut ends in melted wax prior to storing them in the fridge, and I also dip the pruned/cut upper end of scions prior to grafting. Since I have never done bark or cleft grafts on branches thicker than 1-1/4", I just wrap the square cut branch tops with a few layers of stretched Parafilm to seal them. Rather than continuing scion wrapping with spiral-wrapped stretched Parafilm from top to bottom, I now go a different way. Weak/dinky buds sometimes have a tough time pushing through the film, so after the scions' bottoms are taped up to the r/s, they get full length sprayed lightly and from multiple directions with a coat of aerosol acrylic clear coat paint. The c/c poison kills pathogens on the scion and dries quickly before soaking down. Even the tiniest buds can push through the dried, light c/c coating.