@Adair M or
@markyscott could give you much better advice.
I forget the title, but there is a thread that explains the difference between different dead wood treatments. The PC Wood Petrifier is the exact wrong thing to use, for the exact reason you encountered. Deadwood is important part of bonsai, may as well learn how to do it. And BC and MC do have dead snags in nature.
Leo, I don’t have a bald cypress with deadwood, nor a Montezuma Cypress. I do have pines and junipers with deadwood.
Bald cypress Live in swampy areas, so I think they would naturally have black deadwood rather than the white deadwood we associate with the mountain junipers and pines. Since we don’t want our bonsai to rot away, I think the effect us created by using limesulfur dyed with India Ink. But, a person more versed in Bald Cypressshould be consulted.
I will describe the process I use to create deadwood on my pines and junipers:
Once the deadwood feature is created, I do allow the wood to dry out naturally for some time. Maybe as long as a year before treating it. The method used to actually create the deadwood can by by carving, or pulling away bits of wood by pliers. I’m not skilled in carving, I usually do the tearing away method.
I generally would not advise sanding the wood. That makes it too smooth. Natural juniper deadwood at high elevations has lotsof little grooves and checks that give it a soft texture. Something that cannot be replicated artificially. (Oh, I suppose someone who’s extraordinarily talented could possibly create something that looks close, but, us ordinary mortals can’t.)
Look at these checks:
Lime sulfur is a fungicide that can help to keep your deadwood from decaying. The problem is, if applied straight, it dries very white, and can make the wood appear as if it’s been painted. That’s not what we want. (At least, not me.)
What I do is first clean the deadwood using a tooth brush and water. Sometimes, I may have to use something with a stiffer bristle. On stubborn areas where the mildew and algae have turned the deadwood green, a bit of white wine vinegar usually sorts that out. I wait a couple days to let it dry out, and I can see if more cleaning is necessary.
For applying lime sulfur, I get cheap, disposable artists paintbrushes. The first step is to thoroughly wet the deadwood. And let it soak in. And just start to dry out. Then, I mix the lime sulfur 50/50 with water. And paint it on. With the wood being slightly wet, and the limesulfur diluted, it tends to soak in to the wood rather than just sit on top like paint. Applied straight on dry wood, it will act like paint. Anyway, the limesulfur goes on yellow and dries white.
Or rather, “whiteish”.
I once participated in a show where I had a juniper with deadwood done my way. Right next to my display was a tree that had been painted with straight limesulfur, and as it was an “alternative display”, they had it brightly lit. I mean, that white deadwood was bright! It made mine look dull in comparison. (Heck, for all I know, they may have painted it with white paint! It was BRIGHT!)
If, after a couple days, you decide you would want it a little whiter, you can do it again. Sometimes, areas of deadwood that still retain a lot of resin from the sap don’t absorb the limesulfur well. I light touch up may be necessary.
I find that once a year is sufficient to keep the deadwood intact.
Here’s an example of a juniper I’ve treated with lime sulfur:
