Unable to edit nodes after welding

I discovered after scanning some letters that the “insides” of some letters (think the “bowls” in capital B) were separate from the “outside” of the letters. I know I can Group the two objects (inside and outside) but the grouping can easily (for me) be undone accidentally. It appears that the only way of permanently joining them is to Weld them. However, after welding, I cannot get node edit to work; no nodes are shown. Is there a) another way of permanently joining these objects or b) a way to use node edit with welded objects?