I wonder if anyone has tried this method before!
When I make the cut on either the rootstock or the scion wood I seem to have a hard time making the surface of the cut as straight and smooth as I would like. I purchased a small block plane and find it makes all the difference in the world. I can make perfectly smooth and straight cuts using the block plane. I dont like to use the tongue/cleft method as it makes an unsightly graft as the tree grows older, so I simply use electrical tape to bind the two surfaces of the rootstock and scion wood together. Don't get frightened just yet; I put the tape on the wood in reverse with the non-sticky surface toward the bark of the tree. One can make a very secure graft in this fashion finishing off with a good coating of grafting wax. Try this; you might like it!

Dutchman

Interesting Experimentation! As far as making a straight cut on the scion and rootstock, the block plane sounds good, but I'm finding the technique difficult to envision. At the HOS grafting classes this spring I did notice a problem with knives. It was suggested every participant bring their own, and there were a number of loaners - very sharp "paring knives." Most participants were having difficulty achieving straight cuts. I tried several knives and quickly discovered the problem. Their thin steel blades allowed them to flex, causing a concaved cut. Never clean or smooth, the torn edges on both scion & stock weren't looking good...
What did work were our "real" grafting knives - ridged stainless steel blades, sharpened from only one side (though mine came tapered from both?). I've heard that a "good grafter" can make the cut in one slice - I'm getting better... But I've found that careful "whittling" can bring them to precision! But no tongue? It's a mechanical measure that maintains the critical alignment of at least one side of the cambial layers. With a scion and rootstock of identical diameter, "just taping" might work fine, but size discrepancy is generally our greatest problem.
And Electrical Tape... the debate continues~ I use it for top-working all the time; but for bench-grafting delicate scions... it's primitive. Modern budding-bands are best: they give controlled tension at the joint; shed rain; exclude air & moisture; allow for expansion; and eventually decay from sunlight. What more could you ask? (just get the "Big ones!") Other than dabbing on a drop of grafting seal to the top of the scion (to keep it from drying out), you're set!
My concerns without bands, or tongues: a shifting of scion alignment; bending, twisting, or pulling away - and if you've bound it extremely tight; a restriction of the natural expansion. And with grafting "wax" over the electrician tape you've formed a very hard "cast."
I've never noticed an "unsightly" union caused by the "tongue" of a whip? Eventual burls are due to a slight incompatibility, or a vigorous scion with too restrictive a rootstock. But one thing about avoiding a "tongue" - that's where the bloody digits happen !

Dutchman,

Sounds interesting. Do you have any digital pictures showing the method you used?

I must reply to the possibility of incompatibilty with the grafting method of the use of tongue or no tongue! I have used both methods with the same rootstock and scion wood and the use of a tongue does in my opinion leave a more unsightly graft. I will admit that the unsightly graft could be due to my inexperience at making said grafts; but nontheless I still prefer not using the tongue method and have good success not using it. Also; making the graft "stiff" or "hard" doesn't seem to effect the graft any. I try to leave a flag on the end of the tape when I finish wrapping the tape around the graft. In August I carefully remove the tape or carefully take a knife and cut the tape longitudinally and peel it off. When electrical tape gets warm it starts to stretch so the graft can expand all it wants or needs to. When the warm weather gets here the tape will expand all it needs to.
If one is still going to use the tongue method, try to "rock" the knife back and forth to obtain the cut. Trying to get the cut all at one push of the knife , even with the sharpest knife, is asking for a cut of ones digits.
I don't have digital pictures and wouldn't know how to post it as I'm borderline computer illiterate.

Dutchman

The best kept secrete about grafting is that it really isn't brain surgery. I recently looked at an "Egyptian Graft" bound with papyraceous reed (my 12 year olds doing a report on "grafting"). It wasn't close to sealed, but I assume they were successful?
Being diligent and meticulous seems to help; monitoring and "unwrapping" your (inside-out) tape will certainly add to your "takes." Maybe I've just gotten lazy - and less experimental? But most of what I graft anymore goes home with somebody else... so I figure the bands will make up for any neglect.
I once used electricians tape on "one year" wood; I'd curiously peel it away to look over the amazing callusing of the union. But my curiosity's long been satisfied and I just want something carefree and reliable. I've also found rocking, or, pulling -sideways- on the knife for the tongue-cut "feels" safer. I don't go as deep with my tongue-cut as some, but I'm actually a bit jealous of those who do / can!
The biggest problem I've found with the grafting (or budding) bands is that I can only purchase them in an eight-lifetime supply ! It's difficult to find the biggest ones, and with such a massive amount, they'll often go brittle before I can use them... But I've got plenty of electricians tape!

I always cut the tongues a little ways toward the tip of the scion and rootstock. That way when the pieces are slipped together, the centers are in alignment and the outside of the graft looks like an original twig. I then wrap with rubber electrical tape instead of the vinyl electrical tape. The rubber tape is a little thicker and more pliable. I use my utility knife to slit the roll of tape to half its 3/4" width and use about a 4" long strip on each graft. Rubber tape costs about $3 per roll.

I use a sharp blade in a utility knife to cut my scion and rootstock too, the blade is stiff enough for up to 3/8" wood. The larger handle and shorter blade of a utility knife also makes it easier to control than a paring or grafting knife. The blade is easy to retract and extend too with its thumb-operated slide. Always do your shaping of the scion wood joint before trimming to the number of buds you want to keep, that way you have a larger handle on the scion for better control.

When sealing the graft, a lot of people are now adding an overwrap of parafilm or cellophane to keep the entire scion piece in a mini-environment. This helps to maintain moisture in the scion until the graft calluses and begins to supply nutrients to the scion. I think this is absolutely necessary in certain trees as the sap flow is not as generous to overcompensate for transpiration losses. Apples are very forgiving and seem to have excess flow. It also helps to minimize the length of your scion to one or two buds - select wood with closely spaced buds to minimize the length.

When selecting a place to graft to an old tree, I've found that when you cut off a large branch there is a lot of energy that gets localized at the cut. Just look at any topped tree under a power line for an example of how trees regenerate at the cut. When you put a graft into a topped tree it seems that the success rate will be higher.