Removing massive cake

I use a PipNet reamer for getting estate pipes opened up . It features four different sized heads.

http://www.pipesandcigars.com/bjranepipetool.html

Ditto that! I have the same reamer set Arthur linked to, and it is truly awesome...really works great.

I agree with Arthur. Start with the smallest size that touches both sides and take your time. Don't try to force the reamer or you're likely to break of large chunks of the cake and expose bare wood. IMO the PipNet reamer is a must-have for restoring estate pipes. You may also see it sold under the Castleford brand name.

Wow, quarter inch of cake! Yuk! I don't think a conventional pipe reamer will do you much good, as you don't want to ream the chamber only a quarter or half way to get down to the lower half. Better to open up the chamber first with fine grades of sandpaper, wrapped around a wooden dowel, smaller than the diameter of the reduced chamber bore of course. Then its just a matter of getting into it. I listen to tunes while I work, or talk radio to pass the hours. When the chamber is opened up sufficiently to get a reamer down far enough, then ream away till your left with a cake the diameter of a dime. Some say the diameter of a nickel, but that's too thick for my taste. Some say they maintain a cake the thickness of a piece of paper! That's too thin for me. I go for the dime diameter for my cake. After 20 yrs. of reaming, I think the best reamer around, by far, is the British Buttner Pipe Reamer. Hope this helps.

A while back I cleared all the inherited cake from an estate pipe by filling the pipe with brandy and letting soak. Of course I had to prop it up so as not to pour out. Also, sterilizes the pipe at the same time. The particular pipe actually took me a couple of soaks to get it all out. I would let it sit for about 15 min then wipe out what was lose. I went all the way to bare wood as the thought of using a pipe with someone else's cake just bothered me. Some new pipes come bare and there is a break in period so i wasn't too worried about hurting the pipe. Just be carefull when filling the bowl. Don't want to spill onto the outside of the pipe and ruin the finish. Smokes great today.
This may be one of those sins that some of the more experienced guys here may cringe at, but it worked for me and I plan on doing it again.

I tend to use a small penknife blade to peel off slivers of cake. It takes a delicate hand.. and I wouldn't do this with an expensive pipe, or a pipe that had a very flush, straight inside rim. For the levels of carbon you've got in that older pipe, it may be a much faster way to come down from the thick accretion, after which you can ream more carefully.
Practicing on a corncob or a throwaway pipe is worth the learning time. It's a lot like using a handplane; you learn the angles and then can peel it away like rind on a cucumber, but there are always those early mistakes that leave a permanent scar. This also doesn't do a heck of a lot for cake at the heel of a pipe.. But like eaglerico, I don't keep much carbon (I tend to ream down to just above bare wood -- not cutting away any wood, but so that you can see it through a thin layer of char) and have yet, in 9 years, to burn out a pipe. Everyone's style is different, though; what works for me may be murder for someone else's way of smoking.

I restore estate pipes all the time and when I get them caked so thick, I take a dremel tool and use a cone shaped sanding bit and fix the pipe in a vise and slowing and steady insert the bit into the bowl and it does a great job bringing the cake down. You have to be careful and not touch the sides of the bowl and be careful of the carbon dust created.

A senior reamer is what I use... And the dremel... But that can get dangerous, I've ruined a couple of pipes that way