I am wanting to cut some cores for a wing.
I have only ever cut solid cores and this one needs to be hollow.
What do I cut first, the outside or the inside of the core?
And what is the best way to feed the wire down the inside of the core to be able to cut the inside?

Thanks in advance
Lionel.

After cutting the cores, make a jig to hold the cores and bucks.  May have to tpe them together.  Find a good verticle surface to attached the whole thing to.  Now a cou0ple of eyelets to hold your music wire(that is what I use).  Make sure the core is up from the floor a foot or two.  As Bill says line up the wire with the center of the core.  It hae a spring type clothes pin, great.  That is to hold the wire above the core.   Grab your butane torch. Double check everything to make sure all is verticle and straight.  Now light your torch and heat up the end of the wire to a nice glowing red, not white hot.  Release tlhe wire and what for it to hit the board I forgot to tell you to put below everything.  Other wise you are going to have a scorch mark on your floor.  Wait for wire to cool before taking hold of it, don't ask me about that.  Then line up for the next hole you want to punch/melt out. 

Now you can feed your cutting wire thru the holes and cut the inner portion.  Hope you have a switch on your foam cutting machine as you will have to remove the heat before and after the cutting.  With the templates I use, I usually wind up with a partial faom spar part way from center to mid point of the panel.  You know it is easier to do than tel about it.  Bob Furr here on the forum has a video for doing foam wings.  He can be found in the members index by doing a search, unless he sees this first.   

Thanks Dave and Doc,

I will start cutting the wings next weekend, good idea to make the starter holes before the wing gets cut.

Lionel

Been cutting foam wings for a long time now... go out to youtube and search on foam wing cutting... one of the videos that will show up is 8 minutes or so of a two hour video my son sells.    My personal preference is to not core a wing until it is sheeted but that is because I seldom have an oops coring them anymore (and because sheeting a cored wing can introduce warps as the hollow wing tends to flex more until the sheeting is firmly in place).   Putting the starter holes in them though is probably a good idea.   Have fun... one of the most enjoyable planes I have is a sport stunter with a light paper covering on the wing put on with thinned elmers glue.   Scares the crud out of you when the covering is still wet as it weighs so much but when it dries it makes a tough, lightweight shell that you can finish with low temp iron on film.   
Bob Furr