How to develop a median ridge?

[Ryan Jacob]

My friend asked me to make him a point for Christmas so I asked him some pictures from the site and he picked out a fluted one. Now, I may not be very good, but I know that you need a ridge to run a long flake easily. So how do I develop a median ridge?

[1442]

The only way I ever was able to get a defined median ridge was to have a normal lenticular cross section preform then take sets of short flakes down each side with platforms right at centerline and make them terminate just short of the midline across the point. This uses up a lot of width though and the resulting point is quite narrow for it's thickness, which is good for points with that profile but I don't think you need that to get a good flute. I believe that a flute down a median ridge would be narrower flute and it would leave the point thicker in the flute channels than if you just fluted a lenticular profile which lets the flute run wider.
Smoothness along the flute path with no high or low spots is more important  than a ridge down the middle for a longer flute to me.
with all that said though I am fairly new to fluting points and have never actually fluted anything with a good median ridge so I really don't know for sure and I reserve the right to change my mind on all of this.
Good luck with it. 

 
 

[Ryan Jacob]

I think I’ll go with that advice, haven’t tried fluting yet.

[Outbackbob48]

Ryan, when I first started flintknapping a lot of my points had a median ridges . I believe this was caused because I had a hard time getting flakes to go past center therefore forming a median ridge. Median ridges come with short flakes that terminate close to or short of center. As you get better at knapping your flakes tend to go past center for better thinning an a more lenticular preform. Now I  have to revert back to when I was a begineer knapper an try and get short flakes that terminate near center. I also believe for good flutes you need good lenticular shape from base to point, any dips or humps will effect the length of you flutes. Hope this helps. Bob

[Ryan Jacob]

Forgot to mention that my pounts are gonna be about 1/8 of an inch at their thickest point because I ran out og 1/4 slabs. Also, what causes flakes to dive?

[Outbackbob48]

Ryan , if your points are only an 1/8" thick you have already missed your chance to flute I have never used slabs when doing points for flutes also. As far as flakes diving I would say your points are flat , flakes travel better over lenticular surfaces. Just my .02 worth. Bob

[Ryan Jacob]

I do have some 3/8 inch stuff to work with. The thing is I’m not to good at working it and am still learning indirect

[1442]

I have fluted slab points. I posted one in the flute thread recently with some process pics.
1/8" is mighty thin but you may be able to do some folsom type points about 5/8" wide, maybe 3/4".
3/8" slabs are perfect for pressure flaking a preform to be fluted. Take short flakes on the first pass  all the way around on both sides to get convexity started, then continue passes all around both sides until the edges are thin enough to do a zig zag finish pass to get rid of the remaining square edge.
Then flute it, flip it, and flute it again, clean up the end and give it to your friend.

P.S.
I've even left an island of saw marks in the mid section of thin slabs just to have all the thickness possible in that area, like convexity with a flat spot.

[Ryan Jacob]

Oh, that’s why, I’ve been thinning my 3/8”” stuff to under 1/4””. So I’ve been making them too thin, which is why even though they’re not breaking, they weren’t doing what I wanted them to.

[1442]

yeah,
flat surface contours are not easy to knap without step flakes and then they look like a pancake when done.
Even slight convexity helps the flakes to terminate smooth and greatly enhances the finished look of the piece.